Attn Rawbrown and/or gear install guru's

I'm setting up the pinion bearing pre-load on my 92 reverse pinion D30.

My FSM calls for 20-40 in/lbs for a new bearings, and 10-20 in/lbs for the old bearings.

Are these initial settings correct?

I've pulled and added shims about 5 times here. Here's my results thus far.

Try ---- Inner Shim --- Outer Shim --- Preload Attained
1st ---- .010 ------------- .084 ------------- Loose (unreadable)
2nd ----.010 ------------- .096 ------------- Looser (wrong direction)
3rd ---- .010 ------------- .072 ------------- 2 in/lbs
4th ---- .010 ------------- .065 ------------- 8 in/lbs
5th ---- .010 ------------- .053 ------------- 36 in/lbs



36 "feels" pretty damned tight. If the 20-40 in/lbs is correct, then I'm going to back it off a bit and run .056 shims and bring that number down a bit.

Can someone please confirm my findings?



Thanks in advance.

I typically run 20~25 without the seal on new bearings.. I would throw another .003" in there and see what it is..

another thing I'm noticing is the threads on the pinion nut and pinion are starting to get gauled.

I'm afraid that if I keep pulling it off that the threads will be unusable.

I'll add another .003 and I should be good there.

Then we'll see how many times I gotta pull it out to set the pinion depth

I use an old D44 ball joint castle nut for setting up the pinion untill its all ready then the stake nut with locktite.. but yeah look carefully at it before putting it on for the last time..

I don't fawk with pinion preload till I've figured out the depth. you can set the pinion preload temporarily during gear install by simply using no shims and tightening the pinion nut till the proper preload is obtained. just go slow and don't overtighten the pinion nut. if you do, then back the nut off a few and loosen the bearings with a soft metal hammer. Then retighten. you don't need to gun down the pinion nut balls tight just to get a pattern. you just have to make sure that the bearings are all correctly seated.
Here is what I do.
on my evertime I think I have the pinion preload set right I grab my copper hammer. I hit the backside of the pinion yoke as iff I'm trying to remove it but the nut is in the way. this helps ensure that the critical inner pinion bearing cup (outer race) is fully seated. then I hit the yoke back to ensure the outer bearing is seated. then I tap the threads to push the bearings apart. If things tightened up by the hammer then your temp preload should have loosened up a schosch. tighten it up with a quick blip of the impact gun on a low/med setting and hammer the yoke again. This will guarantee the most acurate pinion depth setting. I run around 18-22 on new bearings without the seal as per the instructions given to me by the gear vendor that I'm installing. I think yukon recomends 15-18 or something like that.
Not until I have established the correct pinion depth and backlash settings to I do what I call final assy. at this point I remove the pinion and calculate my shim pack. usually something in the .060-.070 range is what I typically see. I make small changes one at a time to correct the preload. .003-.005 shims are all that I add or remove. when that is set I remove the yoke and install the outer slinger and oil seal. install the yoke and a new washer and locknut. (during pre assembly I used the old pinion nut that I removed during teardown) then I pop the carrier in and verrify the pattern. for some strange reason It always gets a little better after final assy.

FWIW, grind off the locking portion of the old pinion nut and use it during your set-up process. This will eliminate the potential damage to the pinion threads.

Dana spicer uses prevailing torque locknuts. Its a regular grade 8 nut that is deformed on one side. to grind would mean drilling out about 3 threads. The threads on the pinion shaft are hardened 8086 steel or something like that. If a pinion nut ruins the threads on the shaft then thats a crappy gearset. I've sent gears back to the mfg for not being properly hardened. When a copper hammer can deform threads on a pinion shaft... it doesn't belong in an axle.
if the threads get ugly. try cleaning them out with a wire brush. you can go down to your local NAPA and grab a new pinion nut for a buck or two.

Frank Z said:

FWIW, grind off the locking portion of the old pinion nut and use it during your set-up process. This will eliminate the potential damage to the pinion threads.

Click to expand...

Thanks for the feedback and advice.

I'm going to go pickup a new standard nut for doing the setup. The old pinion nut is falling apart on the inside. Hardened or not, forcing those shavings into the tight area of the threads can still cause damage to the pinion threads. So I'm not going to chance it with this old nut.

always make sure the threads are clean. don't know how many times I've pulled the nut off and wondered about the threads only to clean it with a rag and maybe a wire brush to find the threads perfectly fine while the nut itself has gone to hell.

haha I hear ya there.

I'll definitely use a wire brush on it after I pull it again. I'm going to add .003 to it and then start on the backlash.

Thanks again for the advice.

I've pulled the pinion out 6 times now, in an effort to get the pinion bearing preload set correctly.

On the 4th time pulling it out, I noticed that the threads on the pinion nut and pinion started to gaul. So I quickly changed to a new nut and wire brushed the pinion threads. They showed very minor wear and damage so I figured a bad nut might have caused it. Nope. With a brand new nut the threads continued to shred and gaul.

After taking out the pinion for the 6th time, the threads are now unusable.

How can this be? I have not crossed any threads, I have not dropped the pinion, nor have I beaten it or mistakenly hit it with a hammer. I have been using a rubber mallet all around the differential to prevent any damage.

From 4 Wheel Parts Website....

4wheelparts said:

When you are looking for a high quality performance gear set with an economical price you have both in Genuine Gear. Made from high quality 8620 heat treated forged steel for durability and shot peened for quiet operation.

Click to expand...

It's as if they didn't heat treat the metal to harden it at all. Needless to say, I am going to return the 2 gear sets and the 1 remaining master install kit. I don't think I'll be able to return the 2nd master install kit as it's 1/2 used on this attempt.

I will be looking into Yukon gears or some other quality brand.

Pics here...











I hope they don't give me any crap when trying to return these. I do NOT want to chance it with a 2nd set. I flat out do not trust Genuine Gears. I've read all the horror stories, but I figured I'd give it a try. I guess I should have listened to what I was reading.

Genuine Junk, there's your answer! When I used to do Jeep gear installs I told people flat out, don't bring 'em because I won't put 'em in.

How about a brand new Spicer yoke that wouldn't even start on the splines of a brand new Genuine pinion? Or a ring gear that wouldn't bolt to a carrier because the holes didn't all line up? Or a different ring with 9 of 10 holes tapped?

Junk.

you can save those threads if you want. since its at the outer end. you need to chasethe threads with a file then use a plain nut for setup. add a little oil to the threads.

I did that already. That's when they got worse.

I could feel resistance as I tightened the nut (standard nut) and the yoke pushed the outer bearing onto the pinion, more than I should have felt. I'm talking I felt the threads not acting like they should have been. On the way out, I felt the threads binding up, and that was the pieces that broke off being jammed up in the works.

At this point I either want to exchange for some Precision Gear's, or get a refund. The 15% restocking fee is going to suck though.

I guess I could always try another set of GG's, to avoid any fee's whatsoever. Perhaps I might get lucky with another set. Who knows?!?

Got any used sets of 4.88's Rawbrown?

If not, how much can you source some new ones for?

Ok, 4 Wheel Parts was cool with me wanting to exchange for a new set of gears. They saw the damaged threads and exchanged them under warranty.

Now to see if I can screw up a 2nd set of threads.

I'll use some anti-sieze on the threads this time. I was told it will help.