Differential Master Overhaul Kits

tommudd · **Posted:** Wed Nov 19, 2014 5:12 pm

Wouldn't do Motive, mine are getting louder and louder . All gears are not created the same. I'm having my rear gears redone after 80,000 miles due to the whining. They used to be pretty good but apparently not any more , local shop said they have quit using them altogether

NAMoulton1 · **Joined:** Tue Aug 12, 2014 7:01 pm **Posts:** 1054

I've spent more than a few hours searching for a 29 spline ring and pinion to no luck. I'm thinking that the distribution websites just don't have the right information. Because there ARE people with 4.56s...

lfhoward · **Posted:** Wed Nov 19, 2014 8:11 pm

NAMoulton1 wrote:

I've spent more than a few hours searching for a 29 spline ring and pinion to no luck. I'm thinking that the distribution websites just don't have the right information. Because there ARE people with 4.56s...

Jeepin_it_real had 4.56's. His sig said his were Superior gears.

Bmxer524 · **Posted:** Wed Nov 19, 2014 10:00 pm

Motive and G2:
http://www.4wheelparts.com/Drivetrain-D ... +29+Spline

I've also been told that spline doesn't matter. I can use the ring and pinion from a 27 spline 8.25. Is that true?

NAMoulton1 · **Joined:** Tue Aug 12, 2014 7:01 pm **Posts:** 1054

Bmxer524 wrote:

Motive and G2:
http://www.4wheelparts.com/Drivetrain-D ... +29+Spline

I've also been told that spline doesn't matter. I can use the ring and pinion from a 27 spline 8.25. Is that true?

The header does say 29-spline. But when I've cross-referenced the gears on other websites their specs say they're a 27-spline.

I would think fitting a 27-spline into a 29-spline would be like a triangle going into a square...with a very big hammer. I could be wrong about that though...I'm still new to the automotive world haha.

NAMoulton1 · **Joined:** Tue Aug 12, 2014 7:01 pm **Posts:** 1054

lfhoward wrote:

NAMoulton1 wrote:

I've spent more than a few hours searching for a 29 spline ring and pinion to no luck. I'm thinking that the distribution websites just don't have the right information. Because there ARE people with 4.56s...

Jeepin_it_real had 4.56's. His sig said his were Superior gears.

That it did...unfortunately, I cannot the brand Superior anywhere haha. I think they were swallowed up by this new "Revolution" brand. http://www.revolutiongear.com/

They may have the 4.56s too:
https://www.4lowparts.com/product/revolution-ring-pinion-chrysler-8-25/
https://www.4lowparts.com/product/revolution-ring-pinion-dana-30-front-jeep-jk/

Bmxer524 · **Posted:** Thu Nov 20, 2014 7:14 am

From what I'm reading, it seems as if you can buy any ring and pinion for a Chrysler 8.25 and it will work. The only parts that won't interchange between 27 spine and 29 spline axles are carrier bearings, the carrier, side gears and axles. I think it might just be easier to call a pro and find out for sure though lol

NAMoulton1 · **Joined:** Tue Aug 12, 2014 7:01 pm **Posts:** 1054

Bah-humbug...professionals cost more money than they're worth haha. I do think I'm going to call the manufacturers to get more information on some of these though...

Bmxer524 · **Posted:** Thu Nov 20, 2014 2:14 pm

This should help:
http://www.naxja.org/forum/showthread.php?t=1096143

Professionals are normally free when you call up inquiring and just asking questions. My friend said whenever I'm ready let him know and he'll do my gears. He said it's easy, the hardest part is the front just because you have to drop the diff. He also said his gear guy has been doing them for decades and loves that kind of work lol.

NAMoulton1 · **Joined:** Tue Aug 12, 2014 7:01 pm **Posts:** 1054

Ain't there splines on the back of the pinion gear? Which connects to a thingy which does stuff which eventually is spun by the driveshaft, right? Sometimes I really wish to go to school for this stuff haha, I know nothing...

I'm looking for someone to teach me how to do my own gears...I'm too much of a DIYer haha.

