Should I re-gear? And if so to what?

[Andrew Redbeard]

This has probably already been discussed and just never found the post, but I keep wondering if I should regear my Jeep. I’m a new Jeep owner, had it for almost a year, and I’ve been wondering if I should regear it and what that would do. It’s a 4.0 automatic and has 34-34.5 TOYO AT2s (they’re in metric and can’t think of the actual size). The previous owner lifted it 3” and put 35 MTs on but I don’t think he regeared it. I believe if I researched it right the stock gears are 3.55. It’s mainly a road driver but I do go on trails but nothing extreme like crawling over stuff.

So I’m wondering is a regear necessary and if so what should I regear to and what would I get out of it. A rough cost estimate wouldn’t hurt either.

 

[TJ Hunnicutt]

Short answer; YES!

OK, longer answer:
Even a manual transmission 4.0 TJ would need some serious regearing to run 34-35" tires, but a TJ with the automatic has a much greater need due to the very steep .65 to 1 overdrive gear ratio Jeep had in the 42RLE tranny.

Give me a minute and I can come up with a suggested gearing number...

 

[TJ Hunnicutt]

You would want to regear to 5.13 or 5.38. If you think you might want to do some serious or, even simi-serious, off roading or would consider 35-37" tires in the future, go with the 5.38. You may get slightly less mileage with the 34's but, maybe not. You are almost certainly getting crap mileage now on the highway.

And, hey, congratulations on your TJ and welcome to the forum!

 

[Andrew Redbeard]

Alright thanks. And ya the mileage isn’t too great. I think I’m getting maybe around 11 but I haven’t actually driven, filled up and calculated. What all would I get out of regearing and would you know maybe an estimated cost of regearing?

 

[TJ Hunnicutt]

You will feel more power and pep for sure. You should also see an increase in highway mileage; maybe even in city driving since your Jeep is currently so very under geared.

As for price, I'd hate to say, for two reasons; 1) I do all my own wrenching, so I have not looked into it and 2) it really depends on where you go. My advice is to call around to every place you can find. Don't forget the dedicated 4x4 shops as they can sometimes be quite a bit cheaper...but can also be major rip-off palaces. Like I said, call around.
Here's a recent thread that mentions prices.

Also, consider getting the gears yourself and taking them in to the shop. That way, you don't have to pay their parts mark-up and you know what quality gears you're getting.

Good luck, but I know you will enjoy your ride much better when you have some proper gearing in place!

 

[Andrew Redbeard]

Alright sweet. Thanks for the advice!

 

[jazngab]

From my price shopping experience shops charge approx $1k per axle for regear. At least here in the NE region.

 

[JMT]

Regearing will restore on and off-road performance. You likely don’t know how much performance you’ve lost since the previous owner had 35’s already on it. You’ll have power. The proper gear ratio for 35’s, 42rle, and the 4.0 would be 5.38.

Best to NOT supply your own gears since a shop won’t warranty the gears. If something goes wrong they’ll blame the gears you provided and you’ll be screwed. The labor in TX is $500/axle.

What rear axle do you have? Running metric 34’s is pushing the limits of the Dana 35, even on the streets.

 

[Pacoson71]

5.13 is all you can get unless you have Dana 44 front and rear. Assuming with your 3.55s you don't.
I priced out 5 places local here in MA, dropped the high and two of the low. just under 2k inclusive parts and labor.
for both axles on a Rubicon.
He lists 2200 for regears mainly because you will need to upgrade your carriers to allow for the gear change.

I'm waiting for my 5.38 gears to come and have read I'll be looking at 13+ MPG switching to my new 5.38s .

 

[DrDmoney]

Redbeard has a 2002 it came with a 32RH 3 Speed with a final drive ratio of 1:1

 

[DrDmoney]

4.56:1 on the left 4:10 on the right

 

[DrDmoney]

Dana 35’s were standard with a 3.07 or 3.73 ratio, if the PO had regeared it to 3.55, it must have been a 3.07 Dana 35. Dana 44’s came with 4.10.
Like @JMT said its pushing it with a Dana 35.

