Anyone regear a diesel gladiator rubicon with 37's?

[aevgladitorrubi]

If so, curious about your feedback-- going up to 37s on a diesel and curious if I'll feel the need?

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[Jefe1018]

No insight on having it done, but when I pick up my JT it will also be on 37's with the diesel, so I have an interest in this topic as well.

 

[Chance575]

37s for 2500 miles now, no need to regear but I will with my air locker install

 

[tampahoosier]

I’m sitting on 37s (ridge grapplers) with 17x9 fuel militias. It’s a rubicon too and the 3.73 gears seem to be holding up. There was a bit of lost but not as bad as my 2020 gassser rubi when I jumped to just 35s.
I think in the future I’ll jump to 4.10s but I’m not in a rush. It will take some stress off the tranny and that’s important. I did notice the shift timing is def off now and it’s annoying. Yes I have a tazer and yes I did update the tire size.

 

[Jefe1018]

I’m sitting on 37s (ridge grapplers) with 17x9 fuel militias. It’s a rubicon too and the 3.73 gears seem to be holding up. There was a bit of lost but not as bad as my 2020 gassser rubi when I jumped to just 35s.
I think in the future I’ll jump to 4.10s but I’m not in a rush. It will take some stress off the tranny and that’s important. I did notice the shift timing is def off now and it’s annoying. Yes I have a tazer and yes I did update the tire size.

What fuel economy are you seeing now?

 

[BLK HOLE]

I'd do it simply because of the added driveline load. Jeep saw fit to reduce the std Rubicon gearing, for example, 10% for the diesel...so I'd stick with that personally. So I'd be looking for 4.56 low side or 4.88 high side for the JTRD with 37s. Whereas for my gasser those gears are 4.88 low and 5.13 high.

 

[tampahoosier]

I'd do it simply because of the added driveline load. Jeep saw fit to reduce the std Rubicon gearing, for example, 10% for the diesel...so I'd stick with that personally. So I'd be looking for 4.56 low side or 4.88 high side for the JTRD with 37s. Whereas for my gasser those gears are 4.88 low and 5.13 high.

4.88 is WAY too high for the diesel. The math doesn't come close to working out for that. 4.88 is one of two gearing options (the other being 5.13) for the gasser on 37s if that tells you anything. I know of one person on FB that did 4.88s for the diesel and he said he would not recommend to anyone and it's the wrong gearing for sure. He's actually contemplating spending more money to get down to 4.56.

The max gearing for 37s should be 4.56. But math wizes have pointed out the stock gearing is somewhere in the middle of 4.10 and 4.56. Cheapskates like me can do the 4.10s since there are always 4.10s available from those that take them out almost immediately and can't give them away because no one wants them. I would love to talk to someone who knows their stuff about 4.56 and what that would do.

What fuel economy are you seeing now?

Tough to say, I'm barely driving right now. It's basically 2 miles round trip on city streets with traffic lights. I'm right around 19-20. I think highway is around 21-22. I was getting low 20s in the city and hit 25 all day on straight highway when it was totally stock. I was getting the 25 highway with a boat load of gear for a 3 week trip from Tampa, FL to Cody, WY and back. I'm talking loaded cab with 2 adults and a 3yr old, loaded bed, basket on top of bed loaded, and a basket on the hitch with a loaded 65qt cooler and 10 gal of diesel.

 

[BLK HOLE]

4.88 is WAY too high for the diesel. The math doesn't come close to working out for that. 4.88 is one of two gearing options (the other being 5.13) for the gasser on 37s if that tells you anything. I know of one person on FB that did 4.88s for the diesel and he said he would not recommend to anyone and it's the wrong gearing for sure. He's actually contemplating spending more money to get down to 4.56.

The max gearing for 37s should be 4.56. But math wizes have pointed out the stock gearing is somewhere in the middle of 4.10 and 4.56. Cheapskates like me can do the 4.10s since there are always 4.10s available from those that take them out almost immediately and can't give them away because no one wants them. I would love to talk to someone who knows their stuff about 4.56 and what that would do.

I quite literally said that, lol

 

[tampahoosier]

I quite literally said that, lol

are you the guy with the 4.88s?

 

[CrazyCooter]

I feel 3.73s are perfect for 37s!

She holds 8th empty in the rolling hills, tows a 4000lb travel trailer in 7th, and 6th towing in the hills. 25ish mpg unloaded in a 6400lb truck on 37s?

Why would a person mess with that?

 

[BLK HOLE]

are you the guy with the 4.88s?

No. 5.13s. Gas.

 

[Jefe1018]

I feel 3.73s are perfect for 37s!

She holds 8th empty in the rolling hills, tows a 4000lb travel trailer in 7th, and 6th towing in the hills. 25ish mpg unloaded in a 6400lb truck on 37s?

Why would a person mess with that?

You are still seeing 25mpgs on 37's? Sweet!

I would be happy to see mid to high teens flirting with 20mpg. All of my rigs before have gotten between 9-13 city and 12-16 highway with 31-33" tires. I'm not into this hobby for the mileage, but when going out further range does creep into the back of my mind.

 

[OnlyOne]

Zero reason to regear the diesel.

 

[CrazyCooter]

You are still seeing 25mpgs on 37's? Sweet!

I would be happy to see mid to high teens flirting with 20mpg. All of my rigs before have gotten between 9-13 city and 12-16 highway with 31-33" tires. I'm not into this hobby for the mileage, but when going out further range does creep into the back of my mind.

Yes, Ive had 37s since 27 miles on the clock.. I regularly see 25ish + or - on a highway trip on flatter terrain. Today on a road where the speed limit was 45mph she was showing 31 mpg for about 45 miles!

My YJ is 2500lb lighter and has smaller tires, but gets 10-14 mpg with the 4.0!

 

[Jefe1018]

Yes, Ive had 37s since 27 miles on the clock.. I regularly see 25ish + or - on a highway trip on flatter terrain. Today on a road where the speed limit was 45mph she was showing 31 mpg for about 45 miles!

My YJ is 2500lb lighter and has smaller tires, but gets 10-14 mpg with the 4.0!

Nice. My truck should be ready to pick up in the next two weeks, it’ll be on a 2 inch lift and 37’s. I am excited for the 650 miles home and now even more knowing fuel won’t be as bad.

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