BlackNorthernJK

RE-Gearing
Most, if not all, have discovered the relative ease and luxury we have been afforded with our JK’s when looking to stuff larger tires under our rigs...however it doesn’t take long for us to also discover how poorly our drivelines accept our tire choices. Some of us may have simply picked up a set of take off Rubi tires to compliment our X’s or Sahara’s, or shopped aftermarket to pick up a set of 33’s, 35’s, 37’s and larger still! The larger the tire we toss on...the poorer our Jeeps tend to perform. What do we do? We can attempt to regain performance by increasing the output of our power plants, performance exhausts, CAI’s, chips and programmers or even superchargers. Nevertheless, increasing the output of our engines doesn’t begin to address the added stress larger tires put on our transmissions or transfer cases. Simply put, the larger the tire the greater the strain our drivelines will experience attempting to turn them, and the more difficult it is. It seems most everyone that has increased their tire size has found the benefit in re-gearing their rides in an attempt to achieve lost performance.
Many of you may find yourself in the same boat I was in, limited in your knowledge of what is required to re-gear. In an attempt to help my fellow Jeepers I have compiled the following information from various JK-forum threads, online sources and personal experience. I am NOT a mechanic, and will add that every effort has been put forward to provide the most accurate information possible...however, it is highly recommended a trained professional knowledgeable in our Jeeps be consulted if in any doubt.
First let us discuss what axle assemblies our JKs are equipped with. Much of this information is already available throughout this forum, I will attempt to ease searching for it by compiling as much as possible here.
The JK models “X” and “Sahara” come equipped with the Dana 30 front axle assembly, and the Dana 44 rear axle assembly. Some early ’07 2-door Jeep JK’s came equipped with the Dana 35 rear axle, and further still some X’s and Sahara’s could come optioned from the factory with the Dana 44 front axle. The JK “Rubicon” model comes equipped with Dana 44 front and rear axle assemblies. If in doubt see your local dealer or refer to your build sheet to confirm.
But what gear ratio do you have? If you have your build sheet you can simply refer to it for the answer. If you have a stock Rubicon you have a 4.10 gear ratio regardless of model year. If you have a manual transmission ’07 minus the ‘tow package,’ it is likely that you have a 3.21 gear ratio. The automatic ‘07’s and tow package equipped manuals typically come equipped with the 4.10 gear ratio. In ’08 the 3.21 gear ratio was dropped from the X and Sahara models in favour of the 3.73 gear ratio now standard on X and Sahara models, Rubicons’ retain their 4.10 gear ratio...and oddly enough, it would appear they dropped the 3.73 ratio in '09 now for 3.21's again.... If in doubt refer to your build sheet or consult your dealer. Or...take a few minutes with a floor jack and lift the rear of your ride...spin a tire two times and count the revolutions of your driveshaft (ensure your front wheels are chalked and your transmission is in neutral, be safe) ...if your driveshaft rotates 3 full turns plus a little, it’s likely you have 3.21 gear ratio...if your driveshaft rotates 3 complete turns and almost a 4th, possibly you have 3.73’s and again if it rotates 4 complete turns and a bit, probably 4.10’s.

Now to decide where you want to go. What you’ll need to do is find the right balance to achieve your desired goals. Referring to the following chart can give you an idea of what balance you can achieve regarding tire size to gear ratio (chart courtesy of forum member jpop):


Great! So hopefully now you’ve determined the gear ratio you require to meet your goals. Now what? Well you’ll want to get them installed of course...but what’s needed?
First...be sure to get the right gear sets for the job...meaning, be sure they are JK specific Ring and Pinion. Yes you need to do both front and rear if you want to retain 4wd. Currently as of this write up, if you are re-gearing an "X" or "Sahara" while maintaining the Dana 30 Front Axle assembly, the highest numerical ratio you can go is 5.13...as of yet no-one makes a JK Dana30 5.38 or higher. If in doubt when purchasing your gear sets...by all means, contact one of our reputable site vendors. Bear in mind the front Dana 30 and Front Dana 44 gears are a 'reverse cut', high pinion set-up.