 

[Andrew Redbeard]

Ok so if it’s pushing it with the Dana 35 should I look at building up my rear axle to handle the 34s?

 

[Rob5589]

4.56 with your combo. For the 35 to live with 35's you can go two ways. If mild to moderate trails; 27 spline 1541H axles and a Truetrac. If more hardcore; a full Super 35 (30 spline axles) and a locker of some sort, Detroit/ARB/E-Locker.

 

[Andrew Redbeard]

4.56 with your combo. For the 35 to live with 35's you can go two ways. If mild to moderate trails; 27 spline 1541H axles and a Truetrac. If more hardcore; a full Super 35 (30 spline axles) and a locker of some sort, Detroit/ARB/E-Locker.

So what I’m doing is mainly street driving and mild trails every once in a while when I have time to just drive and explore.

 

[Jerry Bransford]

This has probably already been discussed and just never found the post, but I keep wondering if I should regear my Jeep. I’m a new Jeep owner, had it for almost a year, and I’ve been wondering if I should regear it and what that would do. It’s a 4.0 automatic and has 34-34.5 TOYO AT2s (they’re in metric and can’t think of the actual size). The previous owner lifted it 3” and put 35 MTs on but I don’t think he regeared it. I believe if I researched it right the stock gears are 3.55. It’s mainly a road driver but I do go on trails but nothing extreme like crawling over stuff.

So I’m wondering is a regear necessary and if so what should I regear to and what would I get out of it. A rough cost estimate wouldn’t hurt either.

34.5" is commonly referred to as a 35" tire which is pretty much above the strength limit of your Dana 35. 33" is the commonly accepted upper size limit for a Dana 35 axle. Just be very easy on the gas, getting on it too hard can result in a broken axle shaft like below, this happened to a friend of mine while we were on a trail... I heard it snap. If you want you can strengthen your axle with stronger replacement axle shafts, or next time you buy tires go with nothing larger than 33".

With your 3-speed automatic, regearing to 4.56 would be appropriate for your 35" tires, 4.10 would be the correct choice for 33" tires. Costs to regear both axles including parts & labor is anywhere from $1300 to $1800 depending on the shop and how good you are at pushing for discounts. Regearing would be the perfect time to replace the axle shafts with something stronger if you want to stay with your current tire size.

Dana 35’s were standard with a 3.07 or 3.73 ratio, if the PO had regeared it to 3.55, it must have been a 3.07 Dana 35. Dana 44’s came with 4.10.

1997 Wranglers with the 4.0 engine came with a 3.07 or 3.55 ratio. 3.73 didn't come along until 1998. All Dana 44 axles in the standard Wranglers came with 3.73, only the Rubicon Dana 44 axles came with 4.10 gears.

 

[DrDmoney]

1997 Wranglers came with a 3.07 or 3.55 ratio. 3.73 didn't come along until 1998. All Dana 44 axles in the standard Wranglers came with 3.73, only the Rubicon Dana 44 axles came with 4.10 gears.

That’s not entirely true, there was a time l call it “BR” Before Rubicon, the Sahara’s had 44’s and Sports could be ordered with them too. Mine is a 2000 Sport optioned with a 4:10 44.

 

[Rob5589]

So what I’m doing is mainly street driving and mild trails every once in a while when I have time to just drive and explore.

For that usage, my first suggestion.

 

[Jerry Bransford]

That’s not entirely true, there was a time l call it “BR” Before Rubicon, the Sahara’s had 44’s and Sports could be ordered with them too. Mine is a 2000 Sport optioned with a 4:10 44.

I've never heard of a 2000 Wrangler Dana 44 coming from the factory with anything but a 3.73 ratio. The Dana 44 was never standard with the Sahara, it was always strictly an option for the Sahara as it was with the Sport.

 

[Andrew Redbeard]

Do you sudjest any specific manufacturer/brand to go with for the axles and gears?