Weird rear wheel movement

I've been "daily driving" my Buick for the last week or so. All has been great, except for a weird clunk.

So today I jacked up the car to see what was going on. I thought I might have a loose tranny mount or something.

Turns out to be some sort of problem with the rear end. When I grab the rear wheel, I can move it in/out about 1/16" (guess). Actually this happened with both rear wheels.

The rearend is a bit unusual- it was built with some Moser axles, and instead of using the c-clips or c-clip eliminators it has some other type of axle. (I don't know exactly what it is, but people who know their rearends seem to know what this means. I think it's something like how a Ford 9" works, but I don't know.) It was rebuilt about 3 years ago with a new gearset and new posi unit (thanks, Monzaz!). In case it matters, it is a 12-bolt w/ 2.56 ratio.

Anyhow, I assume that when I grab the wheels, they shouldn't move in-and-out. There is no up/down play, or front-to-back play. Only in/out (i.e. toward/away the pumpkin).

So what is wrong? What do I do about it? Can I fix this myself?

I've parked the car and resumed using my winter vehicle. I hope this isn't a death blow...

Thanks!

-Bob Cunningham

 

So was this a rear I built? If so please talk to me about the rear I will help you out.


Only very small amount of movement .001 -.015 on a bolt in axle, c-clip will be a bit more axle end play if the axles are used as the c-clip button wears over time.

If I did build this I do not normally put ford ends on 12 bolt stock rears I use Moser c-clip eliminator kits and that would be for a race rear not street.


Please if you can make it clear whether you are thanking me sarcastically o No: (not GOOD) or for real... for parts I sold you that do work... hopefully this is the case.???...???o No:

As I stated either way I am here to help you out. Jim

Please post pictures of the area of concern so we can see what bearing system you are working with. Hope to help get your car back in shape.

Jim Mitschke

 

Sorry! I was 100% sincere in thanking you. Actually the work was done by a local guy in Florida, but you supplied the parts (posi unit, gears, etc.). And you were VERY helpful, just as everyone always says on this board. You probably don't remember, but we shipped the old parts up to you and you gave us a very good assessment of the old parts. You also set up the new posi unit especially for my application, and it's been great ever since.

I was actually thinking that I might have to load up the van and drive out to Ohio to have you look at this, in the case that it turns out not to be something I can handle myself. I can swap a whole rearend, and I can work on brakes, but I'm not all that familiar with the innards of a rearend.

Originally, this rearend was built by a guy named Art Houser in Pennsylvania, sometime in the mid '90s. He used some special Moser axles, and whatever it was about these axles apparently didn't use a c-clip, and it didn't use a c-clip eliminator. I wish I knew more, but I'm just out of my realm. Not that I'm dumb, I just have never learned much about rearends (except that tall gears are good, and posi is good).

Sorry that I don't have pictures, I just discovered this tonight and when I discovered the problem I just put my stuff in the other car and went home. I didn't want to open up the cover because I didn't have the time or supplies (new fluid, posi additive, gasket, etc.) to work on it. In fact I don't know if/when I could do that, because I don't have a spot to make the car immobile while I pull it out. I don't have my own garage, and I have to make plans in advance when I will tie up my brother's garage for a while.

I don't know if any of that helps you figure out what is going on in this rearend, but maybe I can answer more questions...

-Bob C.

 

Well to tell you it just sounds like you roached the axle bearings. If he used Hobby stock axles from Moser they are on a BALL bearing type axle bearing and could have possible worn out already.... OR the housing ends are not quiet true making the bearings wear prematurely?

I do sell Moser products and can help you get the parts if we find out more info. so do not worry too much as anything can and will be fixed. Jim

 

OH ...The ME totally through me off from Florida... I do totally remember this Posi and gear set purchase well. That was kind of cool we did the 33 spline 2 series 12 bolt rear. I am positive you have the GM drum boly flange with the large Ford bearing installed might be the RW508cr bearing with outer imbeaded rubber seal around the outer diameter of the bearing. Then is retained with a 3/16" retainer plate that slides down on the axle and bolts to the axle flange holding the backing plate and axle in the housing.

SO I would say you just plain kill the bearings and they are very readily available. The only issue you will have is to find a shop with a at least 12 ton press (should not be too hard) to press the old bearings off and the new on. Jim

 

If that is all it is, there is a shop near me that can do a lot of axle/rearend work. I've used them for other rearend work in the past with great results, but they have never been in this particular rearend.

So my next question, if you don't mind, is how to do this economically. Like I said I'm pretty mechanically apt but I've just never been inside a rearend. So should I just pull the whole rearend and bring it to a shop? Or, is there some other work I can do (i.e. remove axles or something, which I've never done but I could probably figure out with the right guidance) to minimize the labor at the shop? Maybe I should do a certain amount of disassembly, so that I can confirm which bearings are in there, before I bring it to the shop?

And, since I've been running the rearend for about 3-4 years now, is there anything else I should check out while the rear is apart?

Something else doesn't make sense to me. Like I said, I've never really done anything inside a rearend, so I'm a bit confused. I thought that the axle bearings were what I would call "radial bearings" - i.e. their job is just to hold the axles concentric inside the axle tubes. But this problem seems almost like what I would call a "thrust bearing" issue (i.e. a bearing which would prevent the in/out movement). Sorry if my terminology is all messed up, I hope you understand my confusions...

Maybe some sort of a diagram would help me understand what bearings are in there. I'll try google...

