Question for the guys that know how to set gears up. I’m trying to set the pattern on my gears and I would like ya’ll to take a look at it to see if I’m close enough or if I need to make any changes.

The axle is a Chrysler 9.25 and I’m pretty sure the pattern looks good, but then again the pinion might be too deep. If ya’ll could look at the pinion and give me your opinion, I’d appreciate it. If you need more info, just let me know.

I’d have to get my numbers out but the stock shim put the pattern really close to the top, pretty much centered… I added the largest shim that came with the install kit and it put me at where I am now. If the pinion is too deep then I was going to half the distance from what I have now…

Thanks for the help


Drive:






Coast:

 

Actually, your pattern looks pretty nice. Pinion might be just a shade deep...... Up to you if you wanna toss another shim in there.

 

Do you think a pattern like that would cause any noise in the rear end from the gears?

The long story behind it all...

It's a work truck that we have. One of our guys was driving around out of town in it and heard the rear end starting to make a really loud roaring noise. He took it by the quicky oil lube and it turns out it didn't have any lube in it... or very little. They filled it up and the noise continued.

Me and some guys started brainstorming and taking things apart. We were thinking either the axle bearings are bad or the carrier/pinion bearings are bad. Turns out the clutch pack retaining clips (LSD) tore apart and got lodged into the oil passages for the pinion and various other places. The gears also looked like they might have been pretty chewed up as well. With the lack of oil that was found we decided to replace the ring/pinion, clutch packs, and all associated bearings. Me and another worker got everything changed and buttoned up with the gear pattern you see above which I thought would be sufficient.

Unfortunatly, that was on Nov 21 and we didn't test the truck out that night as it was really late and the battery was dead. I went in for surgury the next morning... and again a week later. Some other guys test drove the truck and said the noise was still there, just not as loud. They stopped driving the truck until we can get things situated. We broke the rear end down again and ran a pattern, which are the above pictures.

I just wanted to let others look at the pattern to see if things need to be changed. I think it looks pretty good but if something needed to be changed I would think the pinion depth would need to be decreased. The inital pattern showed the pinion depth to be to shallow so we added the thickest shim in the kit which gave us the above pattern. My thoughts, if the pinion is adjusted again, are to decrease the shim stack by half of what it is now. That should bring the pattern closer to the top of the tooth without going to far as with the orginal shim. The original shim was just too shallow, but not by much at all so half of the second shim stack should put it in the sweet spot if it's not there already.

If the pattern we have now should create a roaring noise in the rear end then the only thing I can think of that would be making that noise would be the axle bearings (u-joints for the drive shaft seem good)...

We tried to replace the axle bearings when everything was dismantled in the first place but the puller we rented wasn't getting the job done so we just kept the bearings in.

Any ideas or thoughts would be appriciated.

 

I can't tell myself, but I'll toss this link at you just in case, as I'm presuming you already had the spec numbers to get where you are now.

http://dodgeram.org/tech/specs/axle/rear_axle.html

 

Yeah, that's the sheet I am using to get the backlash and various preloads, thanks!

 

+1 with HeyYou's post. Are you sure the sound is coming from the rear end? Is this a 4x4 or 2wd. If you could add some info about your truck that would be great, like year/model/auto/stick etc.

 

It’s a 2004 Dodge Ram 1500 2WD Automatic. It had 3.92s in the rear end that I replaced with a 3.90 Motive Gear set and install kit. I got the clutch pack from Randy’s R/P. If any other info is needed I'd be happy to provide it.

It sounded like a bad bearing to me. You'd get above a certain road speed and start hearing the roaring sound. The faster you went the louder it would get. It was speed dependent vs. RPM dependent. We jacked the back end of the truck up and put it through it's paces (safely) while it was stationary and tried to determine the location of the noise but couldn't quite pinpoint it other than from the axle. That's when we opened the pumpkin up and discovered chunks of metal... upon futher inspection we identified them as the clutch pack retaining clips... then found them in the oil passages. I thought the bearings just got starved of lubrication and started to fail...

 

Did you inspect the axle bearings? If you are low on fluid, they will fail first.

 

I did inspect the axle bearings when it was taken apart. From the outside they looked ok and everything seemed in order. With the axles installed there is no axle up/down/left/right axle movement... but I did not realize that the bearings would fail first... makes a lot of sense though.

Our intention was to replace the axle bearings and seals when we were putting everything back together. Unfortunatly we rented the wrong puller for the bearings. We were given the 2 and 3 arm puller w/ slide hammer but we found that won't work on our particular bearings.

We have the bearings and do plan to install them... we just have to get the old ones out.

 

Did you replace the side and spider gears? and did you re-use the org carrier? When the clutch packs go south the side gears have a tendency to gouge out the carrier and that will make some sound.