Re: Very Bad Vibration
 

The marking compound is called "Prussian Blue" and I bought it at Napa.

The cursory check of a poorly shimmed rear diff is grabbing the flange (like you said) and seeing how much rotation you get before your axles start to turn. The factory service manual has a spec on it, I believe it is like 5mm.

It isn't really smart to use a bearing with a different race, as they wear together, but I doubt that alone was the problem, again, talking about 5mph.

I've rebuilt a DSM rear diff (the correct way) and I actually have the special tools for it and know how to use them, unlike 99.7% of dsm folks. You can PM me with questions if you want.

Re: Very Bad Vibration
 

That spacer is a shim. It is a good idea to swap it over to the new pinion so you can get a start on your gear pattern. Then after you see what pattern you have, you can adjust the shim to get a good pattern. If you didn't swap anything over, I can guarantee you that your pattern is off. I'm willing to bet the backlash is way off.

Re: Very Bad Vibration
 

So should I or should I not swap that bearing/shim? I will check the rotational measurement in the morning. Thanks for the help so far guys!

Re: Very Bad Vibration
 

If it was me, I would check the pattern first. If you didn't put that shim on the new pinion, your pinion to gear ring contact must be way off unless the new one came with a shim as well. Did you use a new crush sleeve when you reassembled it?

Re: Very Bad Vibration
 

checking the play in the rear end is way easier, and I believe that is the first step the FSM recommends.

Re: Very Bad Vibration
 

If you changed ring and pinion gears, you have to check contact pattern.

Re: Very Bad Vibration
 

I believe it came with a shim but I'm not 100% sure because I didn't swap any of that over. I will take the diff out tomorrow. I did not use a new crush sleeve but am now seeing they are non-reusable.

Re: Very Bad Vibration
 

I'm willing to bet the vibration at 5mph is from the rear diff. It wasn't setup correctly. Get the right pattern and fix that rear camber asap. The driveshaft would give you a vibration at higher speed unless the hanger bearing rubber ripped right off but the low vibration is probably coming from the rear diff.

Re: Very Bad Vibration
 

DSM Diffs do not have crush sleeves.

Re: Very Bad Vibration
 

Good to know. I've read a couple threads on getting the correct pattern. Some mention to measure backlash before painting the teeth and doing the pattern test. Any thoughts on that?
I'm going to remove the diff today and take a look.

Re: Very Bad Vibration
 

If you're removing the diff then measure backlash and gear contact pattern.

Should be plenty of internet resources that can tell you how.

Re: Very Bad Vibration
 

Heres before it comes out. I think you guy's are right with it being something to do with the rear diff. I don't have a tool to measure backlash. Anyone on here have something?
I'm guessing this is way out of spec and should be less.
https://www.youtube.com/watch?v=PNoNwndyN9c

Re: Very Bad Vibration
 

that's quite a bit, certainly out of spec. Although 5mph vibration worthy? We'll see I guess!

Re: Very Bad Vibration
 

Still need to get the gear marking compound but here's just a quick look inside.

Re: Very Bad Vibration
 

Lol, looks to me like there is no preload. Definitely not good. That pinion and differential needs to be shimmed and have the preload set correctly.

Re: Very Bad Vibration
 

Feels like there could be none when driving lol
The vibration does get a lot worse with increased speed.
Might double check my work and that there is actually a shim on the 5 speed pinion gear/shaft I got.

Re: Very Bad Vibration
 

Well this is what I got so far. Confused as to which is the shim. I'm guessing it's the one my finger is pointed at because the one i'm pointing out with the screwdriver looks to be the same on both shafts and non removable.
If it is the one i'm pointing at with my finger than that is being used from my old gear set along with the sleeve which could explain why the new gears would be off.
Proven Force be able to help me with this? I don't have any dials or anything to measure with. I'm guessing it needs a thicker shim to move the gears more towards the center?


Just noticed the one my finger is pointed is a thick and thin "shim" if that's what those are. Here's a pic of what I mean

Re: Very Bad Vibration
 

there are 2 shims, outer and inner. To move the pinion in/out, you have to change both accordingly, as the distance between the nut and the gear is fixed and you need to fill it with shims, bearings, etc.

I'm sure proven force can help you. No idea how much they charge.

A dial indicator is maybe $20 at HF and is accurate enough for your purposes.

The problem is if you need to change shims, you'll have to order the full set for each shim, and I think it was maybe around a $80-$100 investment for all of them. I might have spares i'd sell individually if you determine what size you need.

Do you have a factory service manual? I highly encourage it for all DSMers.

Re: Very Bad Vibration
 

Ok I will look into that HF dial. I do not have a service manual, just the good ole Chiltons. Where did you order these shims from? TMZ, Jacks, Proven Force, Ebay? lol

Re: Very Bad Vibration
 

Proven Force is helping you right now. Lol, I work for Proven Force. But im sure Chuck at Proven Force can help you find those shims. Otherwise I'm sure we can build it for you.