Rear diff 4.10 gearing

psinsyd · **Posted:** Sun Dec 03, 2006 4:37 pm

Hey everyone,

Seems like a decent price. Is this the correct setup for redoing the gearing in the rear on the KJ? Any experience with this brand?

Thanks!!

http://cgi.ebay.com/ebaymotors/Dodge-Da ... dZViewItem

elephantrider · **Posted:** Sun Dec 03, 2006 5:46 pm

this would give you more low end go, correct?

4.10 gears would make that much difference?

unixxx · **Posted:** Sun Dec 03, 2006 6:42 pm

I've heard that Motive Gear is a good brand. Yukon Gear is good too and supposedly US Gear is the best. Just make sure you stay away from Genuine Gear. Regearing from 3.73 to 4.10 should offset the losses from 245 tires well.

psinsyd · **Posted:** Sun Dec 03, 2006 7:05 pm

unixxx wrote:

I've heard that Motive Gear is a good brand. Yukon Gear is good too and supposedly US Gear is the best. Just make sure you stay away from Genuine Gear. Regearing from 3.73 to 4.10 should offset the losses from 245 tires well.

Thanks unixxx. That's exactly what I was looking to do, to offset the loss for the 245's. The gears are the correct model, right? The Chrysler 8.25 rear end.

OzLtd · **Posted:** Sun Dec 03, 2006 7:16 pm

psinsyd wrote:

unixxx wrote:

I've heard that Motive Gear is a good brand. Yukon Gear is good too and supposedly US Gear is the best. Just make sure you stay away from Genuine Gear. Regearing from 3.73 to 4.10 should offset the losses from 245 tires well.

Thanks unixxx. That's exactly what I was looking to do, to offset the loss for the 245's. The gears are the correct model, right? The Chrysler 8.25 rear end.

I believe they are correct, however I cant help but think about wether the axles are the same or not ? Not sure if this would make any difference to the diff's internals ? Make a call and find out from a proper diff shop.

Rock Lizard · **Posted:** Sun Dec 03, 2006 8:59 pm

I wouldn't buy gears off ebay, and I'm not real knowledgeable on axles and gearing. but the 8.25 for the KJ is a 29 spline, those are for a 27 spline, which was in the dakotas and pre 97 Cherokees. I'm just not for sure on if a 27 spline gear will work on a 29 spline carrier. I would call Quinn at AllJ and find out the right gears for the KJ.

psinsyd · **Posted:** Sun Dec 03, 2006 9:04 pm

Rock Lizard wrote:

I wouldn't buy gears off ebay, and I'm not real knowledgeable on axles and gearing. but the 8.25 for the KJ is a 29 spline, those are for a 27 spline, which was in the dakotas and pre 97 Cherokees. I'm just not for sure on if a 27 spline gear will work on a 29 spline carrier. I would call Quinn at AllJ and find out the right gears for the KJ.

AWESOME, thanks Rock Lizard!! That was another part I was unclear on, until now, the spline count. Thanks for comin' through in the clutch for me!

unixxx · **Posted:** Sun Dec 03, 2006 9:44 pm

psinsyd, Rocky Road sells Yukon gears for about the same price. Although their website says they sell U.S. Gear for $195, if you phone them you'll find they're actually Yukon Gear for less than $195. Only the axle shafts are 29 spline on the 8.25"; the pinion is actually 27 spline: http://www.lostjeeps.com/forum/phpBB3/vie ... hp?t=13530. All 8.25" axles should accept the same parts. For this small change in gearing you can use the same carrier.

