Still like them after around 16K miles, Karl. The higher rated coefficient of friction should give more braking for the same pedal force. It's not a huge change like a big brake kit, but it's enough for me. If the Hawks are rated GG it will feel roughly the same, if they are rated FF like the OEM pads, the EHT will feel like you took a few hundred pounds off the Jeep. Not noticing any more dust than OEM pads, might be less. No chatter, pulling, fading, or noise. No special break-in either, and the rotors were just lightly sanded by hand to remove any glaze from the old pads.

 

The marks show almost 10 degrees of slop worn into the OEM (Sachs) clutch center. The part that presses on the springs was worn enough that it looked close to breaking. The springs were also weak, loose enough to move by hand. At 96K miles one could say it was due for a clutch anyway, but the linings had lots of wear left and the release bearing wasn't bad either.

The audible symptom was a "ting--ting" noise from the loose clutch center parts when the clutch was fully disengaged (depressed). Even slight engagement would stop the noise. A much quieter version of this noise has been there since day one of my ownership at 10K miles, then it grew exponentially louder after ~90K miles. The other symptom toward the end was an occasional "hunting" from the extra drivetrain slack at idle-throttle on flat but irregular ground. Worth noting is dirt had to be cleaned out of the bell housing from muddy water, but doubting that would have much of an affect on clutch center wear.

It's hard to say which came first, weak springs or the worn center. In any case, Sachs has re-designed the clutch disc and it looks stronger.


One could test for excess free play like this by jacking the rear wheels off the ground, and rotating the Xfer case rear output shaft/drive line back and forth in 2WD, fifth gear (direct drive), with the parking brake off. Using a strap wrench would be best since this worn clutch center was notchy, and could appear to have minimal free play until using some force or wiggling it.

 

This is a new Sachs clutch release bearing (AKA throwout bearing or TOB) with a problem. The retainer springs were re-designed in a manner that requires mirror image rather than identical springs. I ended up using a National bearing with the same re-designed style springs, but mirrored so the springs are centered on the bearing hub, and thus the clutch fork.

It actually fit on the clutch fork, but the springs rubbed in the slots and the bearing was tweaked slightly in the fork. It wasn't as obvious as it sounds, or looks in the picture. The springs have some rotational slop, and in the pic they are set vertical to make the problem eaiser to see -- Lots of mechanics would probably have just installed it. Impossible to say whether it would have made noise or wore where the spring rubbed. However, a constant-contact type release bearing should self-align flat against the release fingers with the minimal force of the spring inside the slave cylinder to avoid noise when the clutch is not depressed.

Update: The new clutch has a few hundred miles on it now. Very smooth and very quiet!

 

It's not just pretty, it's functional... The big change with the B&M 46200 compared to the factory stick is getting rid of the mushy soft rubber dampening where it mounts at the top of the shift tower. In the for-aft direction it's easier to feel when it's fully in a gear, and the position fully in gear is more repeatable and precise. In the side-to-side direction there is less movement on washboard roads -- It's a tad shorter too, which likely helps that along with the different dampening. The only negative comment is that the supplied B&M knob is generic, without a shift-pattern. The SpeedDawg knob solves that for the friends and relatives who may not remember how many gears or where reverse is. It's surprising how much better it feels to shift, and it's not hard on the eyes either.


Above is a pic showing the relative position of the 4WD and gear shift levers in 4LO and 2nd gear. The yardstick is across the front seats, which are forward a few clicks from fully rear so that the yardstick can touch the 4WD shifter.

 

This isn't a step by step. It's just notes for myself, and tips that may make the job easier for someone else. See Clutch Notes II (post 63 below) for more...

• From a version of the factory service manual: "Flywheel machining is not recommended. The flywheel clutch surface is machined to a unique contour and machining will negate this feature." The "unique contour" appears to be flat, and parallel to the crankshaft mounting surface. This is a new Mopar flywheel, and if there's any contour other than flat it is less than 0.001". Another myth busted? My main purpose is actually to check the face runout, that the clutch face is machined parallel to the surface that mates to the crank. In the pic, the face that mates to the crank is on a ground steel block on top of the surface plate. The runout spec is 0.003" max.

