3.73 gearing with 37s

[Geekjeep]

This was my set up. I have a sport s and put 37s. I live at sea level. And it was adequate. Just less fun to drive. It never felt underpowered. The reason I did the gears was it made the driving experience fun again. Feels like a different motor. It was $2600 for a ton of fun.

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[Schleg]

I decided to go to 35s with my 3.73 gearing. If I am easy on the acceleration I can get close to 19mpg, but driving like I want to, and reminding myself often that the acceleration is still not bad for a Jeep, I hover around 17mpg. The other thing is with a 3.5 inch lift and 35s, I can't imagine loving the look any more than I do now. I'm very happy with my decision.

 

[Binford]

Okay everyone, I've scanned a lot trying to gather information on this topic from various places on the forum. I want to just hear from people with experience running 37s with 3.73 gearing on their JT, including their perception of their performance, how long they've been running that setup, and if they made any other mods. Thanks!

I had 35's on 3.73 and it drove like shit... Regeared to 4.56 and it drives MUCH better. I wouldnt even wanna try 37's on 3.73

 

[Sno4Me]

I had 35's on 3.73 and it drove like shit... Regeared to 4.56 and it drives MUCH better. I wouldnt even wanna try 37's on 3.73

Well I had mine re-geared to 4.56 and very happy..

Cheers All !!

 

[Deleted member 30519]

Well I had mine re-geared to 4.56 and very happy..

Cheers All !!

I'm running 38s on 3.73 gears with a M/T. I'm not having any issues with it being slower but I noticed I need to use 2nd longer 3500-4k rpm and then when I'm in 3rd on back curvy roads I feel like I can only maintain 3rd @ 2k rpm going 35-40 mph with the limited speed limit. I really wanna find the courage to push 2nd harder but I don't really go passed 4k rpm. I'm probably going to re gear when my warranty is up.

 

[tfranks]

Well I had mine re-geared to 4.56 and very happy..

Cheers All !!

What ballpark does a re-gearing cost?

 

[FLUndertaker]

My 5.13 with a pedal commander makes mine snappy as hell. Love it and actually had to tune the PC down to Sport 2.

 

[hjdca]

My 5.13 with a pedal commander makes mine snappy as hell. Love it and actually had to tune the PC down to Sport 2.

Yes, this is what people forget. With 5:13s, you are basically getting 2 more lower gears for 1/4 mile acceleration, and your 2 overdrive gears are now useful at high speed and minor hills. I was shocked how much more torque and power I have now with 5:13s and 37s. Out of the hole, the truck is really quick now - I surprise a lot of people with my six speed manual.

 

[AZCooWhip]

I had 35's on 3.73 and it drove like shit... Regeared to 4.56 and it drives MUCH better. I wouldnt even wanna try 37's on 3.73

This. All. Day. Long. You won’t regret the investment.

 

[Deleted member 28696]

I have 37's on 4.10 stock Rubicon gears it's ok but there were a few times that it kept wanting to rev the engine especially when trying to get going in a hurry. I do have it reprogrammed for 37" tires now (actual size is 36") I am regearing to 5.13 here in the next month when I do my 3" lift. I don't feel that 4.10's are enough, I think 4.88's get you back to stock with 37" and 5.13 is extra assurance. but 3.73 I doubt would be enough. it comes with 4.10's and 33" tires so you would have to gear higher even with 35" tires I would think. I believe 4.10's would probably work but anything lower I doubt would be too good. I'm also running 20" Rims so that will add some extra weight compared to 17" wheels. I'm getting just shy of 15 mpg but I'm at 5280 feet.

 

[FLUndertaker]

I have 37's on 4.10 stock Rubicon gears it's ok but there were a few times that it kept wanting to rev the engine especially when trying to get going in a hurry. I do have it reprogrammed for 37" tires now (actual size is 36") I am regearing to 5.13 here in the next month when I do my 3" lift. I don't feel that 4.10's are enough, I think 4.88's get you back to stock with 37" and 5.13 is extra assurance. but 3.73 I doubt would be enough. it comes with 4.10's and 33" tires so you would have to gear higher even with 35" tires I would think. I believe 4.10's would probably work but anything lower I doubt would be too good. I'm also running 20" Rims so that will add some extra weight compared to 17" wheels. I'm getting just shy of 15 mpg but I'm at 5280 feet.

i did 5.13 with my 37’s and it’s night and day. I came from 4.10 and they were horrible with the 37’s and I’m at 1200’. Mile hi would be aweful! Anyone who says 3.73 are OK with 37s are either in complete denial or cannot read a tire size. I just added a pedal commander and it woke my JT up even more. It will move out from a stop light with supriding speed and I have it set to Sport 2. The more aggressive settings had me chirping tires.

 

[Deleted member 28696]

i did 5.13 with my 37’s and it’s night and day. I came from 4.10 and they were horrible with the 37’s and I’m at 1200’. Mile hi would be aweful! Anyone who says 3.73 are OK with 37s are either in complete denial or cannot read a tire size. I just added a pedal commander and it woke my JT up even more. It will move out from a stop light with supriding speed and I have it set to Sport 2. The more aggressive settings had me chirping tires.

I was looking at the Pedal commander product on you tube. I may consider it further for some added pep, thanks for reminding me. I agree after having 37's on 4.10's he wouldn't be happy with 3.73's at all. The 5.13's are what Trail Jeeps recommended for 37's and they seem to know what they are doing. We will see after next month, your commends kind of confirm that I'll be happy with it.

 

[Fastwake]

I have a 2020 Sport S 2” Mopar lift 12.50 x35 toyo tires. It has 3.73 gears. I have put 10k miles on it last year. Travel to Moab Utah, Nevada,Arizona and back to California. 8th gear comes and goes on the freeway but at 75mph I am only turning around 2200 Rpm in 7th gear I have plenty of power off the line (I am 68) and have no complaints with performance. Jeep trucks are not a race car so I am very satisfied with what it does. Of course regearing would be better but who cars. It I want to haul assi will drive my 427 Shelby Cobra. I have spoke to several Jeep mechanics and they all said JUST LEAVE IT ALONE.

 

[guarnibl]

I have a 2020 Sport S 2” Mopar lift 12.50 x35 toyo tires. It has 3.73 gears. I have put 10k miles on it last year. Travel to Moab Utah, Nevada,Arizona and back to California. 8th gear comes and goes on the freeway but at 75mph I am only turning around 2200 Rpm in 7th gear I have plenty of power off the line (I am 68) and have no complaints with performance. Jeep trucks are not a race car so I am very satisfied with what it does. Of course regearing would be better but who cars. It I want to haul assi will drive my 427 Shelby Cobra. I have spoke to several Jeep mechanics and they all said JUST LEAVE IT ALONE.

It really depends on what motor you have. From my experience, the 2.0L/3.6 was just fine with light 37's on stock wheels with spacers. I.e., KO2's. However, when I ran my Nitto's on beadlocks, good lord, it was awful with the 2.0. I mean freeway speeds I was under 10 mpg, and it just became annoying. Literally never saw 8th gear on freeway, rarely saw 7th since I was using the pedal constantly. If it was flat... I guess it was OK, but as soon as there was elevation and/or wind, it was an issue.

Glad I have the diesel now, as it doesn't give a shit what tires I have with 3.73's (i.e., beadlocks + 40's netted 23 mpg).

I still agree though, I wouldn't have re-geared if I would have kept the JLUR. I probably just would have run 37 KO2's daily like I do now, and swapped for wheeling trips and dealt with it. With stock wheels and 37 KO2's I was still able to do 65-70 and get 14-15 mpg.

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