|06-11-2013 12:46 AM|
This may surprise you but for that size tire (roughly a 33"), and with your 4-speed automatic, you want 4.88. Yes, 4.88. The 4-speed automatic has such a steep overdrive ratio, .69, that it reduces the highway rpms too much. I.E. it makes the highway rpms too low.. With that size tire, the engine would lug most of the time with 4.56 and would lug all the time with 4.10. With the 5-speed, 4.56 would be appropriate & with the 6-speed, 4.10 or 4.56 would be appropriate. But with your 4-speed 42RLE automatic transmission, don't even think about 4.10 or 4.56. 4.88 is ideal & will NOT produce excessive highway RPMs.
To give you a little more insight... my last TJ was stolen so I bought a used replacement with 4.88 gears, 35" tires, and the same 4-speed automatic you have. That 4.88 isn't enough gear for its 35" tires, it really needs 5.13 or better 5.38. The engine lugs with 35" tires and 4.88. But that same 4.88 would be ideal for your slightly smaller 33" tires.
|06-11-2013 12:31 AM|
|Tengis||Oh anyway, I ride 2011, JK Sahara 4Door, 4 trans. automatic.|
|06-11-2013 12:30 AM|
I have 285/70/17 tire. And I don't have any plan to upgrade bigger tire.
Now planning to re-gear my jeep. Should go for 4.10 or 4.56?
It's big decision for me. It's not about any money issue. i want to have normal and fine drive. I'm 80% town rider. 20% is quite adventurous off-roading.
Please advice, help and support me fellas.
|01-23-2012 05:58 PM|
|01-23-2012 05:41 PM|
|01-23-2012 05:35 PM|
|calkid||If you plan to road your jeep any distance and have overdrive go 4.56 for 33" and 4.88 for 35" tires. You won't be sorry.|
|01-23-2012 04:54 PM|
|01-23-2012 04:50 PM|
|05wrangler||dont mean to hijack or anything, but i was wondering how bad my jeep will be with 3.37s and 35s? i have an 05 so i have a 6spd if that helps any. just saving untill i can regear. and when i do would 4:56 be ok for me? or sometihng different|
|01-23-2012 04:39 PM|
|01-23-2012 04:38 PM|
|OKLAHOMA_TJ||How about if I go to 35s???|
|01-23-2012 03:50 PM|
Edit: correction for future searches
|01-23-2012 03:31 PM|
I have a 97 Sahara with a ford 8.8 with 4.56 in the rear. I6 with 3 Spd auto.
I am running 33s now. Will 35s be ok? Once I regear the front to 4.56???
|01-16-2012 09:09 PM|
|dodgeboy31807||That was my intentions. Im trying to price items online to get an idea of parts cost. I could set one up but its too pricey from the looks of things that I don't want to buy parts twice|
|01-16-2012 08:05 PM|
And if you're planning on installing the new ring & pinion gears on your own, it's clear from your questions that you don't have the experience required to install those particular gears. They are finicky on how they are set up which involves lots of trial and error with shims to get them to mesh properly. Not even experienced R&P gear installers get it right every time and when it's not perfect, the new gears will be toast in short order.
|01-16-2012 07:41 PM|
|01-16-2012 07:24 PM|
|dodgeboy31807||No locker, or center case. Just gears and the speedometer drive gear?|
|01-16-2012 05:57 PM|
|01-16-2012 05:53 PM|
|01-16-2012 05:47 PM|
|dodgeboy31807||Ok. Going with a 4.88 setup, will I need to change anything else or just a simple gear swap. Im trying to figure what I'll have in this project|
|01-16-2012 12:39 PM|
If you plan to go to 35" tires in the near-term future, go to 4.88. I ran 4.88 with 35" tires, 5-speed, and 4.0L and it was a perfect combination. RPMs were roughly 2700 at 70 mph which is exactly what you need to run that big and heavy of a tire. 2700 may seem like a lot but it's not, it takes more RPMs to run a Jeep on the highway after it has a suspension lift (more wind resistance) and bigger/heavier tires that are harder to turn.
|01-16-2012 11:04 AM|
with the 5 speed and 33's the 4.56 was pretty great. with 35's i wish i would have installed 4.88's...
then i swapped to the aw4 auto and that made a good difference for the 35s but still i think id ultimately like the 4.88 gears.
there is not a huge difference between 4.56 and 4.88. same with 4.10 and 4.56. we noticed that swapping from 4.10 to 4.56 was totally not worth it on one of our jeeps. even less of a difference between 4.56 and 4.88. this is why i am not swapping again.
one last thing, my jeep is set up for some pretty gnarly stuff off road but i drive it primarily on road. it gets used on both but not equally. it crawls very well in the slick rock and can manage nicely on the freeways and towns.
|01-16-2012 10:55 AM|
|InvertChaos||I recommend 4.88 for 35s for your setup. You need the higher revs to push the jeep through the air and turn the heavy tires. I had 4.56 and 33s and its perfect.|
|01-16-2012 10:36 AM|
|banks316||Back when I had my 4.0 5speed I running 36" iroks on 4.56 gears ran great 2300 don at 70mph. Since I bumped up th the to my heavy humvee wheels/tire I built a 4.7l stroker and still running 4.56 gears. When I was messing with the gear calculatter I found 4.56 would put back to stock power for 35's. I know I got a YJ but its the same motor/trans combo.|
|01-16-2012 10:19 AM|
|01-16-2012 10:14 AM|
|TJWenatchee||My 97 runs the 4.0 with the 5 speed with 4.56 gears and 33" tires. Very rarely do I find the need to rev over 2500 rpm leave alone 3000. On the freeway at 65 MPH in fifth I'm turning about 2100 RPM's.|
|01-16-2012 09:21 AM|
|dodgeboy31807||Jeep not keep and rpm not rim|
|01-16-2012 09:17 AM|
|dodgeboy31807||My only concern is running down the road. I know a 4.56 gear will cause my keep to run higher rim's, just don't want a 4.88 to rev to the moon. This is the first time I have ever changed gear ratio on anything|
|01-16-2012 08:56 AM|
|530ktm||4.0 with the 5 speed running 33 inch tires go with the 4.56, 35 inch tires go with the 4.88.|
|01-16-2012 08:08 AM|
|Jeep1992||Since you do have the 5 speed with OD and wanting to go with 35s eventually I would go with the 4.88s you will be happy with those with 33s too.|
|01-16-2012 07:24 AM|
Try this one, you'll need to find out all the specs for your trans(1-5 gear ratio) and tcase
Gear Ratio Calculator
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