• If the flywheel was removed, here's the cheap way to keep it from turning while torquing (60 ft-lbs) the bolts. It's simply some bailing wire around a pressure plate bolt, and the other end is tied off to something like a control arm or the frame. The manual says to replace these bolts after removal, which I did this time -- But as far as I can tell these are not TTY (Torque To Yield) and I've re-used similar bolts before. The crankshaft threads are thru-hole, so they need a thread-lock sealer. For the pressure plate bolts (37 ft-lbs), just cross the center of the flywheel with the torque wrench while tightening. This will reduce the rotational force on the flywheel enough that compression will keep it from rotating.

• Here is the check of the runout on the installed flywheel. The spec is 0.003" max, but there is thrust play in the crank that makes this measurement less than perfect -- Hence the surface plate test first. I can get a pretty good check by slowly rotating the crank against compression with a torque wrench on the bolts. Cleanliness on assembly is critical, and this essentially is checking that.

• The clutch cover has 3 dowel pin holes, which have about 0.001" clearance (or less). The hole pattern will be off by several times that so lightly chamfer the holes, verify (or grind) a smooth taper on the dowel pins, and tap the structural part of the clutch cover with a dead-blow hammer as the bolts are turned evenly to draw the cover toward the flywheel.
• When removing the clutch slave it's hard to keep the push-rod in line with the cylinder, but tilting it more than a small angle will let fluid past the o-ring on the piston and into the rubber boot. The rod end has a spherical bushing that snaps off. It's plastic-on-plastic and can squeak -- add a dab of grease inside to the spherical bearing surface. The write-up for slave disassembly is here.

• Taking the Center Console off is an option that may help, especially with access to the top two bell housing bolts in conjunction with taking the shift tower off the transmission. There's lots of write-ups such as this one. But note that pressing on this tab (see screw driver in pic below) and rotating it forward will make pulling the parking brake full-up quite easy. In the pic below the top portion of the console was previously snapped off to take a decent picture of it.

• Despite what the manual says, there's no need to drain the lube from either the trans or xfer case.
• Normally the shift tower is left bolted on, and a 3+ foot long 1/2" drive extension is used on the bell housing bots at 11 and 1 o'clock. The one at 1 oclock is the most difficult because of a through-hole bracket with wiring in the way that must be carefully pushed upward and not allowed to get caught during disassembly or re-assembly. The shifter should be in neutral as it is lowered, then shift into 4th gear after it clears the floor pan for enough clearance to slide the trans rearward without scraping up the heat shielding. Reverse the process during installation.
• An option is removing the shift tower from the transmission, cleaning the mating surfaces, and covering it with duct-tape until assembly time with silicone form-a-gasket. The upper bell housing bolts can now be accessed with a much shorter 1/2" drive extension through the hole in the floor-pan where the shift tower was. There's also less chance to muck-up the heat insulation too. The downside is potentially having stuff fall into the transmission, and it's faster to leave the shift tower on and use a super long 1/2" drive extension (which is my preference). There's a foam doughnut between the transmission and the floor pan that has to be removed first after lowering the trans/xfer case with a transmission jack. Note that with the shift tower removed, the trans can be shifted easily with a screw driver. If the tower is removed in neutral this is a simple way to put it into gear so the splines can be rotated during install.
• Have a new foam doughnut on hand, they tend to get torn during install because they've aged and lost flexability. Small rips can be patched with silicone gasket sealer if necessary.
• The rear driveshaft, rear CV joint may be stuck in the carrier. There's a couple of secret holes on the back side where a punch can be inserted. A few hammer taps and it's out. The eight bolts around the circumference of the CV joints use thread locker. The socket is 8mm and requires a professional quality six point socket (1/4" drive). 15 ft-lbs torque on assembly.
• Remove the flywheel timing sensor from the bell housing (passenger side) so it doesn't get damaged. This sensor reads crankshaft position from the segmented ring on the flywheel, and the gap is small.
• The starter was hung by bungee cord from the little u-joint for the steering shaft, wires and heat shield were left attached.
• Recommend removing the knock sensor connector and the engine ground wires (passenger side of engine block). The advantage is that the wiring harness with a bracket fastened with two bell housing bolts can now be moved up and out of the way -- This makes it easier to get the bell housing bolts out as well as separating/connecting the bell housing to the engine. There's a heat shield over these that has to be removed first. Note how the nuts for the ground and heat shield are assembled -- The large nut with the built-in washer goes on the stud "backwards", the washer faces the inside of the heat shield. The smaller nut goes on last and holds the heat shield on. Side note: I use the NO-OX electrical grease on connections like this engine ground to prevent the corrosion that causes bad connections.
• Unfortunately, the cats and related exhaust tubing have to come out after the cross-member is removed (and it's still not easy). Recommend removing all of the rubber exhaust hangers to get it un-plugged and out of the way. Some of the nuts on the exhaust manifold spun, new hardware and lots of anti-seize went back in.
• The gas tank skid needs to be loosened and lowered to get the passenger side of the cross-member out.

