I have a 97 TJ with the 2.5 and a 5 speed, just bought a 98 TJ 4.0 and a 5 speed. I’m going to be swapping a few parts to the 98 TJ, and it got me thinking. Both have Dana 30/35 axles the 98 TJ is a little sluggish with the 33’s. So I was thinking of swapping the 4.10s from the 4cyl to the 6cyl. so the real question is how sluggish will the 4cyl be with the 3.07 gears. Not planning on keeping the 4cyl when all done so performance is not of my upmost concern, but will I still be able to sell the 4cyl? Just don’t won’t to sell something that’s not gonna work. Thanks for the input!
How sluggish will my 4-cylinder be with 3.07 gears?
- Thread starter TonyTJ
- Start date
Put stock size or smaller tires on the 4cyl and hope it isn't too bad for someones taste. Swap just the rear if you want to try it first.
Or just regear the 6cyl jeep to 4.56 like it should be for 33's
I’d just regear. Yes it’s expensive but it’s entirely possible the sluggish 3.07s scare anyone off test driving it. Then you’d either discount price of regearing or (worse) have to put the 4.10s back in.
If you plan on keeping the 98 - regear or find 4.10s on marketplace. I’d still go regear route bc used 4.10s might have problems.
If you plan on keeping the 98 - regear or find 4.10s on marketplace. I’d still go regear route bc used 4.10s might have problems.
Your 4-cylinder with 3.07 gears is going to be a real bad experience to drive.
I had a 4cyl. with 3.07's and 31's .you better really love shifting because your going to do a lot of it. you will be downshifting on the slightest incline even at highway speeds. and if your in any kind of hurry to get somewhere, I would take this instead ! and a 4.0 5 speed with the same axles and tires ain't much better !
X2 though I'd call it a nightmare experience, beyond a mere human's ability to comprehend lol.
The 4.10s will just make the 98 tolerable, not great. Gear it to 4.88 and call it a day. Trust me, you won't be disappointed.
You will be disappointed in both if you just swap axles.
You will be disappointed in both if you just swap axles.
Welcome to the forum. Check out the threads in my signature line for more about the 2.5s, and also for more about the 97s.
I've never heard of anyone wanting to downgrade the gears on a 2.5. I think you might also have to go down in tire size. Keep in mind that most SEs came with something like or 28" tires anyway, so I think you'd need something even smaller than that.
I've never heard of anyone wanting to downgrade the gears on a 2.5. I think you might also have to go down in tire size. Keep in mind that most SEs came with something like or 28" tires anyway, so I think you'd need something even smaller than that.
Mudflat
TJ Enthusiast
Not for his 33's, 4.88 is appropriate for that size tire and 2.5 with 5-speed. It'd be undergeared for that size tire with only 4.56 and 2.5 engine.
yea I'd look at something like this !
https://www.amazon.com/20x10x8-lawn-mower-tires/s?k=20x10x8+lawn+mower+tires
In order to run properly the 33s with 5 speed and 4.0 you need 4.56 gears.
If you are in hilly area, you might want take a chance on 4.88 gears, but they might be a little too deep.
3.07 gears on 2.5 liter is something that will suck balls. The stock on 2.5 was 4.10, so if you want anything with larger tires, you need 4.56 at least.
As for resale - I would not touch a 4 cyl with anything lower than 4.10 gears.
If you do it at least keep a pair of binoculars in the front seat of the 2.5 to watch for a gap in traffic before pulling out! 
Thanks. But, since he's asking whether he would still be able to sell it, I guess my answer is the same!
Mudflat
TJ Enthusiast
Of course, that’s right. I forgot about his 2.5 engine.
Here is the 4.0 just picked it up today,Turns out it’s a 99, and actually has 3.73 gears according to tag on rear end. The 2.5 I was going to swap complete axels out of I dont have a bunch of money in was just thinking since I was gonna sell anyway why not get what I could off of if it made this one better. Sounds like I should just leave things the way they are and just re gear at a later point thanks for everyone’s input
