i was told for my 88 yj with 8" lift on 36"s still has stock gears i believe it came with a 4.0 carb, and the guy i bought it off, swapped in a 4.0 efi so i find it kinda sluggish with the big tires.. I was told to look for a jeep yj with a 4cyl and get the gears our of it,, few questions i have
what years??? front and rear?? does 5spd or auto make a difference probably not.. thansk for your help!
4 banger axles wont cut it. 5spds came with 4.10s you would want at least 4.88s with your setup. I would also start looking for a ford 8.8 rear to replace your d35 when it grenades itself with those big tires.
1990 YJ soon to be 4.7L, auto, d30 4.11 w/ spartan locker, ford 8.8 4.11 open, sye, 4in RC 2in BL
I just went with 35's and have 4.10s. It's adequate. Nice balance with highway and trail. To each his own but everyone always says 4.56s or lower. Not me. Everyone has there own preference. You can find 4.10s out of a 4 banger pretty easy. I personally think auto vs manual is different. People with manuals always tend to the lower gears.
Manual trans and autos do make a big difference in what gears to run. Manual when everything is work right does not have any slipping in them ( loss of torque band). Where as an atuo does allow for this slippage and in a basic way gives to the torque band a little easier. So an auto can use a higher gear ratio and still have the torque to power through. With a manual if you where to do the same thing you would burn up the clutch. So with all that said if you have an auto with say 4.10 gears would be like having a manual with 4.58 or 4.88 gears in. This would give you about the same performance in the first 3 gears on the manual trans. Now this is where the auto comes in to its glory is once it is beyond that. The auto would still be able to power up to a speed and be under less rpm than the manual trans. You would still have some slippage in the auto trans until the TC locks up if it has one. But there is less loss energy at that point. Where as the manual trans does not have that loss anywhere.
A 89 yj with a 4.0 aw4 sye out of an 92xj. Now the hard part is done time to get it up in the air just a bit. Working on 8.8 with 3.73 and lsd for the rear. and new D30 hp with 3.73 .
For those who have not figured this out I'm old school but can handle the new too.
It's hard to tell you what you need. It's about what you want and your preference. If you a manual I'd say 4.56 or lowrr (numerically higher). If auto 4.10 might be good enough. Just educate yourself and try to make the right decision so you don't have to do it twice. Make sure your decision doesn't include the 35 in the rear. Your upgrade won't be cheap.