Gearing help

[BSTJ]

Hey fellas,

Started regearing the old TJ in the driveway. 2003 X with dana 35. I'm dropping to 4.88 Yukon gears from the stock 3.73 and installing an ARB 30 spline with new hardened axles.

I've read quite a few of the posts and guides on this forum and YouTube videos from BFH and they have been a massive resource but I still find myself struggling to identify which way I need to go with my pattern.

The original pinion had a .045" shim so that was my starting spot. Backlash .008"

At this point, using Yukons instructions and pictures I thought I was too deep. This is the picture from the Yukon instructions I was using for guidance and the pattern I thought I most closely resembled.

I reshimmed the pinion to .035" with a backlash of .006" and got this pattern.

At this point Im struggling to understand the pattern. I understand that having a pattern run off the inner and outer edge of the teeth isnt a big deal. Using Yukon's pictures in their provided pdf I'm thinking I'm still too shallow? I see the harsh line on the bottom of the pattern but Im also willing to concede that I might have been too heavy with the compound. I also see on the drive side that the pattern looks like its running inside and off the top of the face of the tooth.

Anyways! This has been a fun project so far and I'm learning tons. Any input from the experts would be very much appreciated!

Thanks all!

 

[Rickyd]

Take another 10 out and see if it becomes shallow. It'll help you find the center

 

[Bigfoot-NM]

@hosejockey61

 

[BSTJ]

Take another 10 out and see if it becomes shallow. It'll help you find the center

Thanks for the reply. Cool so its your opinion I'm still too deep as well then?

 

[hosejockey61]

Thanks for the reply. Cool so its your opinion I'm still too deep as well then?

Yes you're way too deep. I'd take out 10 to start

 

[BSTJ]

Yes you're way too deep. I'd take out 10 to start

Thanks for the reply!
Work ran long so didn't get much time on it tonight. This is where its at now.

.025" pinion depth and .006" backlash

Still too deep I think. Maybe take another 5 out.

 

[hosejockey61]

25 thou doesn't sound like much. Do you also have a slinger under the pinion head?

Just making sure the carrier is on the right side of the break?

 

[BSTJ]

25 thou doesn't sound like much. Do you also have a slinger under the pinion head?

Just making sure the carrier is on the right side of the break?

There wasn't a slinger behind the stock pinion. Just a .045" shim then the bearing. I've also thought that 25 thou isnt much. But I'm thinking Im on the right track now just based on how I'm shimming backlash now. When I started with the original .045 starting depth I didn't have any shims in the left side of the carrier and like .060 on the right.

I bought the gears, carrier and axles as a kit. Think people around here call it the super35 kits.

 

[machoheadgames]

There wasn't a slinger behind the stock pinion. Just a .045" shim then the bearing. I've also thought that 25 thou isnt much. But I'm thinking Im on the right track now just based on how I'm shimming backlash now. When I started with the original .045 starting depth I didn't have any shims in the left side of the carrier and like .060 on the right.

I bought the gears, carrier and axles as a kit. Think people around here call it the super35 kits.
View attachment 623220

That doesn’t sound right. Do you have the bearings pressed all the way onto the carrier? In stock form, the Dana 35 only runs pinion shims from around 0.040-0.047”. I find it hard to believe that an aftermarket gear would want to be all the way down to 0.025” depth or less.

 

[BSTJ]

That doesn’t sound right. Do you have the bearings pressed all the way onto the carrier? In stock form, the Dana 35 only runs pinion shims from around 0.040-0.047”. I find it hard to believe that an aftermarket gear would want to be all the way down to 0.025” depth or less.

No reason I cant double check tomorrow. I installed them with a 20 ton harbor freight press until they stopped on the shoulder of the carrier. I'll throw it back on tomorrow and see if I was being too gentle.

 

[machoheadgames]

No reason I cant double check tomorrow. I installed them with a 20 ton harbor freight press until they stopped on the shoulder of the carrier. I'll throw it back on tomorrow and see if I was being too gentle.

Not necessarily being too gentle, but I’m just checking mainly that you used another race to drive them all the way on. Some people install them until the bottom out on the outside of the carrier, but the journal usually is thicker than the bearing and so the bearing ends up flush with the outside of the carrier, and not fully seated.

Having no shims on the left side sounds weird too (when the pinion was deep before). Maybe the ARB is just an odd duck. I’ve only geared a 35 with a truetrac before (with Revolution 4.56s), and the stock range of depth shims worked perfectly. what threw me off on the truetrac is that it was definitely machined with a right bias, and so I needed significantly less shim than stock on the left side, or else it jammed into the ring gear and locked the diff once the caps were tight. So I had to get special thin shims and hammer in a crappy shim stack each time I installed the carrier. Did not like that at all.