The rest is pretty obvious, or I forgot about it ;-) Here's one more pic of stuff taped out of the way before removal.

As far as general setup, the rear tires were up on jack stands and the front tires were aired down on the shop floor. The concept is to get the transmission input shaft as parallel to the floor as much as practical. If it was perfect, the trans could just be moved straight in by sliding the trans jack on its casters. In reality, raising the back of a Jeep (or any other vehicle I've done) that much wasn't practical, so the jack still has to be raised as the trans is moved forward and the input shaft is inserted into the clutch. Take multiple measurements around the bell housing to engine to help keep the faces parallel while turning the output shaft to line up the splines for the clutch disc.

The transmission and xfer case were removed together, and I've extended the caster on that side of the tranny jack to keep it from tipping even with larger xfer cases. The fore-aft center of gravity for this JK was just in front of the transmission drain plug. I was off about an inch and had to re-position it on the trans jack before assembly -- Getting this right, so it tilts with minimal force, makes it much easier to remove/install. I partially inserted the 4 bolts for the trans mount, and the heads of those bolts sat on the trans jack plate, making a nice stable platform with the chain around the top of the trans.

And there's more here, including pics of my transmission jack modified to pull the transmission and transfer case together...

 

The 2007-2010 didn't come with cabin air filter capability. Time to stop breathing the dirt and getting dust in the eyes -- Noticing the difference even on the gravel road to the house. It's a Mopar screen door and filters from later JK's, plus a custom filter tray. A few little things like this and some maintenance can make a 10 year old rig seem like it's new.

 

Quick and dirty peak oil temperature. Stick on label from Telatemp with 10F increments, the square turns black at the indicated temperature. Makes a great stocking-stuffer. One of my kids takes his car to the track -- lots of potential uses...


Close-up of the Autometer 5652 OP gauge in an A-Pillar 13118 mount. It has LOLO, LO, HI, and HIHI alarm setpoints. The colors are configurable, this one is set: green for normal, red for LO, yellow for HI. LOLO and HIHI blink the selected color. Optionally it can use the dash dimmer, but it's using the feature that sets it at low brightness for the normal band all the time – That makes it a 2-wire (key-on + and -) hookup, plus the wires to the sensor. Instructions for that are here

Further back view, the gauge on the right is from Aeroforce and it simply plugs into the OBD connector. I think it would have looked more factory with both in a 2-gauge pillar mount. However, pressing the buttons on the Aeroforce seemed easier for me where it is.



Gauge wiring with side trim panel removed.


