"Do I REALLY need to re-gear for 37s?" - Yes. Yes you do.

[CJ5w4wdSmokyOnMyTail]

Well, no you don't HAVE to re-gear when adding 37" tires to a 3.6 automatic JT, but you will want to. After 3.5 years on 35" Toyo AT IIIs, I switched to 37" Yokahama Geolander ATXs when Walmart forced me to with an unbelievably great deal. The 4:10 gear-ratio Jeep Mojave looks great and drives great on the 37s, but there is a noticeable lack of pep in the step now. The JT is a bit more sluggish off the start. I love the new stance and added clearance but will definitely be re-gearing to 4:88 to recover the lost pop and turn those larger tires.

Sponsored

 

[Duece McCracken]

Geez, my Manual trans JTR on OEM 33" is slow as molasses. I couldnt imagine 37". Im probably going 5.38 to regain what I'd lose, and then get some extra rev into it. The 3.6 is quite gutless. Not that I've had anything else in the jeep line besides a couple 4.0 XJ's.

 

[DailyMoparGuy]

As someone that just switched from 35s to 37s, I can comfortably say I’ll be regearing for sure. The truck on 35s was at home with 4.10s for street driving imo.

It’s more sluggish with 37s sure but I kinda like it for some odd reason…makes it feel like an old truck. I haven’t done too much highway driving but I barely saw 8th in the little I did. This wasn’t the case on my old 35s.

If I lived somewhere flat like Florida, SE Texas, etc, then I probably wouldn’t regear.

The real question is should I go 4.88 or 5.13…just kidding everyone, I’ll use the search tool

(probably going 5.13s)

edit: after more research, 4.88 might be the move for me. Hard to say though as I keep adding weight to this thing. I spend a LOT of time on the highway and from what I gathered, 4.88 will be better for that application. Not in a rush, so I’ll keep researching in the meantime

 

[CJ5w4wdSmokyOnMyTail]

Geez, my Manual trans JTR on OEM 33" is slow as molasses. I couldnt imagine 37". Im probably going 5.38 to regain what I'd lose, and then get some extra rev into it. The 3.6 is quite gutless. Not that I've had anything else in the jeep line besides a couple 4.0 XJ's.

I hear the 3.6 auto is more accommodating than the manual. On the 35"s, the 3.6 auto was totally fine and peppy enough for me.

 

[Duece McCracken]

I hear the 3.6 auto is more accommodating than the manual. On the 35"s, the 3.6 auto was totally fine and peppy enough for me.

Yeah, autotradgic copes with it decently, so people say. Which is why I made sure to state my opinion with my transmission type, lol

Diesels though, they apparently dont give a flying F about 37's, lol

 

[chr15m]

My JTM with the auto, 4.10s and 35" tires feels better than my Tacomas did with 33s, that's including the MT with 4.30s. Its really still a subjective decision.

I felt more of a change switching to 35s on my 5.7 Tundra than I did on the Jeep. Having said that, no amount of gearing advantage would give me the pep the Tundra had despite the noticeable change. I think the 850RE does a great job, I still routinely see 8th and can get 20mpg on highway trips, city is pretty much locked at 17 hand calculated. My Tacomas never peaked above 17, even stock.

If I go 37s I certainly wait to see about regearing, because as it is, its hard to imagine another 4% or 5% larger tire would make it as sluggish as those Tacomas. If its even slightly better than they were I'm good.

As long as the choice you make, makes you happy then that's a win.

 

[antwon412]

I don’t feel much difference between the 4.10 with the 35s or 37s and 5.13 and 35s and 37s myself.

 

[Bjeepz]

The difference in my Mojave from 35 to 37 is noticeable in acceleration, braking and cornering. I run light Cooper AT3 XLT's. Will I re-gear, nope, never for 37's as the mileage is still fine and the cost will never offset that difference. As for performance sure 4.88's would be sweet, but I am fine as is. I still pull out from a dig with stock Tacoma's, never mind when the kids run big fat 33's lol.

 

[Pliny]

It really depends on your starting gear ratio and how you use your Gladiator. Having 3.73 instead of 4.10 would make it more likely that you'd want to regear. If my JTR with 4.10 and 37's lived it's life down in Phoenix, at an elevation of 1200 feet, and never towed, then I probably wouldn't have regeared. Since my JTR is at our cabin at 6600 feet of elevation (where the normally aspirated 3.6L is down 20% in HP due to lower air density) and it's purpose in life is to tow our 3000 lb. trailer, I had it regeared with 5.13s.

 

[CJ5w4wdSmokyOnMyTail]

The difference in my Mojave from 35 to 37 is noticeable in acceleration, braking and cornering. I run light Cooper AT3 XLT's. Will I re-gear, nope, never for 37's as the mileage is still fine and the cost will never offset that difference. As for performance sure 4.88's would be sweet, but I am fine as is. I still pull out from a dig with stock Tacoma's, never mind when the kids run big fat 33's lol.

I would have preferred lighter tires. The Geolanders are kinda mid-range in weight for 37s but the deal was really good ($270 per tire). I wouldn't regear to get better gas mileage because you are probably right about never recouping the cost. I just want the pop back and have 37s. But the cost to regear will delay that upgrade until I can save up the cash.

 

[EddyArnold]

3.73 and chirpn' tires on 37's!

#diesel

 

[Camaroboi13]

Diesels though, they apparently dont give a flying F about 37's, lol

Truer words were never spoken!

I’m thinking 38s next time around or maybe some all terrain 40s

 

[Panthers65]

go 5.13's you won't be sorry

 

[RudeJeepin]

Diesels though, they apparently dont give a flying F about 37's, lol

I just went from the OE 285/70r17s to 315/70r17 and I notice the difference with my JTRD. Probably not gonna regear yet. But I if/when I go 37s, a regear will probably be included.
Wish somebody made a solid 4.37 gear set. Personally, I think that would be the sweet spot for my Gladiator diesel and my use.

 

[Koolcarguy]

Well, no you don't HAVE to re-gear when adding 37" tires to a 3.6 automatic JT, but you will want to. After 3.5 years on 35" Toyo AT IIIs, I switched to 37" Yokahama Geolander ATXs when Walmart forced me to with an unbelievably great deal. The 4:10 gear-ratio Jeep Mojave looks great and drives great on the 37s, but there is a noticeable lack of pep in the step now. The JT is a bit more sluggish off the start. I love the new stance and added clearance but will definitely be re-gearing to 4:88 to recover the lost pop and turn those larger tires.

If running a 3.6 I'd say yes definitely research. My diesel could care less my brother runs 40's on his diesel no research and no complaints. My jk with 35 and 4.88 is barely enough lol

Sponsored