Some MORE things to consider:
- Those of us unfortunate enough to have purchased the X model with 3.21 gear ratio will have to obtain a new carrier or locker for the front Dana 30 capable of accepting the numerically higher gear ratio. The stock carrier in the front Dana 30 equipped with 3.21’s is only really good for just that gear ratio, throwing in 4.10’s and higher will require a carrier (or locker) of 3.73 and higher ratio...the divide usually occurs at 3.54 and higher and 3.54 and lower. All of our rear Dana 44’s stock carriers, lsd’s or lockers are more than suitable to re-gear to numerically higher gear ratios regardless if you came originally equipped with 3.21’s, 3.73’s or 4.10’s, this I understand is due to the ‘thick’ ring gears our JK Dana axles were designed with...so go nuts and keep your stock carrier/locker if you want.
-if considering installing a new locker, limited slip differential etc. The X and Sahara models stock front axles have 27 splines, the Rubicon stock front axles have 30 splines. The X and Sahara models stock rear axles have 30 splines where as the Rubicons stock rear axles have 32 spline...consider this when looking at new lockers etc. A great example is when I wanted to install an Auburn ECTED locker in my rear X Dana 44, a 3.73 and down ECTED locker with 30 spline count will fit the bill.
-if conducting a simple re-gear in a low mileage vehicle, you can get away with purchasing simple install only kits. These kits include new shims, ring gear bolts, crush sleeve and pinion nuts...everything except carrier and pinion bearings. With a low mileage vehicle it is possible to re-use the stock bearings providing they can be removed from the original pinion and carrier intact. Otherwise purchase the overhaul kits which include new bearings all around...especially if you consider re-gearing yourself, there is a good reason for this.

So...you’ve got the ring and pinions picked out, you’ve got the install or overhaul kits, and appropriate lockers or carrier. Now, you can shop around for a knowledgeable driveline shop near you that is capable of installing your new setup...or, if you feel up to it, you can consider re-gearing yourself! Can it be done at home by the do-it-yourselfer? Yes it can! But you really should study up on the subject, and look over the tool list and decide whether this is something you feel capable of tackling.

Before we even begin you’ll have to consider whether purchasing the new tools, and spending the time is worth it to you. Have a look over this list of tools, some you may already have, some you may need to acquire...I’ll explain what they are for after:
-18mm Wrench/socket _____ - 5/8" socket ______ -Micrometer (able to read .001”)
-21mm Socket _______ -30mm Socket _______ -12-Point 13mm Socket
-8mm Wrench/socket _________________ -Dial Indicator with Magnetic Base
-35mm Impact socket __________________-Harmonic Balancer puller, or 3-Jaw Puller
-¾” impact socket ______________________-Dead Blow Hammer or Rubber Mallet
-½” impact socket ______________________- A Hydraulic Press, or Access to one
-Ft/lbs Torque Wrench ½” Drive ____________-Large 1/2” drive Breaker Bar
-Inch/lbs Beam or Dial Torque wrench _______- Pinion Flange Wrench C-3281 or something similar
-Bearing Splitter _________________________ -* Patience*
Note. Some other tools you may have heard of or seen in other write-ups ie. Pinion Depth Gauges or Clamshell bearing puller...these are not only extremely expensive tools, but they are not really required to re-gear our JK’s. Unless in defence of the clamshell bearing puller you intend to remove and install the carrier bearings and do so while keeping them in good shape to be re-used...being that the carrier shims in all our Dana 44’s and 30’s are on the outside of the bearings this isn’t really necessary...more on this later.

Obviously the wrenches, sockets and hammers are pretty self explanatory...but what are the rest for?
-Inch pound torque wrench- to properly set pinion bearing preload. A beam style or dial type inch/lb torque wrench is required, ratchet ‘click’ style will not suffice.
-Micrometer- required to measure shims thicknesses during setup...cannot do the job without one
-Dial Indicator with Magnetic Base- required to measure and adjust backlash...again, cannot do the job without.
-Large Bearing Splitter- required for removing inner pinion bearing from pinion gear, with the press of course
-Pinion Flange Wrench- when it comes time to crush the crush sleeves you’ll need something VERY sturdy to hold the pinion stationary while torquing the pinion nut to achieve proper pinion bearing preload.

