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gears for 30" tires


NAXJA Forum User
NAXJA Memorial Lifetime Member
NC Sandhills
Thinking of mommies 4.0/AW4/242/3.55:1 '88 Limited Jeep... it will get a 2" AAL/spacer/shock boost to fit 30x9.50 or 235/75. Probably be adding 35-50# of misc gear to it's running weight...mostly safety/survival stuff.

3.55 will be adequate for now...(currently running 33' in my XJ with those gears and a LOT more weight and it rots) but when I do the tire swap, It'd be neat to do the BB install and swap axles or gears at the same time. That way Mommy Suspects Nothing.

I have a 30 with low-mile 4.56 and a True Trac that would snug right in but 4.56 and 30s I dunno would make 'us' a happy camper. it'd be a hoot around town, but be revving out on the highway? If we were towing a bunch of weight routinely, that low would be fine, but for routine grocery getter chores...?

What would the experts reccomend gearing for 30" tires. My evil angel swears 4.10 is right but also sez the 4.56 will be OK. This Jeep will be rarely in 4WD and probably never in 4 Low...30's and 2-3" lift is it...anymore and I am busted bigtime ;) All my fun for this one has to be approached with stealth.

4.56's with 30's?!?!?!?!

NO LOL....Great on th etrail but Mommy would REALLY notice on the street...Even 4.10's would be very noticable on the street.

The differance with 30's and 3.55's compared to the stock 225's is minimal, not very noticable in all honesty...
I had the 31" and 4.10 which felt perfect.
Then I had the 30" and 4.10...too high rev, I thought. But fast off the line.

Im am now at 3.55 and 30" and feels, umm...pretty normal. But remember I am mostly on the pavement...
Ill bet 3.73 is the best but not worth it...
Didn't think the 4.56 would be good (they be 1/2 free if kept in the existing 30 axle...) If it were mine, I wouldn't need to ask, especially with 30" tires LOL.

For now prolly just hold with the 3.55 in the 30/35... it has 205/70-15" now so Karen is getting the 'upgear' effect. 30" prolly go unnoticed especially with a full tune-up & airtube/KN (runs nice now eh? LOL)
Woody, 31s with 3.73 gears comes out exactly the same as 3.55 gears with stock tires. Therefore, 30s with 3.73 gears would be a very driveable combination, providing just a bit more gear than stock. That's what I originally planned for the red MJ, until my brother handed over his old set of 31s.

Even 4.10s is much too much gear for 30" tires. I've been running my '88 on 30s with 3.07 gears and a 5-speed. I think for Karen the 30s with the stock 3.55 gears are just fine.
I'll tell you what,Woody,you need to scrap that 4.56 idea right now! You know the only way to fly is 4.88's :)!

Seriously,though. If you're not gonna use the 30 with that stuff in it would you consider selling it to go along with that 8.25 to fund the new gear setup? I could probably do a gear swap on the 8.25 myself,just not so sure about the D-30. Just a thought ;) Sorry,but you know I'm always on the lookout for a good deal :laugh: