if I had known about the planman poll there would have been another person on the it was worth it side! I had 4.10s and auto. Went to 5.13s. It made my 35" nitto mud grappers feel like stockers. it was great! I highly reccomend a regear with a tire increase. Also your driveline will work less hard getting you moving and stuff. Tranny and torque converter and stuff will likely last longer. Regear is expensive but totally worth it!

 

Yep..........had 3.73 and auto with 35inch tires.......regeared to 4.88 and I wish I would have went with the 5.13's. I will say it's much better to drive than the 3.73's but running the 4.88 gears at 70mph my rpms are still on the low side, turning about 2350rpms.

Oh well

JJ

 

So do you still notice the tranny down shifting alot on the highway? I am getting ready to pull the trigger on gears and debating 4.88's vs 5.13's as well. I am only running 33's now but eventually will go with 35's.
I was also wondering if anybody knows what rpm's 5.13's with overdrive ON will be turning at 70mph? How would it be if you had to tow something with 5.13's, overdrive off and running on the highway? Lots of questions, I know!

 

Dog Doc, I have a manual so I can't answer most of your questions, but will say that your RPM question is answered in The Chart:


These little engines don't mind RPM. I've been running 32" tires and 5.13's with a manual for months. However, I don't do much Interstate and my 35's will be here Wednesday.

 

Remember to measure the tires and use the 'actual' heights, not the mfg's listed height!!!

Here are some numbers from me looking at the dash:

Auto, 5.13's, 32" tires (295/75/16 terra's - mfg says 33.27", actual was 32")

MPH O/D off O/D on
40 - 2150
45 - 2500
50 - 2700
55 - 3000
60 - 3250 - 2200
65 - 3500 - 2400
70 - 3800 - 2600

So, use the chart to get your rpm at 70. Then divide by .69 to get the OD off numbers.



Need? Of course not.

Freeway is where you'll notice the difference the most. Around town only?? Just turn OD-Off and you can live with it.

That said, it is the single biggest performance improvement you can make. Ripp even suggests re-gearing before spending money on their s/c's. That right there says a lot...

 

My tires being 305's measured about 32.8" if I remember correctly.. and they are heavy!
Based upon the information you provided it sure looks like towing something with 5.13's and overdrive off on the highway may be pretty hard on the jeep!

 

A bit over 3700rpm at 70, or thereabouts. Personally, I would gear for the 98% of the time you are not towing instead of the 2% that you are. Just depends on how far, how fast and how often you tow.

 

I know the first opportunity i get for regearing I will do so. It's the money that is stalling me but come tax returns i will be chilling with my 5.13's.

 

Doc,
If you have an auto go with the 5.13's.............I am running Nitto Trail Grapplers 295x70 r18 with the 4.88's and it's okay.... the Nitto site says they are 34.5 inches in diameter, but when I actually measured they are closer to 34.25....1/4 inch difference. This being said most of the 35 inch tires run closer to 34 inches......... the chart posted on here is right on the mark use that to choose your gears.......and even though I wish I would have went with the 5.13's in Florida there's not to many hills so the 4.88's work okay and there's no problem with the tranny searching for gears.

Hope this helps

JJ

 

My Jeep was geared to the moon when I got it. 3.21's

I absolutely LOVE my fiveonethree's!!!!