The job really can’t be done without the listed tools...and if your scratching your head wondering what backlash and preload are..we will get to that. Let us cover some anatomy first:


The Ring Gear:
A- Top of gear tooth, aka Face or land
B- Root of gear tooth, also referred to as Flank
C- Heel, the outside diameter of the gear tooth
D- Toe, the inside diameter of the gear tooth
E- Drive side of the gear tooth(flat side)
F- Coast side of the gear tooth(angled side)


The Pinion Gear
A- Pinion Head
B- Inner Bearing Seat
C- Outter Bearing Seat
D- Pinion Splines
E- Threads

Pinion Gear Assembly - in order, missing is the Yoke or Flange betwen the seal and nut, and the oil slinger which is located directly behind the outter bearing before the seal
A- Shims
B- Inner Bearing(cone) and Race
C- Crush Sleeve (collar)
D- Outter Bearing(cone) and Race
E- Seal
F- Pinion Nut

The Housing
A- Housing, also referred to as the 'Chunk' or 'Pumpkin'
B- Carrier, or Differential, or Case
C- Carrier Bearing Caps
D- Ring Gear
E- Ring Gear Bolts

Carrier Assembly
A- Carrier (Differential, Case)
B- Carrier Bearings
C- Carrier Shims
D- Carrier Bearing Seat

What is preload you might be asking? ...the conical bearings our assemblies use require a certain amount of ‘load’ or pressure if you will exerted on them, they need to be ‘squeezed’ together ,the cone within it’s respective race in order for them to have a reasonable life span...if preload is too little or too much the bearing life will be significantly reduced, burning up and failing...which is why we measure it...pinion bearing preload can be directly measured with the carrier out of the housing while rotating the pinion gear and measuring the resistance it takes to maintain the pinion in rotation with an inch pound torque wrench ...whereas carrier bearing preload cannot be directly measured...rather we need to exceed the total housing distance from shoulder to shoulder by sometimes up to 0.015”
Carrier bearing preload is achieved with an appropriate number of carrier shims, effectively squeezing the carrier within the housing and the carrier bearings within their races. It is recommended that a housing spreader be used to ‘open’ the housing up no more than 0.020” to facilitate instillation of the differential assembly with the appropriate number of shims...however, the way I approximated this without a housing spreader was to add as many shims as possible so it took me lining up the locker assembly perfectly while giving it a number of ‘good’ wacks with a dead blow hammer to get it seated. When the differential assembly is installed not only should there be NO play from side to side between the housing shoulders... there should be LESS than no play, if you were to remove .002” from the total carrier shim stacks there should STILL be no play ...make sense? Another indirect measurement of carrier bearing preload can be obtained when measuring total torque to rotate pinion with the differential assembly installed, this number can be up to 10-20 inch pounds more torque to rotate pinion over what was originally achieved pinion alone.
NOTE: when installing the diff assembly into the housing, do not attempt to ‘pull’ the diff assembly into the housing with the bearing caps and bolts, damage to the caps, bolts and housing can occur resulting in replacement of the entire housing making trying to do your own gears at home rather useless in the end.

And what about that backlash? ...backlash is a measure of the ‘play’ between the ring gear and pinion gear teeth as they 'mesh'...it is a measurement of the amount of space between the ring gear teeth contacting the pinion gear teeth, measured with the dial indicator in thousands of and inch...you want to keep our JK’s between 0.005”-0.008” This is adjusted via the carrier shims. If you reduce backlash too much...the gears will mesh together too tightly resulting in overheating and possible premature failure of the gears, likewise if backlash is set too wide the gears will not mesh appropriately and may chip and fail. More will be covered on this procedure later.

Setting them up....
Essentially setting up your gears requires that the pinion gear and ring gear ‘mesh’ together just right ...it requires that we adjust the pinion and the ring gear so they mesh together harmoniously. Consider that all the rotational energy from our engines is being transferred through the drive shaft to the pinion where it is rotated 90 degrees to the axles ...they need to be set precisely. This is accomplished by adjusting the side to side position of the ring gear (backlash) in relationship to the pinion gear, and by adjusting the depth with which the pinion gear mates with the ring gear.
All ring gears and pinion gears are made as a mated set, and are marked as such, they should not be mixed and matched. Markings are stamped on both to identify them with each other.