Check out these pages:

http://en.wikibooks.org/wiki/Jeep_Liberty/Gearing
http://en.wikibooks.org/wiki/Jeep_Liberty/Chrysler_8.25%22
http://en.wikibooks.org/wiki/Jeep_Liberty/Dana_30a

psinsyd · **Posted:** Sun Dec 03, 2006 10:07 pm

unixxx wrote:

psinsyd, Rocky Road sells Yukon gears for about the same price. Although their website says they sell U.S. Gear for $195, if you phone them you'll find they're actually Yukon Gear for less than $195. Only the axle shafts are 29 spline on the 8.25"; the pinion is actually 27 spline: http://www.lostjeeps.com/forum/phpBB3/vie ... hp?t=13530. All 8.25" axles should accept the same parts. For this small change in gearing you can use the same carrier.

Check out these pages:

http://en.wikibooks.org/wiki/Jeep_Liberty/Gearing
http://en.wikibooks.org/wiki/Jeep_Liberty/Chrysler_8.25%22
http://en.wikibooks.org/wiki/Jeep_Liberty/Dana_30a

Holy cow unixxx, now THAT'S research! Thanks a ton. I'll definitely check out the links. Thanks for the info.

chefdab · **Posted:** Mon Dec 04, 2006 2:18 pm

But if he only replaces the rear with 4.10 he won't be able to use four wheel drive until he can find a set of gears for the front.

Gris · **Posted:** Mon Dec 04, 2006 2:43 pm

chefdab wrote:

But if he only replaces the rear with 4.10 he won't be able to use four wheel drive until he can find a set of gears for the front.

Which is where the real problem lies.

I've been doing national part searches and can't find a single yard nation-wide that has a front diff from a 4-cyl.

I was really hoping to get the whole thing so I had a backup case and misc parts, but it's looks like I'm going to have to buy mine from a Mopar online seller instead. sucks.

N / A · **Posted:** Mon Dec 04, 2006 5:22 pm

how hard is it to change the gears?

unixxx · **Posted:** Mon Dec 04, 2006 6:52 pm

It's fairly technical and requires a few specialty tools. There's a great guide on it here: http://www.pirate4x4.com/articles/tech/ ... Gear_Setup

Tokyojoe · **Posted:** Mon Dec 04, 2006 8:48 pm

Who wrote those Wiki's? I thought the rear diff was 27 spline and 29 if you had the Trac Lock in it.

unixxx · **Posted:** Mon Dec 04, 2006 9:40 pm

I wrote them and just double checked the ARB catalog. The rear diff is definitely 29 spline.

psinsyd · **Posted:** Mon Dec 04, 2006 10:05 pm

chefdab wrote:

But if he only replaces the rear with 4.10 he won't be able to use four wheel drive until he can find a set of gears for the front.

Exactly. I was going to do the front and rear at the same time. I just found the gears on "the Bay" and was wondering if they were the right ones for the rear.

meduncan · **Posted:** Mon Dec 04, 2006 10:59 pm

Alright, I'll let you in on what is apparently a secret Jeep graveyard in the Midwest. The disclaimer is that I've gathered this information from my boss who owned a TJ and YJ and used these people. I don't know if they have Liberty's in house and I haven't purchased parts from them myself. However, if you're interested in parts then I'd start by calling Wabash Auto. They're located in Wabash, Indiana and their phone number is 260-563-7393. Maybe they've got a "spare" front end for you.

moose · **Posted:** Mon Dec 04, 2006 11:23 pm

So does that mean I could put the 3.73 in my 6spd when I go to 245's?

unixxx · **Posted:** Mon Dec 04, 2006 11:54 pm

Yeah, or better yet you could put 4.10 in your 6spd and go to 265's :twisted:

Although, I think the carrier break in the Dana 30 is 3.54 / 3.73, so you'd need a new carrier in the front. The rear is ok because it's carrier break is at 2.45 / 2.56.

OzLtd · **Posted:** Tue Dec 05, 2006 12:14 am

I've found a Jeep Wreckers here in OZ and am going to do a complete front diff swap with them, bolt in bolt out. Then just buy a ring and pinion set for the rear.

Does it matter if I have an ARB locker in the back ? Surely that new ARB carriers suits the 4.10 gears ?

Rear diff 4.10 gearing

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