(In fact, I do work at a company with a very large machine shop, and I'm sure they would have a 12-ton press - is this something I want to try totally by myself?)

Thanks a million!

-Bob Cunningham

 

BOB, who did the last work on the rear? Who installed the ring and pinion and gears? That repair person had to go into the rear and remove the axles to do this work.

NOW this is hypothetical... They could of had trouble removing the axles when this work was done and could of had some unsightly damage to the bearings upon removal ...sometimes with out a puller that keeps pressure on the bearing in out upon remove ...like a hammer hitting the back of the axle flange at angles will take life from the bearings (axle bearings that is)

I am not saying by any means the guy messed up the rear axles...but you can find out the way he/she removed them to service the rear when you had the work done. It will give you some ideas as to the way they work as a shop etc.

Anyway it could have just been the time for the bearing to go as you do drag race the rear pretty hard correct? How old were the bearing before that?

You can pull these axles out WITH OUT removing fluid and or disassembling the whole rear. just pull both axle by removing the retaining plate bolts (same ones that hold the backing plate on) and pull straight out ... the reverse drum as a slide hammer does work quit well....BUT try to use a older junk drum if you really have to do some hard banging.

If you run into trouble just ask for help and or call me . Jim

 

Long story here... I was going back to school full time, and working full time from 2003 to 2005. During that time, since I couldn't work on the car or anything, I gave the car to my father in Florida to drive for the few years (instead of just letting the car sit). My father works for a local RV repair center, so when he had rearend problems with my car he brought it to an affiliated shop who does some of the "heavyier duty" work on the RVs (and they also work on cars). It is a large, well-equipped shop, and I'm sure that they would have a much larger press than just about any standard automotive shop. Very knowledgable, and a very well reputed shop in that area of Florida.

Anyhow, I have no idea what other work he did in the rearend. For all I know, he didn't look at the axle bearings at all- if his purpose was just to replace the bad posi unit then he might not have looked at anything else. So the bearings might be 15 years old.

Some questions for you:
1) So are the axles just a press-fit into the differential?
2) I assume the rear should come out of the car before I try to pull the axles?
3) Once I remove the axles, then do I just bring the rearend (less axles) over to my shop to replace the bearings? Or will the bearings come out with the axles?
4) If the last guy might have damaged the bearings by pounding them, is it really such a good idea for me to try removing the axles by pounding them some more?
5) I have been told that my input pinion is too small, for the amount of torque I'm making. If I remember my numbers, the u-joint is a 10-series (3110?) and I should really have a 50-series (3150?) back there. Do you agree that I should change that out, and if that's the case should I just bring the entire rearend to my local shop to do? Are parts for that hard to get?

If these are easier to discuss over the phone, just let me know and I'll give you a call. I know that sometimes these notes take a while to type, and maybe it would just be more efficient to discuss...

Thanks,

-Bob Cunningham

p.s. Although I'm always looking to do thing economically, if I have a better chance to get things "right" by spending some money then I'd rather not risk anything. At the moment, I have enough money to do things "right" (but not wastefully)...

 

Bob, well if the rear is 15 years old I would say you got your life out of the bearings and then some...lol.

YOU DO NOT need to remove the rear end to do the axles at all.

If the axles have a access whole though the flange then you will remove the 4 bolts and pull the axles out...The bearings will come out with the axles they are pressed on to the axle shafts. Then you take the axles to the shop with the press and they will replace the bearings and then you take them back home again and slide them in and put the four flange plate bolts back in at about 35-40 foot lbs and away you go again. Jim

 

Well that sounds like something I can do then.

Thanks for the help Jim! I'll let you know about any problems/questions/success.

-Bob C.

 

I can't figure out how to take this apart - here is a photo of the axle with the backing plate disconnected... How do I take this axle out?

Thanks!

-Bob Cunningham

 

Bob
If you have a slide hammer attach it to the axlex studs and give it a couple of good wack. If you don't have that get a chain and go around your axle leave some slack in it and snap it like a whip. A heavier chain makes it easier.
Hope this helps.
Rick

 

Bob they must be stuck. Pry on one of them, i'll bet they will come out.

 

I don't see any type of axle retaining flange in that photo. Did the bolts just go through the backing plate and into the axle housing?

 

There is a square flange behind the backing plate. The bolts went though the plate and into that square flange.

-Bob C.

 

Guys!

That looks to me like a Chevy C clip axil bearing.

Bob, take the back cover off and look at the ends of the axils and see if there is a c clip holding them in. If there is that is your "chucking" back and forth.

Mike

 

Mike-

The rearend was made with some Moser axles that are specially designed to use a different arrangement - no c-clips, no c-clip eliminators. Supposedly something like a Ford setup...However I don't actually know what's holding the axles in, and I'm nearly to the point where I'm just going to remove the whole rearend and bring it to someone that knows more about those setups.

Going by what people are saying above, a slide hammer should pull the axles out. But if that actually were to happen, I would think that the axles would have come out during some hard cornering. So I'm nervous about just getting a slide hammer and whacking the crap out of it in case there is some other way that the axle's supposed to come out.

Thanks for the help!

-Bob C.

 

I don't know Bob

I would pull the rear cover off and look in there and see what it has. Looking at the picture you posted there isnt anything out there holding in the axil. If it had a pressed on bearing the 4 bolts you took off would have contained a plate that held the outside of the bearing into the housing. What I see there is the standard Chevy style stub hanging out that has a "needle" bearing style bearing in it.

Pull the cover and take a picture and we will see if we can help you out!

Mike