The pinions depth and relation to the ring gear is adjusted by pinion shims found under the inner pinion bearing...requiring that the inner pinion bearing be pressed on and off of the pinion gear in order to adjust it. The bearings are pressed very tightly onto their respective seats on both the pinion gear and carrier in what is referred to as an interference fit ...except the outter pinion bearing which is slightly looser fitting than the others.
...the pinions depth in relation to the ring gear is ‘read’ by painting the ring gear with gear marking paint and ‘reading’ the pattern and interpreting what adjustments needing to be made...this procedure will be covered later. Pinion depth should only be read when backlash is set accordingly...and as mentioned already, backlash is adjusted via the carrier shims. The great thing about our JK axle assemblies, is that the carrier shims are located on the outside of the carrier bearings, eliminating the requirement to press and pull the carrier bearings in order to adjust shim stacks.
So by adjusting our pinion depth correctly, ensuring our backlash is set...while ALSO ensuring proper pinion bearing and carrier bearing preloads we have effectively set up our gears.

There are methods I have read that allow you to approximate initial pinion gear depth by reading markings on the pinion heads...ie. a +2 ...or a -1 may be engraved on the pinion head...this number can be used in an equation to calculate the 'ideal' pinion depth...I'm not going to discuss this as I did not personally encounter any numbers engraved on any of my pinion heads...further more...final pinion depth is ALWAYS determined by reading the mesh of the gears with the paint.

When beggining the set up, using the original shims thicknesses is a great place to start.

Now lets discuss the actual procedure required to change our JK rear Dana 44 gearingRUBICONS, with your lockers there are extra procedures required to ensure proper instalation, refer to the end of procedure list for these instructions(coming):


1. Gather and assemble all required parts and tools.

2. Raise the rear of the vehicle and support the rear axle on Jack stands high enough that you may be able to access the rear axle assembly with relative ease.

3. Drain the fluid from the axles into a suitable container.

4. With a 3/4" socket remove the tires.

5. With an 18mm socket, remove the 2 Brake Caliper bolts (A) and tie the caliper out of the way...do not just let it dangle

6. Remove the parking brake cable from their 'loops'(2)...by pulling and 'wiggling' them out they will slide out from the loop

7. With an 8mm socket, remove the ABS sensor bolts from the support plate (B)...then gently remove the ABS sensors from the plates

8. Remove the 4 axle retaining plate nuts (1) with a 18mm wrench...then remove the axles from the housing. There are no C-clips retaining the axles in...if possible have a friend pull on the axle while tapping with a mallet on the back side of the rotor to release the axle from the housing.

9. Remove housing cover.

10. Wipe the bearing caps off with a rag and look for identifying markings. If none exist it will be necessary to use a punch to mark the bearing caps in order to ensure they are re-installed exactly where they came from. It is imperative that they are not installed backwards or upside down.


11. With a 3/4"socket, remove the cap bolts...then remove the caps and set them aside somewhere clean and in order

12. You can now take a small pry bar and lever the differential out from the housing....be careful where you place the bar, do not pry on the inside spider gears of the differential. Be careful not to pry it out completely so that it falls on the floor...and be ready, it is heavy. Be mindful of which side the shims and races come from...the shims are simply sitting between the differential bearings and the housing shoulders and will fall to the inside of the housing as soon as they are able.

...ignore that the bearing caps are still on in this pic
13. Carefully place the differential assembly down. Then take the shims....measure and record their thicknesses on a sheet of paper. You can identify them as the Ring Gear Side shims(driver side), and the Non Ring Gear Side Shims(passengers side).

dyolfknip

I am really getting sick of these "vague" posts by members.......







.......LMAO....seriously awesome post man, you taught me a few things for sure....thanks a lot.

BlackNorthernJK

cont...

14. Now, remove the rear driveshaft using an 8mm wrench to remove the strap bolts at the transfer case end first. Then pull the driveshaft from the t-case yoke and allow it to rest on the cross member, now remove the strap bolts at the pinion flange.

To release the driveshaft from the pinion yoke, locate the 2 non-threaded holes on the back side, using a punch small enough to fit through the holes, gently tap the driveshaft from the yoke working from side to side from either hole.

