6-speed with 37’s (how bad for a few months?) Update: now with 39's!

[Some Random Guy]

I’m starting to shop around for quotes to regear to 5.13. Right now I’ve got a $2600 but can’t book until July and a $3500 that might be right away. I’m talking to the $3500 to see what is included (500 flush, backlash reset if it whines).
My question is, how bad are 37’s on the M/T with stock Rubicon gearing? I’ve never really believed anyone who said they were fine. That’s a lot of extra rotational inertia. Do I need to slip a lot more to get going, or is it barely noticeable? Luckily my commute is short and I can ride with my wife a lot to work, she’s in the same building.

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[grimmjeeper]

It wouldn't be ideal, that's for sure. But after having a stock JK with the 3.6/6 speed and 32" tires with 3.21 gears, I would say you can live with it for a little while.

The JL has a better first gear than the JK I had. Along with the 4.10 gears, you're at a better ratio than I was stock at the time.

But yeah, you'll want the 5.13s.

 

[Some Random Guy]

It wouldn't be ideal, that's for sure. But after having a stock JK with the 3.6/6 speed and 32" tires with 3.21 gears, I would say you can live with it for a little while.

The JL has a better first gear than the JK I had. Along with the 4.10 gears, you're at a better ratio than I was stock at the time.

But yeah, you'll want the 5.13s.

Thanks, I live on a hill and have a couple steep launches on my commute. I might be able to sit on my lift/tires until after I get the regear done, but I think Maximus-3 anticipates having it shipped at the end of the week. It will drive me crazy walking past it, plus I have about 2 weeks of vacation to burn in July.

 

[grimmjeeper]

Thanks, I live on a hill and have a couple steep launches on my commute. I might be able to sit on my lift/tires until after I get the regear done, but I think Maximus-3 anticipates having it shipped at the end of the week. It will drive me crazy walking past it, plus I have about 2 weeks of vacation to burn in July.

Yeah, I waited to build up the cash to do the upgrade to 4.56's and 35" tires all at once myself. And after driving it, I wish I would have gone with 4.88s. Still, it was night and day better when I was all done. But I drove it with stock 32" tires and 3.21 gears for a year. Off road it was not great. And I didn't use overdrive unless I was going downhill. But if you're doing the gears "soon", you'll be able to live with it for a little while.

 

[word302]

I’m starting to shop around for quotes to regear to 5.13. Right now I’ve got a $2600 but can’t book until July and a $3500 that might be right away. I’m talking to the $3500 to see what is included (500 flush, backlash reset if it whines).
My question is, how bad are 37’s on the M/T with stock Rubicon gearing? I’ve never really believed anyone who said they were fine. That’s a lot of extra rotational inertia. Do I need to slip a lot more to get going, or is it barely noticeable? Luckily my commute is short and I can ride with my wife a lot to work, she’s in the same building.

I ran for 2 1/2 years with my manual JLUR and 37s. It drives fine, wheeled it plenty like that too. You'll love the 5.13s once you get them but it's not a huge deal. Clutch difference isn't really noticeable. I live in the NW where it's pretty hilly and I was able to live with it, though it's sooooo much better now.

 

[Some Random Guy]

I ran for 2 1/2 years with my manual JLUR and 37s. It drives fine, wheeled it plenty like that too. You'll love the 5.13s once you get them but it's not a huge deal. Clutch difference isn't really noticeable. I live in the NW where it's pretty hilly and I was able to live with it, though it's sooooo much better now.

I’m in Washington, so that’s really helpful. I might stick with the lower cost and suck it up for a month. Time to go read some reviews to make sure they’re not lying when they say they don’t have complaints.

 

[word302]

I’m in Washington, so that’s really helpful. I might stick with the lower cost and suck it up for a month. Time to go read some reviews to make sure they’re not lying when they say they don’t have complaints.

Yeah I bought a press and just did the gears myself. Heard too many horror stories and I really don't like anyone else touching my vehicles if I can help it. I have an extra vehicle so I was able to take my time and do it over the course of a week. Job wasn't too bad, just need high attention to detail and the right tools.

