Upgrading to 4.88 Gears

[2021Willys]

Currently running 285/75/17 Toyo Open Country AT3 tires on a 2021 Gladiator Willys automatic. My ultimate goal is to run 37x12.5x17 BFG K03 Load C when they come out later this year. I’d like to get the gears done now just to get the process started. Do you guys see any issue running smaller 34”tires with 4.88 gears for 6 months? Will the higher RPM’s cause any damage to the transmission? I live in a relatively flat prairie area so I figured 4.88 would be enough for the smaller BFG 37” tires.

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[Renegade]

I was impressed with mine on 37s with 4.88s, vs the stock 4.10 gears. I don’t think running a 35” tire would be an issue. Both 7th and 8th gears in the automatic are overdrive gears.

 

[JTGuy]

The 4.88s are the best on tires 34-38.

 

[Tommyd]

You won’t hurt anything. It will be fine until you get tires. I did same thing with 5:13s when I was still on 285/75/17s
Went to 37s and am much happier now.
you will love the regear.

 

[4-Low]

Since 4.88s are now a factory option on JL (and maybe JT?) it would be cool to find some axles in a salvage yard and just swap them in. That would be easy, and probably less expensive because you could then sell your 3.73/4.10 axles.

 

[BennieD]

I run 4.88 with 35’s You will be fine

 

[Wharton]

Running 34" tires with 4.88 gears for a few months shouldn’t cause any issues with your transmission or other drivetrain components. The higher RPMs won’t damage anything if you're driving at normal highway speeds. The 4.88s will give you better performance when you do go to the 37s, especially if you’re towing or off-roading. Just be mindful of the higher revs, but with the flat terrain, it shouldn’t be a problem. The gears will actually improve throttle response and overall performance, even with the smaller tires.

 

[Wheelin98TJ]

Since 4.88s are now a factory option on JL (and maybe JT?) it would be cool to find some axles in a salvage yard and just swap them in. That would be easy, and probably less expensive because you could then sell your 3.73/4.10 axles.

The front will swap, but the rear is different.

No 4.88 option yet for the Gladiators unfortunately.

 

[Okie Gladiator]

I agree with others that already responded affirming this. You’ll be completely fine going to 4.88 now. I’m running them with 37 Nitto Recon Grapplers and sometimes I run them with 35 Mickey Thompson Baja Legends MTZ’s. No problems.

 

[2021Willys]

I agree with others that already responded affirming this. You’ll be completely fine going to 4.88 now. I’m running them with 37 Nitto Recon Grapplers and sometimes I run them with 35 Mickey Thompson Baja Legends MTZ’s. No problems.

Are you happy with the 4.88? I know a lot of guys say to go 5.13 but I’m at just above sea level, only plan to run the smaller lighter BFG AT tire and I don’t tow a lot so I thought 4.88 would be more suited for me.

 

[Jrgunn5150]

I have 4.88 gears on my otherwise mostly stock Mojave, stock tire size.

My wife has no idea, let alone any issues. She just tootles around without a care singing Pink Pony Club like all the other Jeep owners.

 

[Okie Gladiator]

Are you happy with the 4.88? I know a lot of guys say to go 5.13 but I’m at just above sea level, only plan to run the smaller lighter BFG AT tire and I don’t tow a lot so I thought 4.88 would be more suited for me.

I have been happy with 4.88’s. The 4.10’s it had stock were actually great daily driving and off-roading with 37’s but I went to 4.88 to help me a bit when pulling a travel trailer and gear. That’s where it really made some difference for me. I think it’s the sweet spot for my use.

 

[MPMB]

I have 4.88 gears on my otherwise mostly stock Mojave, stock tire size.

My wife has no idea, let alone any issues. She just tootles around without a care singing Pink Pony Club like all the other Jeep owners.

Whoa, whoa, whoa, son.

Not all Jeep owners are singing Pink Pony Club.

Some of us are rocking to the classics:

 

[Bandit’s Lair]

Meanwhile in Bandit

 

[Dilly’S Willy]

How about 4.88 on manual tranny with MTs 285/75r17? How bad would it be on stock 32s?

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