15. Using the flange wrench, or something suitable to hold the pinion steady...remove the pinion nut using the 34mm socket...an impact gun is very handy here. Keep the pinion nut handy as well as the washer...the washer is re-used in set-up and final assembly...the pinion nut can be re-used for set-up purposes only, replace it with a new pinion nut for final assembly.

16. Use a 3-jaw puller, or harmonic balancer puller to remove the flange from the pinion ...it is tightly fit onto the pinion splines. Remove it and set it aside.

17. You can now tap the pinion gear from the housing using a dead blow hammer, or brass faced hammer. If you have some extra hands, have someone prepared to catch it...and don't be too over zelous that you smack it out of the housing that it goes flying at your friend.

18. With the pinion gear removed you can now remove the seal from the housing as it will be replaced in final set up with a new seal...the best way I found to remove it is to use a center punch and crush the seal in on itself from the edges...if you place the punch on the seals very edge...or 'lip' you can give it a smack with a hammer to crush it in slightly...gently work your way around the edge of the seal...this will release the seal 'glue' and allow you to pull the seal from the housing.

19. You can now remove the oil slinger and outter pinion bearing cone from the housing...do not lose the oil slinger, it is re-used. Retain the outter pinion bearing for use during set-up. The outter pinion bearing is a tight fit on the outer pinion bearing seat...however it can be helpful to take this bearing and hone out the inside diameter for ease of fitment during set-up as you will replace this bearing during final install. Using a dremel tool and the proper bit, you can slightly grind the inside diameter out.

20. Both the inner and outer pinion bearing races will be left in the housing for set-up purposes...these will need to be knocked out carefully prior to final install so the new pinion bearing races can be installed.

21. Using the large bearing splitter, remove the inner pinion bearing using a hydraulic press. Try to ensure that the splitter is pulling on the inner race of the bearing cone to avoid damage to the bearing...ensure that the crush sleeve is removed as well, this can be discarded as it should not be re-used in final install and is not required for set-up purposes.

22. Measure and record the thickness of the pinion shim located under the inner bearing...use this shim as a starting point when beggining set-up.

23. As with the outer pinion bearing, hone out the inside diameter of the inner pinion bearing until it is a simple slip fit onto the pinion facilitating set-up, as it may be necessary to remove the inner pinion bearing multiple times to adjust shim thickness and pinion depth.

24. A great idea at this time would be to take some brake cleaner and clean the heck out of the inside of the housing while inspecting it for any signs of unusual wear and tear. With most everything out now is a great time to scrape all that old gasket material off.

25. You can go ahead and take the new pinion gear and install it in the housing to begin the process of setting up the gear pattern. Take the starting pinion shim from the original set-up and place it on the pinion, then slip the honed out inner bearing on. Do not use a crush sleeve new or old during set-up. Take the outer set-up bearing you made and install it into the back of the housing while sliding the pinion gear assembly through the housing. Place the oil slinger behind the outer pinion bearing but do not put a new seal in. With the assistance of a friend, maintain pressure against the head of the pinion gear from the front...take the pinion flange and align the splines...with a brass faced hammer, or a block of wood and hammer, smack the flange back onto the pinion gear until enough threads are exposed that you may slide the washer back on and thread the original pinion nut back on. Be sure to put a light coat of oil on the washer before putting the nut on. Then proceed to tighten the nut down until there is absolutely no play in the bearings....continue to tighten until approximately 10 inch/lbs of torque is required to keep the pinion gear in rotation. *Note- when reading torque to rotate pinion, do not read the initial torque required to start the pinion rotating, this will result in an artificially high value....rather, take a reading while the pinion is rotating.
The pinion gear has now been installed for initial set-up.

26. If re-using the original carrier....place the carrier into a bench vise and proceed to remove the ring gear bolts...again, an impact wrench is very handy here.

27. The ring gear is lightly pressed onto the carrier, to remove it...rethread a couple bolts only a few threads into the ring gear again, then using a hammer tap the ring gear off of the carrier. Discard the used ring gear bolts.

28. Clean the surface of the used carrier ensuring there is no debris left between the mating surface of the ring gear and carrier.

29. To install the new ring gear, a press could be used...however, I simply placed the ring gear in the oven for approx 5 min. at 250F that allows the ring gear to expand slightly to fit over the carrier for ease of installation. Do not attempt to 'pull' the ring gear onto the carrier using ring gear bolts. Ensure that the ring gear is lined up nice and true when installilng it...use a couple ring gear bolts on opposite sides to ensure all holes line up properly. The ring gear should slip on flush to the carrier...then install new ring gear bolts using red locktite.

