4.88 gears with 4.0, AX-15, and 33s?

[TxFireman1972]

Anyone running 4.88 gears with 33’s and and 4.0/AX15?

Currently running 3.07 gears in my 97 (pictured) with 31” tires so Im looking to swap gears because the 3.07’s suck! I found another TJ with a blown up 2.5 in it that has 4.88 gears in both axles already and has a set of wheels/33’s. It also has a bunch of suspension, steering, bumpers etc. that I could swap over to my Jeep.

I’ve researched plenty and I know 4.56 is ideal for my situation but the deal on this other TJ is too good to pass up and I would come out way ahead, especially after putting my axles and stuff back in it and selling it or parting it out.

Just to save some time I’m only looking for feedback on 4.0/AX15 with 4.88’s and 33’s, no other combos. Thanks!

 

[machoheadgames]

4.88 is better for 33’s than 4.56. Run it and don’t look back.

 

[TxFireman1972]

4.88 is better for 33’s than 4.56. Run it and don’t look back.

I guess I should have added it gets driven a lot and will see some highway time back and forth to town. 70mph or so. With the 3.07’s I’m doing good to hit 65 with a tail wind lol

 

[machoheadgames]

I guess I should have added it gets driven a lot and will see some highway time back and forth to town. 70mph or so. With the 3.07’s I’m doing good to hit 65 with a tail wind lol

Highway will be just fine. 3000 at 75 is a good combo. 3.07 is truly terrible, even 4th gear sucks on the highway with 3.07.

Good ole Sour Lake. I grew up in Beaumont and I imagine that’s the heading into town you’re doing. Moved away 10y ago though for college and never ended up back. I miss it down there at times.

 

[TxFireman1972]

Highway will be just fine. 3000 at 75 is a good combo. 3.97 is truly terrible, even 4th gear sucks on the highway with 3.07.

Good ole Sour Lake. I grew up in Beaumont and I imagine that’s the heading into town you’re doing. Moved away 10y ago though for college and never ended up back. I miss it down there at times.

Yeah, unfortunately I still work in Beaumont, for about 3 more years anyway lol.

 

[jjvw]

4.88 is correct

 

[TxFireman1972]

4.88 is correct

thanks. Like I said above I guess I should have added it gets driven a lot and will see some highway time back and forth to town. 70mph or so. With the 3.07’s I’m doing good to hit 65 with a tail wind lol

 

[jjvw]

thanks. Like I said above I guess I should have added it gets driven a lot and will see some highway time back and forth to town. 70mph or so. With the 3.07’s I’m doing good to hit 65 with a tail wind lol

I daily drove 4.88, 33s, nv3550 for many years. The transmission is effectively the same as yours. This was the best gearing/tire size my Jeep has ever had for overall driveability, including the highway.

 

[TxFireman1972]

I daily drove 4.88, 33s, nv3550 for many years. The transmission is effectively the same as yours. This was the best gearing/tire size my Jeep has ever had for overall driveability, including the highway.

Calculators and theories are good but it’s always best to talk to someone actually doing it! Thanks for the info!

 

[Harold&Cat]

Agreed , the 4.88 gears and 33's will make your Jeep happy .

 

[JMT]

4.88 all the way. It’s correct and the best for your engine, transmission and tire size.

 

[TxFireman1972]

Agreed , the 4.88 gears and 33's will make your Jeep happy .

4.88 all the way. It’s correct and the best for your engine, transmission and tire size.

Good deal, thanks!

 

[TxFireman1972]

Picked up my donor vehicle today. 2001 with a blown up 4-cyl. Going to swap the axles (4.88’s) probably the bumpers, and wheels and tires. See if there’s anything else I need and sell what’s left.

 

[Redneckerson38]

did you get your swap done yet?
I just picked up a set of 30/35 axles with 4.88s but I'm only running 31s that are practically still brand new maybe 1000 miles on them so I'm hoping the 4.88s won't be to tall of a gear for them, but it'll have to be a 100 x better than the 3.07s

 

[Harold&Cat]

I have the 42rle which has a very tall overdrive . When I switched to 4.88 gears I ran 29 inch tires for a couple of weeks and it was fine . Didn't do any high speed driving because I was breaking in the new gears , but 60 mph was not too bad .

 

[jjvw]

I have the 42rle which has a very tall overdrive . When I switched to 4.88 gears I ran 29 inch tires for a couple of weeks and it was fine . Didn't do any high speed driving because I was breaking in the new gears , but 60 mph was not too bad .

Your 42rle has a .69 overdrive compared to his ax15 with a .79 overdrive. The two are not comparable for axle gear recommendations.

 

[TxFireman1972]

did you get your swap done yet?
I just picked up a set of 30/35 axles with 4.88s but I'm only running 31s that are practically still brand new maybe 1000 miles on them so I'm hoping the 4.88s won't be to tall of a gear for them, but it'll have to be a 100 x better than the 3.07s

I did and absolutely love it! It’s like a different Jeep. Very peppy and I can actually use 5th gear now!

 

[Harold&Cat]

Your 42rle has a .69 overdrive compared to his ax15 with a .73 overdrive. The two are not comparable for axle gear recommendations.

Actually with his 31 inch tires vs the 29 inch tires I was running his rpm @ 60 mph would be 2316 where my rpm @ 60 mph was 2340 .

 

[machoheadgames]

Your 42rle has a .69 overdrive compared to his ax15 with a .73 overdrive. The two are not comparable for axle gear recommendations.

I’d say .69 and .73 are close enough to be comparable….except the AX15 is not 0.73, it’s 0.79. So back to being not comparable.

 

[jjvw]

I’d say .69 and .73 are close enough to be comparable….except the AX15 is not 0.73, it’s 0.79. So back to being not comparable.

They are comparable again when we mix and match tire sizes. Just ask Harold.