Topic: automatic trans

[95yj4]

Alright I have a 95 with the auto trans. I want to do a little lift and somewhat bigger tires some time soon. I tried looking around for what the trans can handle but I cant find anything or do it and find out. I would like to know what it can handle but really what I can swap in for it so I can go bigger then what it can handle. If I missed the post or theres one someone where else on the web, please let me know/ show the link. Thx

[Bounty Hunter]

The trans will handle quite a bit, it'll handle the power the 2.5L puts out and that's what matters most.

The important thing is you consider regearing the axles if you go with a tire much larger than 31".

[dexetr30]

Yeah, the trans really isn't the weak link in the equation. It's your axle strength and gearing that come into play when you're adding larger tires. Like Bounty Hunter said... if you go over 31" you really should consider re-gearing.

[Jeffy]

The transmission is a 30RH I believe.  This is a renamed Torqueflight 904.  Strength wise it's fine but you're overall gearing may suffer a bit.  You don't have a 5th gears to worry about but that also means all your gears will be a bit higher.  You could fix the issue by swapping complete axes with a 2.5L Manual and get 4.10's, which should be fine for 31's. Swapping complete axles will be cheaper then getting the gears replaced.  Otherwise, just live with it.

[95yj4]

I'm pretty stoked then, cause I was thinkin I would have to swap everything to go over 31". I really dont want to go much bigger then 31" anyway(maybe 32", 34" max I think), but wouldn't I want to go to a different axle anyway because mine can only handle 31"? How much would my gas mileage suffer (Like it isn't already) with 31" and 4.10 gears. Alot I would assume.

[lanulos89]

my jeep 31's automatic 4.10's i like 14mpg fifteen on good days

[95yj4]

Wow pretty bad. Right now I have 4.0 throttle body, K&N drop-in, and side-gapped platinum plugs. I average 19-20mpg while gettin on it a bit.

[Colin]

I have a 2.5L Manual (1993) and I get about 16-18 at the moment running 31's and not much else. (That is also with the top completely off... if you're counting weight.) No additional engine mods yet either. I suspect when I change the TB I should get a good improvement.

Still not sure about the K&N filter, I like paper best.

[95yj4]

Yeah full doors and a hard top, so to me 19-20 is really good (for a jeep). For the filter, I run the K&N, unless I'm goin trailing, then I throw in a paper one. I'm mostly in the city anyway, so it's really not going to hurt me.
If I'm gonna try swappin the axle to get the 4.10, shouldn't I go with somethin else so it will be able to tolerate just bigger then 31s?

[lanulos89]

yea the auto trans tho strong is a DOG.....  theres no making it better so uhh enjoy.  4.10's with 31's will simply put it back to "stock" condtions. (stock meaning speedo works good again, and speeds return to normal.)  if you regear higher to say 4.88's it will most probably harm your gas mileage even more (i think)?.

[95yj4]

If I did go 31" tires and 4.10 gears, would it help to get aluminum rims to help with the rotating mass?

[lanulos89]

yes it would, im upgrading to 33's soon, and looking for a set of aluminums i like the look of.

[95yj4]

Alright looks like I need to find some rims. Does anyone recommend or not recommend certain ones?
What is the biggest tire the axle can handle anyway? I remember reading something on here but cant seem to find it.

[lanulos89]

since its only a four banger 35's, but even then you will have trouble.  33's are a safe median

[95yj4]

wow 33's, I thought it was like 31's. But hey that'll work