30. Place the carrier in a vise to hold it steady while torquing the bolts down. Use a star pattern similar to torquing wheel lug nuts down to torque the ring gear bolts down. (1/2" Bolts 100 ft/lbs 7/16" Bolts to 65 ft/lbs)

31. Some JK D44 ring gears use 7/16" ring gear bolts, some use 1/2". If installing a new carrier it may be necessary to drill out the ring gear holes to the appropriate size...for example, my ECTED locker ring gear holes came drilled out to only 3/8" from the factory, in order to install my ring gear onto the locker I had to drill the ring gear holes out to 1/2"

BlackNorthernJK

cont...

32. If using the original carrier, you can now remove the bearings from the carrier (or you can do this prior to installing the ring gear)...it may be necessary to cut them off with a dremel and small cut off wheel...or you may try to press them off similar to the pinion bearing removal...I actually didn't do this, as I was replacing my carrier with a new unit.

33. The new carrier bearings can be pressed onto the carrier using a hydraulic press. An excellent method to ensure they are seated properly is to try to slide a .005" shim or feeler gauge between the bearing and the carrier shoulder...it shouldn't be possible...if so, continue to press the bearings on further.

34. The carrier assembly is ready to install into the housing.

35. Using the original shims removed during disassembly...replace them inside the housing with a small amount of grease to hold them against the housing wall during carrier installation. Be sure to place them on their appropriate sides....get used to doing this as you will do this procedure numerous times before you are done.

36. Take the carrier assembly and slowly and gently align it until it is straight and true...slowly press it between the shims, it is important to be nice and even on both sides...if you are off slightly it will not install into the housing and you will frustrate yourself to no end by knocking the shims out of place...this is where patience is a virtue. It can be done...I did it multiple times...just take it easy. When it begins to fit between them...take a mallet and 'gently' persuade it back home. *Do not use the bearing caps and bolts to 'pull' it back into position.

37. If the carrier begins to bind against the pinion gear...and you are unable to feel any 'play' between the ring gear teeth and pinion gear teeth, it may be necessary to remove the assembly and begin adjusting the carrier shims. With the installation of the pinion gear...backlash may be less than .000" which will cause the assembly to bind.
a)To increase backlash you will need to remove thickness on the Ring Gear Side carrier shims. A rule of thumb is...to adjust backlash by .001" ...remove .002"-.003" from the ring gear side shim stack.
b)To decrease backlash you will need to remove thickness from the Non Ring Gear Side carrier shim stack. Follow the same rule of thumb.
C)Whatever you remove from one side you must add to the opposite side. Total carrier thickness must be maintained. ie. If you remove .006" from the Ring Gear Side...you must ADD .006" to the Non Ring Gear Side.

38. If you have successfully installed the carrier assembly...now re-install the bearing caps on their appropriate sides...torque the bolts down to 80 ft/lbs.

39. Using the dial indicator on the magnetic base, mount the base to the housing and align the dial indicator perpindicular to the drive side of the ring gear tooth. Rock the ring gear gently until you can feel the contact between the ring gear teeth and pinion gear teeth...do not rotate the ring gear so much that the pinion gear begins to rotate, you only want to measure the distance between tooth contact only...while holding the ring gear in contact with one side of the pinion tooth, set the dial indicator to ZERO...now rock the ring gear back until the other side of the tooth begins contacting and take a reading...you want to be set between .005" and .008"


40. If backlash is too wide or too small...pull the carrier assembly and make the appropriate adjustments to the carrier shim stacks.

41. Continue the above process until backlash is set. Be sure to take a backlash reading at least on three different sides of the ring gear...no measurement should be different by more than + or -.002"

42. When backlash is set, you are ready to paint the ring gear teeth and begin running your patterns. Take the gear marking paint and with a stiff brush...paint 3-4 ring gear teeth on both the drive and coast sides...some find it better to mix the paint with a little gear oil...I used it straight.