New oil pressure sender installation. The trick was to take the passenger side fender off – Only takes 10 minutes and the access is pretty good afterward. Another trick, pipe dope and leaving the first two threads bare. This allows an electrical ground, as well as keeps thread sealer from entering the oil gallery – This location is after the oil filter, so this area of the engine was thoroughly cleaned before removing the OEM switch. The 1/8 NPT side of the bushing was re-tapped a few threads deeper for better strength, which was going a bit overboard... The tee was installed first, then the bushing, sensor, and switch. The clamp on the water hose was removed to swing the tee the last turn. The front cover is aluminum, so the max torque is less than with steel or cast iron.

The sensor faces rearward in a protected location. Sensor wiring isn't connected in this pic -- The wires are routed inside split tubing and make a u-turn above the motor mount, and then up towards the TIPM and across the top of the firewall to the penetration on the drivers side.


The key-on + (pink w/ lite green stripe) and ground (black) are from the stop lamp switch. For access, the lower dash trim and radio amp were removed. Power is from a 10 amp fuse in the TIPM. A 3 amp fuse for the gauge is unnecessarily large, but was on hand. It just needs to be significantly smaller than the 10 amp fuse so it will blow first in the event of a short circuit with the gauge.

 

Here's the Mopar parts list PDF for a 2008 JK, which will work for most parts with all 3.8L equipped JK's. Very handy to search for less common parts, a great reference. Search the PDF in the usual way, look in the nearby diagrams.

 

With the hotter weather arriving, decided to change out the Denso TT plugs out to NGK Iridium IX 2314 and see if I can add some spark advance back to the tune in a few places.

Turns out that the Iridium IX plugs (copper core w/ iridium tip) have less tendency for KR at higher IAT/ECT temperatures. However, this isn't a fair comparison given that the Denso plugs had a lot of miles on them. In any case, this allowed advancing the spark a bit closer to stock, mainly with IAT/MAT and ECT base corrections, but also a bit more on the WOT and the WOT Thermal base table. Compared to stock; the WOT spark at 100 KPA MAP is running about 1.5 to 2.0 degrees less than stock now. The KR occasionally bounces 2-3 degrees on a 90F day and is barely noticeable -- It pulls pretty good for a 6-banger with pushrods

The NGK 2314 heat range is the stock #5, but with about 1000 miles on the plugs I'm tempted to try out the same plugs in heat range #6 (NGK 2315, one step colder) and see if it will take some more spark advance. From memory, the OEM Champion plugs and the Denso TT plugs had about the same spark knock in hot weather. Both the Denso TT and OEM Champs have precious metal on both the tip and ground. The NGK IX plugs only have an iridium tip, so their maximum life is about half (~50K miles), especially with a wasted spark ignition system.

Nov 2019 spark plug comparison update:
I tried the (above mentioned) colder NGK 2315 plugs and didn't notice any improvement with KR compared with the 2314 plugs. Next was a set of Bosh 9661 double iridium plugs, which essentially logged the same KR numbers and performed the same as the NGK's -- However the double iridium should make them last the longest.

Bottom line: The colder plugs didn't affect KR, and the top tier plugs from NGK and Bosch preform very similarly in the few thousand miles I compared them. And, just simply changing plugs with a lot of miles might reduce KR (spark knock) even though they don't look bad.



Acronym reference
KR = Knock Retard
IAT = Intake Air Temperature
MAT = Manifold Air Temperature
ECT = Engine Coolant Temperature
WOT = Wide Open Throttle

 

Do you have more pictures of your TOB? I bought a National from advance and the inside seemed to be offset by a solid 3/16". I went down the road to O'Reilly and their National was also offset, but just a smidge less. I asked them to order a couple more for me to view....hoping they're centered. I don't recall my previous bearings being offset in the middle and none of the diagrams from the manufacturers show it that way (advance, O'Reilly, Rock Auto, Mopar parts dealers). The only thing grabbing my attention with the National is the 3yr warranty which I'm sure I'll be due for one within that period. For the point of conversation and information, I'll get pictures and hopefully have them uploaded tomorrow.