 

[BSTJ]

Not necessarily being too gentle, but I’m just checking mainly that you used another race to drive them all the way on. Some people install them until the bottom out on the outside of the carrier, but the journal usually is thicker than the bearing and so the bearing ends up flush with the outside of the carrier, and not fully seated.

Having no shims on the left side sounds weird too (when the pinion was deep before). Maybe the ARB is just an odd duck. I’ve only geared a 35 with a truetrac before (with Revolution 4.56s), and the stock range of depth shims worked perfectly. what threw me off on the truetrac is that it was definitely machined with a right bias, and so I needed significantly less shim than stock on the left side, or else it jammed into the ring gear and locked the diff once the caps were tight. So I had to get special thin shims and hammer in a crappy shim stack each time I installed the carrier. Did not like that at all.

I see what your saying. I did cut the cage off the old bearing and used it to press the new bearings into place. Like I said, no reason I can't double check when I have the carrier out again. Better safe than sorry.

I do have about .019 on the left side now that I have the pinion shimmed down to .025 now though.

I also agree with Hosejockey that .025 does seem really shallow. I'm not sure what to make of it. It didn't have a slinger nor did the rebuild kit supply a new one. Only thing I can think of is that this 4.88 pinion does extend pretty deep into the case.

 

[hosejockey61]

Are your gears standard or thick cut?

Anyway, let's see what the next pattern looks like.

 

[machoheadgames]

I see what your saying. I did cut the cage off the old bearing and used it to press the new bearings into place. Like I said, no reason I can't double check when I have the carrier out again. Better safe than sorry.

I do have about .019 on the left side now that I have the pinion shimmed down to .025 now though.

I also agree with Hosejockey that .025 does seem really shallow. I'm not sure what to make of it. It didn't have a slinger nor did the rebuild kit supply a new one. Only thing I can think of is that this 4.88 pinion does extend pretty deep into the case.

Rear axles, or at least D35s, don't have slingers, so you're good there. They just use the proper depth shim under the inner pinion bearing to shim the pinion head.

The shims for the carrier bearings sound super thin, but I'm not all that familiar with setting up an ARB. I know there is a master shim typically and so I am not sure what all comes together to make the total shim stack for an ARB.

I wonder if the weird depth is a Yukon problem. I haven't really heard great things about their gears for the last 5 years or so, whereas Revolution seem to be similar to stock in setup most of the time. I guess at this point continue on by removing depth and see where you land.

 

[BSTJ]

Rear axles, or at least D35s, don't have slingers, so you're good there. They just use the proper depth shim under the inner pinion bearing to shim the pinion head.

The shims for the carrier bearings sound super thin, but I'm not all that familiar with setting up an ARB. I know there is a master shim typically and so I am not sure what all comes together to make the total shim stack for an ARB.

I wonder if the weird depth is a Yukon problem. I haven't really heard great things about their gears for the last 5 years or so, whereas Revolution seem to be similar to stock in setup most of the time. I guess at this point continue on by removing depth and see where you land.

I intended to go with Revolution but then I found this entire package with the gears, arb and axles. I thought Yukon was reputable as you see them all over the internet but maybe I didn't do enough research. Luckily this isnt a daily rig so if things go south its just an investment issue for me.

Also to Hose, I dont see anything on the Yukon box indicating thick cut gears.

 

[machoheadgames]

I intended to go with Revolution but then I found this entire package with the gears, arb and axles. I thought Yukon was reputable as you see them all over the internet but maybe I didn't do enough research. Luckily this isnt a daily rig so if things go south its just an investment issue for me.

Also to Hose, I dont see anything on the Yukon box indicating thick cut gears.

Makes sense. I'm sure you'll get it in time.

There are no thick cut gears for Dana 35 (not worth it for the manufacturers since most people refuse to put money into the 35), so shouldn't be an issue there.

 

[hosejockey61]

Makes sense. I'm sure you'll get it in time.

There are no thick cut gears for Dana 35 (not worth it for the manufacturers since most people refuse to put money into the 35), so shouldn't be an issue there.

Yeah I didn't know if any manufacturers started catching up and making them. I didn't think so.

 

[Rickyd]

The way your pattern looks you can probably get pinion depth within the .025" that's left. Sounds like you have adjustment left for backlash too. That's all that matters

 

[BSTJ]

.0190 depth and backlash .005
How we looking

 

[BSTJ]

.0145 depth and .007 backlash here. I've definitely gone too far now. Going to start going back in now.