43. Now you can run a pattern. To achieve a good mesh pattern for reading it's necessary to apply some 'drag' to the ring gear...the idea is that it should take a good 50 ft/lbs of torque to rotate the pinion in order to achieve a decent pattern for interpretation...this is achieved best by using a rag or gloved hand to apply the drag to the ring gear, while rotating the pinion 2-3 times forward and back through the paint.

44. You can now interpret the mesh pattern...(refer to this link to help interpret pattern http://www2.dana.com/pdf/5717.PDF) the ideal pattern should appear as a nice diffuse oval centered between the top, bottom, heel and toe of the ring gear tooth on both the drive side and coast side. If the pattern appears to be contacting at the top of the tooth it means the pinion gear is too far away from the ring gear...increase pinion depth. If the contact pattern appears to low on the tooth...pinion depth is too deep, decrease pinion depth. The pattern may also appear more towards the heel or toe...pattern towards the heel means backlash is set too high, toe contact indicates backlash is too small.

45. Interpret the pattern and make the appropriate change...which as you guessed it, requires you to pull the assembly apart and start the procedure all over again. You'll want to focus on getting pinion depth adjusted appropriately first. Make large changes initially to the pinion shim stack by .010" until you narrow in on the ideal pattern, then proceed to make smaller changes until perfectly centered between top and bottom of ring gear tooth...by adjusting pinion depth you will inadvertantly change backlash, so each time you make a change to pinion depth, reset backlash then run your pattern check. Be sure to record your progress on a sheet of paper.

46. Some other suggestions I've read say that when installing a used ring and pinion, it can be particularly difficult to get a good pattern on the drive side due to the wear assosciated from their use...in this instance it can be beneficial to focus on the pattern on the coast side of the tooth which can be a little easier to determine.

47. When proceeding with installing the carrier assembly, a tip to make set-up a little easier is to adjust the 'total shim thickness' that being the ring gear side and non ring gear side shim thicknesses added together so that they just take up the total space with carrier installed...being, NO carrier preload. This will help with the continual pulling and installing of the carrier assembly. Just be sure there is absolutely no side to side play with the carrier or your measurements will be completely incorrect. Just remember it will be necessary to add additional shim thickness during final install to achieve appropriate carrier bearing preload. ...an example, when I was setting up my rear D44, my total shim thickness was .253" during set-up which allowed me to install and remove the carrier assembly with relative ease while ensuring there was NO free play side to side, when it cam time for final install I was only able to add an extra .005" shim thickness to the total amount for carrier bearing preload. This amount should be divided equally between RGS and NRGS...in my case I added .003" to one side and .002" to the other, however my final backlash adjustment also required the additional adjustment making it work for my set up.
...this is why a housing spreader is recommended, to be able to add the additional shim thicknesses to achieve acceptable carrier bearing preload...however, I wasn't willing to spend the extra money on this expensive tool, and I am confident my bearings will be just fine.

ben1284

holy crap talk about "you learn something new everyday" ...thanks for the insane detail

BlackNorthernJK

cont...

48. Run a pattern check over a few different places on the ring gear. When you are happy with the pattern you have achieved it is time for final disassembly, and reassembly.

49. You can now pull the carrier, and remove the pinion as before.

50. Replace the inner and outer pinion bearing races within the housing with the new races.

51. Assemble the pinion gear for final install. Place the pinion shim you determined from set-up on the pinion. Using a press with a suitable sized piece of pipe...press the new inner pinion bearing onto the pinion...be sure the pipe you use is pressing on the inner race portion of the bearing to avoid damaging your new bearing. Place the new Crush sleeve on the pinion. Apply some fresh gear oil to the bearings.

52. Take the new outer pinion bearing and place it within the rear of the housing within it's race. Place the oil slinger behind the outer pinion bearing. Install the new oil seal into the rear of the housing using a seal installer or flat piece of wood and a hammer.

53. Slide the pinion assembly into the housing as before and replace the flange/yoke. Put a little fresh oil on the pinion nut washer and install the new pinion nut with a little red locktite on the threads.

