What gears: 4.88s or 5.13?

GrimGentry

Member
Original poster
Joined
Dec 25, 2022
Messages
28
Location
Panama City Beach
I have a 05 TJ with 33x15.50-15, 15x14 wheels, 4.0L engine, 42RLE.

I am debating between 4.88s and 5.13s since my tires and wheels weigh about the same as 35s.

Also do I need to change my diff cover with different gears than 3.73?
 
5.13 still isn't deep enough for 33s. The diff covers don't know what gears you have in there.
 
  • Like
Reactions: gatertamer
I have a 05 TJ with 33x15.50-15, 15x14 wheels, 4.0L engine, 42RLE.

I am debating between 4.88s and 5.13s since my tires and wheels weigh about the same as 35s.

Also do I need to change my diff cover with different gears than 3.73?

I'm actually getting 5.13s installed in my '05 TJ today, though my 33s are 5" narrower than yours, and my wheels are half the width.
 
  • Haha
  • USA Proud
Reactions: Rickyd and jjvw
What brand gears are you going with?

I went with Revolution this time, as the installer likes them. I had Nitro in my last TJ because that's what that installer used, and I no issues with them. I'm always happy to go with whatever the shop or person installing prefers.
 
I have a 05 TJ with 33x15.50-15, 15x14 wheels, 4.0L engine, 42RLE.

I am debating between 4.88s and 5.13s since my tires and wheels weigh about the same as 35s.

Also do I need to change my diff cover with different gears than 3.73?

I have the same combination and I run 5.38s. It is perfect. If you can get that ratio for your axles, I would run that. If not 5.13s.
 
I have a 05 TJ with 33x15.50-15, 15x14 wheels, 4.0L engine, 42RLE.

I am debating between 4.88s and 5.13s since my tires and wheels weigh about the same as 35s.

Also do I need to change my diff cover with different gears than 3.73?

I am only confused about " 15x14 wheels ":unsure:
 
I have a 05 TJ with 33x15.50-15, 15x14 wheels, 4.0L engine, 42RLE.

I am debating between 4.88s and 5.13s since my tires and wheels weigh about the same as 35s.

Also do I need to change my diff cover with different gears than 3.73?

I have 4.0, 42RLE.
I made a mistake, and assumed that 4.56 will be great for my 31s. I am getting 2480RPM at 70MPH, which is not bad, but 2650ish would make it better. The reality is that i needed 4.88 just for 31s.
If you plan to use anything larger than 31s, go to 5.13. Don’t look at 4.88.
42RLE is actually great transmission, you just need to have it geared properly.
Even with my 4.56 and 31s, it drives nice, accelerates, etc. Don’t really need to shut down the overdrive, pretty much never.
 
I only listed the wheel size so people could see the weight

Are you stretching the tires?
Screenshot_20230707_060355_Reddit.webp
 
I have a 05 TJ with 33x15.50-15, 15x14 wheels, 4.0L engine, 42RLE.

I am debating between 4.88s and 5.13s since my tires and wheels weigh about the same as 35s.

Also do I need to change my diff cover with different gears than 3.73?
I'd go 5.13. And it's not wheel & tire weight that governs the right axle ratio, it's strictly the tire's diameter that does. Its diameter is what affects how much leverage it has against the drivetrain and brakes. Your diff cover will be fine with any gear ratio you go for.

But what is the 15x14 size wheel you mentioned? Are you really going to be running a 15.5" wide tire? Why? Does your Jeep also get driven on the street? If so that wide of a tire is going to hydroplane very easily and it rains enough here in Florida that that would be a real issue. And even on sand you don't need that wide of a tire.
 
  • Like
Reactions: NashvilleTJ
I'd go 5.13. And it's not wheel & tire weight that governs the right axle ratio, it's strictly the tire's diameter that does. Its diameter is what affects how much leverage it has against the drivetrain and brakes. Your diff cover will be fine with any gear ratio you go for.

But what is the 15x14 size wheel you mentioned? Are you really going to be running a 15.5" wide tire? Why? Does your Jeep also get driven on the street? If so that wide of a tire is going to hydroplane very easily and it rains enough here in Florida that that would be a real issue. And even on sand you don't need that wide of a tire.

It was on put on by the PO I’m looking at 35s in the future just going to let the 33x15.50s run out of wear. They’re cool looking don’t get me wrong but they’re terrible for articulation.
 
  • Like
Reactions: Jerry Bransford