 

[grimmjeeper]

Yeah I bought a press and just did the gears myself. Heard too many horror stories and I really don't like anyone else touching my vehicles if I can help it. I have an extra vehicle so I was able to take my time and do it over the course of a week. Job wasn't too bad, just need high attention to detail and the right tools.

Yeah, I've done half a dozen axles so far and I have half a dozen lined up for my projects and with friends.

It's tedious work. But it's nice knowing it was done right and not rushed.

Besides, I lost a set of gears when the installer didn't use locktite and the ring gear bolts backed out. So I have a trust issue with shops now...

 

[Some Random Guy]

I work in a office, at a desk, on a computer. So I’m a little gun shy doing gears myself. Axle shafts, sure. But when you start talking about hundredth’s or thousandth’s of an inch causing loud whines, I’m not so sure. I plan to learn in a few years when I have a different winter commuter, but not this time.

 

[beast40]

Its not bad at all. I have 1500 miles including a 700 mile round trip on my 37s with stock gearing.

I was set on re-gearing right away but now I'm going to wait.

 

[grimmjeeper]

I work in a office, at a desk, on a computer. So I’m a little gun shy doing gears myself. Axle shafts, sure. But when you start talking about hundredth’s or thousandth’s of an inch causing loud whines, I’m not so sure. I plan to learn in a few years when I have a different winter commuter, but not this time.

Tolerances are measured in thousandths of an inch. And it ends up being easy to adjust once you get in and do it.

I drive a desk for a living too. But my hobby is working on vehicles and I've learned a lot over the last several decades and have built up quite a shop. So I have all of the expensive tools needed to do a gear change. Shop press, rotational torque gauge, dial gauge, digital caliper, case spreader, etc.

Anyone who can tell which type of screwdriver is which can learn to do gears. But I wouldn't just jump right in and try it without some training and coaching.

Best bet for most people is to find a good reputable shop. The shop that set up my gears was cheaper and I didn't look into their reputation. My bad.

The good shop (should be at least a few in WA) will be able to get all the right parts and they will have someone who knows what they are doing. They will get good quality parts and give you a parts and labor warranty. And they will cost less than having to go and buy all the tools yourself.

If you really want to learn to do it, absolutely find someone local to help you and dive in. But there's nothing wrong with just giving someone money and having them do it if you're not really excited about doing it yourself. Probably over 90% of the people out there just take it to a shop. It's just us crazy people who take DIY that far.

 

[beast40]

I helped set up gears one time and that was plenty. It was on a HPD30 swap with 4.88s. Its a bitch of a job, takes countless time and to do right you need to spend a lot in tools. I love working on my Jeep but unless you plan on doing numerous gear set-ups the juice isn't worth the squeeze.

 

[grimmjeeper]

I've been thinking about going the other way. I want to add a pinion depth gauge to my set of tools so I can do it faster. I have at least half a dozen axles to do between a buddy and myself. And maybe another set or two out there. And that's just within the next year.

 

[word302]

I've been thinking about going the other way. I want to add a pinion depth gauge to my set of tools so I can do it faster. I have at least half a dozen axles to do between a buddy and myself. And maybe another set or two out there. And that's just within the next year.

All the pros I have talked too say the depth gauge is pretty much worthless. Even if you're setting up a bare axle there's plenty of good info out there about a good starting point.

 

[word302]

I helped set up gears one time and that was plenty. It was on a HPD30 swap with 4.88s. Its a bitch of a job, takes countless time and to do right you need to spend a lot in tools. I love working on my Jeep but unless you plan on doing numerous gear set-ups the juice isn't worth the squeeze.

Meh, if you're mechanically inclined it's really not that bad of a job if you use quality parts. The Dana gearsets almost fall into place with very little adjustment. The only expensive tool is a press, which really isn't that expensive and you'll find tons of uses for it once you have one.

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