54. Now comes the most difficult process of assembly. While holding the pinion flange steady...proceed to torque the nut down to begin crushing the sleeve. This requires a CONSIDERABLE amount of torque...up to 400 ft/lbs to properly crush the crush sleeve and achieve appropriate torque to rotate pinion.
-the tool you are using needs to be extremely sturdy and capable of holding the pinion flange steady.
-the most effective way is with using the proper flange wrench with the two prongs installed behind the yoke within the 2 non-threaded holes for a flush fit
-use a suitable sized breaker bar, and a leverage pipe if necessary to apply proper torque to crush the sleeve

55. When you begin to feel the 'slack' taken up within the bearings...start checking the torque to rotate pinion with the inch pound torque wrench. As you crush the sleeve down, keep checking until you achieve 20-40 inch/lbs to rotate pinion for new bearings.
-it is very important that you reach this number, but do not over shoot it. If you over shoot it you will need to tear it apart and replace the crush sleeve and pinion nut. Simply loosening the pinion nut will NOT reduce pinion preload...doing this will achieve zero preload and will result in the destruction of your gears. The crush sleeve is designed to achieve appropriate preload on the bearings while maintaining it.

56. Install the carrier assembly with the appropriate shims from set-up, plus what is required to achieve carrier bearing preload. .005" to each side would be great. Re-install bearing caps and bolts, torqued to 80 ft/lbs

57. Re-check backlash on at least three different areas of the ring gear ...with all luck it will be set to what you had determined in set-up. If not readjust.

58. Run another pattern check to ensure pinion depth.

59. With all luck your pattern and backlash will be perfect. Apply some RTV sealant to the housing surface and re-install the cover, torque the bolts to 30 ft/lbs.

60. Work your way back re-installing the rest of the axle assembly...install the axles using new plate retaining nuts.

61. Fill the housing with the recommended gear oil and you should be golden. Trial run the Jeep on the road...nice and easy...keep an ear open for any unusual sounds. Take it on a nice easy road test for approx 20 miles, do not exceed 40mph...then allow the differential to completely cool before proceeding...this is a great opertunity to take a peak underneath to ensure everything looks good. You'll want to keep it under 60mph for the first 100 miles, accelerate gently. It's recommended you don't tow anything for the first 500 miles...and at 500mph you should drain the gear oil completely and replac it....which provides you a great oppertunity to pull the cover and inspect everything one last time to ensure all is well.

62. Congratulations, you've succesfully installed gears.

newjeeper

hello

thank you for this write up very well documented and for my learning.

however i have 2 questions.

i saw this table features at:
http://www.quadratec.com/jeep_knowle...article-26.htm

This chart is based on 65 MPH and a gear ratio of 1:1, on a manual transmission in 4th gear so I think this table is for tj and not a jk. so horse power output is not the same

correct me if i am wrong

my second question is that I do not see paragraphs 31 to 39

BlackNorthernJK

Great! If it helps even a little for anyone it was worth the effort. And thanks for the heads up on editting....corrections made

As for the chart I only mention it for the JK being that 5th gear in a standard JK is a 1:1 ratio...if you use a 5-speed manual then yes it would be 4th....horsepower is not really part of the equation at all though.

Thanks. As of yet it's still a bit of a work in progress...will continue to 'tidy' it up over the next few days.
As mentioned...I hope it helps...if even just one person.

BlackNorthernJK

Front Dana 30 procedure:(work in progress)

Setting up the front gears is very similar to the back, disassembly however is slight different.
The Dana 30 gears are adjusted exactly the same as the Dana 44...it can be a little more difficult getting the axles out however as our front axle assemblies utilize Unit Bearings...while attempting to remove my axles, I found the unit bearings seized into the steering knucles with rust...by being very careful with a large flat tip screwdriver, I proceded to 'knock' them out of the knucle with a hammer...just be sure to place the tip of the screwdriver on the outter portion of the unit bearing so as not to damage them....during reassembly, I will coat the inside of the knuckles where they sit with some anti-seize....also...our front axles utilize Inner Axle Seals, being that there is no requirement to lubricate the axle bearings as with the rear 44's...ensure that the seals do not become dislodged during disassembly, or that you do not knock the spring off of the seal when reassembling.
Also...the unit bearings are retained in the knuckles not only by rust, but by 3 bolts which have a 12-point 13mm head on them...I'd suggest purchasing this socket if you do not have one.

SHIT GREEN MACHINE

Very nice. The chart is exactly what I needed to decide if my gears were the right ones. Appreciate the effort.