ok i got a 90 with a peugot( spell check) 5 speed and 3.07 gears! i have 31's and its a slug! if i put some 3.55's will i notice a difference or not really??? thanks guys!

 

skip the 3.55 and do a 4.10 that way if you ever go higher you wont be rolling so bad

 

well i plan on keepin the 31's but would the 3.55s make a diff.??

 

They would but most all XJ's with the 5 speed all got 4.10 gears fro m the factory stock for a reason..

 

No they didn't....

If he has a 6-cyl... 3.07 were standard, but every ratio was available..

And to the OP.... take another look at your tranny... The Puke-out mercifully died in 1989... So some 89's have it and some have the AX-15. 90's should all have the AX-15... but Jeep did some strange stuff in that era as Chryco took over...

 

sorry i ment 88! but will the 3.55's make a diff.????

 

it will be a little under geared for the 31's. 373 would be the way to go for the 31's

 

well i have a complete set of spare axles with 3.55's and my 3.07's are way way under gear as of right now! hahaha

 

going to 3.07 to 3.55 wouldn't be much a jump. you'd probably be better off goin with somethin a little higher like was said if you really want to regear.

 

If you have the spares and they will bolt in directly then it would save you money. But like everyone else is saying it would be better to go with a higher gear. 3.55's are higher than 3.07's.

 

3.55 is better... But if you paying to regear.. than don't bother... go to a 4.10..

But if you are sliding the 3.55's you have under there... then you will be somewhat better off... Don't forget to change the speedo gear if you have the replacement.

 

According to a tire-size-change-gear-ratio-change calculator, if you are moving from stock 28" diam tires to 31" tires with a gear ratio of 3.07; you will want to regear to "3.4" ratio to maintain stock characteristics. It also lists 3.09 and 3.7 are the high and low ratio limits you should consider when wanting to regear and keep the tire size.

http://www.greatlakesxj.com/tech/tech_calcs.html

Personally, when I regear my 4.0L 5sp with 3.07s and 31" tires, I'll probably go with 3.55s because I like the 31" size. But I can easily see someone convincing me to get the 3.73s.

 

Going to a 3.55 gear would not be a bad move up from 3.07. You can do it for hardley any money and it will be like when you had it with the 3.07's and stock tires. However, yes it would be better to run a 4.10 with them. If money is a factor though you can go get some j/y axles and get back to factory gearing for around 150 bucks an axle max. This will cost you about 1/2 of going to 4.10's. If it was me on a budget and you plan on sticking with 31's then I'd go with the 3.55's. However, I said a year ago when I got 31's I was happy. Now I'm selling them so I can run 33's.

 

Lower is always better I would look into at least a 4.10

 

If you have bolt in axles, do it