Best gears for regearing

[whiteglad]

I suggest that you compare the true running diameters of the tires, not just the advertised sizes. Some 37s are more like 36's, etc. Also some tires and wheels are much heavier than others, affecting inertial resistance.

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[Gshane]

I suggest that you compare the true running diameters of the tires, not just the advertised sizes. Some 37s are more like 36's, etc. Also some tires and wheels are much heavier than others, affecting inertial resistance.

Thx. I have 37 inch Katanis to put on. They weigh 72lbs which is what my present 35s weigh. And their smaller 37s so I'm hoping I'll be good with just the Mopar lift on my Sport. There's a lot of room right now with Wildpeak at 35s. If I need to I'll add a 3/4 inch front spacer. Thx!

 

[Gshane]

Dana is far and away the best for the advantek axles. Yukon has a bit of a bad reputation in the advantek axles, revolution and nitro are decent but if you can get Dana go Dana.

Also may I recommend 5.13s for 37s, there is only a small difference at highway speed compared to 4.88 thanks to the 2 overdrives on the 8 speed but a better first gear and if you want to go with heavier rims or tires or 38s or even 39s you'll be glad you went 5.13s.

Thx!

 

[Gshane]

I am lucky enough to have a trusted shop in my area, TORC motorsports, who specialize in re-gearing Jeeps. Even though your shop might be a few hours away, definitely worth the drive to have it done right. Since the work will likely take a few days, I’d make the drive and just drop it off. Admittedly that’s not the easiest thing to do, but worth it in the long run. I’ve had my 5.38’s for about 8k miles and have had zero problems and tons of fun. My truck on 37’s is snappier than a stock Mojave.

Thx. Yeah I agree. After digging into this and hearing from some of you I'm just gonna make the drive and get it done right. I was thinking 4.88 but now I'm leaning 5.13. Thx

 

[Gshane]

5.13's and BFG 37s here (Small 37s) and I'm real happy I didn't do 4.88s. My last take of gas mix city and high was 18.3 mpgs and towing my boat is way more comfortable than the old 4.10s.

I went with spicer gears too, a light hub on acceleration, but it's nothing compared to the tires.

And I definitely wouldn't have a dealership do this. Even if they say they will the gears are aftermarket, not a factory/warranty part. Ask your local off-roading groups or local car groups for recommendations on gear installers. Plenty of local shops around that know what they are doing. Not a general maintenance garage but an aftermarket shop.

Yeah - after digging into this and hearing from some of you I've decided to just make the drive and get it done right by a shop I can trust. Thx!

 

[Main Line Willys]

I would not rule out a local transmission shop. I have had multiple vehicles regeared over the years, but 1 time I was in a bind with a blown rear on my F350. The local transmission shop was able to get me in right away and at very reasonable price.

Dealership would be the last place I look.

 

[msatts]

I just got Revolution 5.13s installed late August and have had a great experience so far. Dana first, Revolution second in my opinion I would stray away from Yukon.

 

[Gshane]

I just got Revolution 5.13s installed late August and have had a great experience so far. Dana first, Revolution second in my opinion I would stray away from Yukon.

Thx!

 

[Deleted member 58561]

Can someone tell me about what is a fair price for regearing? I’m thinking 4.88 for my needs. I’ll have to coordinate a bunch of stuff though. Suspension, tires, gearing. $$$

 

[Gshane]

Can someone tell me about what is a fair price for regearing? I’m thinking 4.88 for my needs. I’ll have to coordinate a bunch of stuff though. Suspension, tires, gearing. $$$

As I'm calling around I'm hearing anywhere from $1800 to $2500 for 4.88 or 5.13.

The Mopar 2 inch lift I have was around $1800 installed.

35 or 37 inch tires with after market rims with the proper offset vary greatly in price, but the package of wheels and tires could be anywhere from 2-3k...

I just ordered 4 37 inch Katani Trail Hogs from Priority Tire for $1,100 delivered to my house. I need to have em mounted and balanced but they were close to half the price of the big brand names. I know it's a bit of a risk but they have a lot of great reviews so I thought I'd give em a shot to save a thousand bucks.

Hope that helps you a bit.

 

[rharr]

clearly these should be your go to for your jeep chevrolet
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[1550jrit]

I just finished a 1300 mile trip to Black Hills, SD for a Jeep Jamboree. The truck ran great with 5.38’s both on and off road. MPG’s suffered going across SD where the speed limit is 80mph. I averaged about 13.5mpg’s loaded down and holding the speed limit. There’s no escaping the aerodynamic limits of these trucks. If I dropped to 70mph my fuel economy jumped by almost 2mpg.