Bmxer524 · **Posted:** Thu Nov 20, 2014 6:16 pm

One of these days I'd like to learn how to do gears. I fear I might not have the patience though. I heard it's really intricate.

NAMoulton1 · **Joined:** Tue Aug 12, 2014 7:01 pm **Posts:** 1054

That's my kind of style...until its sledgehammer time....then THAT'S my style haha. One part of my job is building connectors, whether it be Cat6 (ethernet cable), electrical outlets (120/240V), or the really intricate stuff...fiber connectors (biggest pain in the @$$ ever) haha.

JeepMonkey190 · **Posted:** Fri Nov 21, 2014 5:45 pm

I'm looking at doing some 4.56 too I believe the front is a "short if I'm not mistaken but it is a bummer that pro's cost a good amount but you have to remember if you do the install and it ends up destroying your jeep your paying for it out of your pocket but if a pro does it and that happens then they pay for the mistake and whatever needs to be fixed.

IMO I would rather pay the $1000 to have them installed than risk having to pay for a new jeep :2cents:

Im a huge DIY guy since I have done everything to mine myself I just draw the line at gears :5SHOTS:

Ted15 · **Posted:** Fri Nov 21, 2014 5:53 pm

the pinion is the most important part, if it's not properly installed it doesn't matter about the backlash. It moves and wipes out the ring while destroying itself. Shop around and don't look at the price as much as the shop's ability and reputation.

Bmxer524 · **Posted:** Sat Nov 22, 2014 12:57 am

Ted15 wrote:

the pinion is the most important part, if it's not properly installed it doesn't matter about the backlash. It moves and wipes out the ring while destroying itself. Shop around and don't look at the price as much as the shop's ability and reputation.

I'm curious. What kind of rpms are you turning at 70mph? I've spoken to a few people and they're saying that 4.10s with 32s will put me right back at stock. I'm not sure anymore. The power would be nice, but I see a ton of highway. So turning 2700rpms at 75 isn't ideal. Especially since I'm at sea level with no hills.

Ted15 · **Posted:** Sat Nov 22, 2014 1:02 am

I'm not sure but somewhere around 2000-2500 (?)
4.56 would correct for 32's 4.10 is for 31's (also 245/75-16)

tommudd · **Posted:** Sat Nov 22, 2014 1:52 am

Bmxer524 wrote:

Ted15 wrote:

the pinion is the most important part, if it's not properly installed it doesn't matter about the backlash. It moves and wipes out the ring while destroying itself. Shop around and don't look at the price as much as the shop's ability and reputation.

I'm curious. What kind of rpms are you turning at 70mph? I've spoken to a few people and they're saying that 4.10s with 32s will put me right back at stock. I'm not sure anymore. The power would be nice, but I see a ton of highway. So turning 2700rpms at 75 isn't ideal. Especially since I'm at sea level with no hills.

You'll still be a bit lower on the RPMs with 32s and 4.10s
Like Ted suggested 4.56s for a number of reasons, the extra height of the tires, the extra weight of wheels / larger tires and other add-ons , plus little extra RPM won't hurt a thing
For example mine still runs a little lower on RPMs than one stock from what I have been able to remember and talking to others. If I dropped to 245-75-16 or 265-70-16s ( almost same height) I think RPM and power would be ideal

Ted15 · **Posted:** Sat Nov 22, 2014 8:28 am

When my computer is reset, before it has a chance to "correct itself", I have plenty of power. Actually, it runs great. I wish it didn't change. It still runs pretty good though.

Ted15 · **Posted:** Sat Nov 22, 2014 8:35 am

I was just thinking about how it ran before I changed anything. With 3,73 gears and 29" tires, it had a little pep but was doggish so a few more rpm's would probably be a good thing. Don't expect great mileage either way. The best I ever got was 16 mpg and that wasn't for very long.

NAMoulton1 · **Joined:** Tue Aug 12, 2014 7:01 pm **Posts:** 1054

So...was it ever answered that a 27 spline ring and pinion fits with our 29 spline? I may buy my rear ring and pinion/install kits this paycheck...

Differential Master Overhaul Kits

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