Off-road I had plenty of power pushing 37’s that were aired down to 16psi. The funny part is that when I used my off-road cruise control, more often than not the transmission selected 8th gear for crawling down the trail. The 5.38’s paired well with my Mojave’s 2.72 transfer case as manually holding 1st gear in 4lo is a super slow crawl speed. Obviously not as low as a Rubicon, but good enough for what I want to do with the truck.

Someone had previously asked in another thread about differential temps when running 5.38’s. The question came up as to whether the diffs would run hot with such deep gearing. I drove straight through from the Black Hills to Omaha with only two quick stops for fuel, about 650 miles, averaging 75-80mph the entire time. As soon as I pulled into my driveway I grabbed my IR thermometer and checked the rear diff temp, which was 151 degrees. This did not seem extra ordinarily high to me, but I also don’t know what a typical diff temp should run. I did install the Dana nodular iron covers (during my re-gear) which have built-in cooling fins, so I’m sure that helps a bit.

 

[JTR2021]

DANA is what's in there now and a good company.

Yukon has a good reputation, but also has a reputation for being noisy.

I know nothing of Revolution.

Thx. Yeah I agree. After digging into this and hearing from some of you I'm just gonna make the drive and get it done right. I was thinking 4.88 but now I'm leaning 5.13. Thx

Here’s some advice from real world experience on re-regearing in general. Yes tire size and weight matter, but so does added vehicle accessories ie bumpers, racks, gear in the bed etc. I would a very good idea on what the finished build was going to look like before selecting a gear ratio. Also the terrain you mostly drive on is a factor. Most of us use our rigs as daily drivers so that also needs to be part of the equation. Do you plan on towing as well. I have a 21 JT Rubicon on 38 Nitto Trail Grapplers, with a Rebel 1/2 rack, 23 Zero Armadillo tent, aftermarket bumper, 12000lb winch plus APL 55 fridge, Rotopax and 165 liter hard case full of camping gear in the bed. Re-gearing was the last mod and only after driving several hundred miles and monitoring the transmission gearing. I found at highway speeds I was mostly in 7th and occasionally in 8th if I was going downhill. I ended up going with Spicer 4.88s on the recommendation of the shop doing the install. I couldn’t be happier. I struggled with dilemma of 4.88 vs 5.13 for days before pulling the trigger. Even given the weight I’m pushing, the 4.88s were the right choice for my rig. I occasionally tow a Smittybilt Scout trailer ( where the RTT will eventually go) and their has been no let down even pulling fairly steep hills at highway speeds. Off-road is no issue with the 4 to 1 transfer case. I guess the moral of the story here is, go with Dana Spicer gears and a 5.13 ratio is probably overkill.

 

[Gshane]

Here’s some advice from real world experience on re-regearing in general. Yes tire size and weight matter, but so does added vehicle accessories ie bumpers, racks, gear in the bed etc. I would a very good idea on what the finished build was going to look like before selecting a gear ratio. Also the terrain you mostly drive on is a factor. Most of us use our rigs as daily drivers so that also needs to be part of the equation. Do you plan on towing as well. I have a 21 JT Rubicon on 38 Nitto Trail Grapplers, with a Rebel 1/2 rack, 23 Zero Armadillo tent, aftermarket bumper, 12000lb winch plus APL 55 fridge, Rotopax and 165 liter hard case full of camping gear in the bed. Re-gearing was the last mod and only after driving several hundred miles and monitoring the transmission gearing. I found at highway speeds I was mostly in 7th and occasionally in 8th if I was going downhill. I ended up going with Spicer 4.88s on the recommendation of the shop doing the install. I couldn’t be happier. I struggled with dilemma of 4.88 vs 5.13 for days before pulling the trigger. Even given the weight I’m pushing, the 4.88s were the right choice for my rig. I occasionally tow a Smittybilt Scout trailer ( where the RTT will eventually go) and their has been no let down even pulling fairly steep hills at highway speeds. Off-road is no issue with the 4 to 1 transfer case. I guess the moral of the story here is, go with Dana Spicer gears and a 5.13 ratio is probably overkill.

Thx! That's great to hear. The guy that's gonna do the work basically told me all that the last time we spoke so I decided on the Dana Spicer 4.88s. They have been ordered and will be installed in a couple weeks. Thx again for the real world info! Much appreciated.

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