• When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.

Rear axle alignment issue, whats causing this problem.

67 coronet said:
if the end were replaced at one time,my guess would be the culprit is there.a bent wheel would hit on one side and then the other if spun 180 degrees.only the axle or the mounting can cause it to hit in one spot.if you measure from the leading edge of the axle flange to the front spring perch do you get the same or diff #'s?
Click to expand...

I checked that, and on the driver side the distance is 1/4 inch more then the passenger side. As far as front to back on the passenger side, it appears to be off by about 1/16 inch, however, with that said, I suspect that I also have a bent axle shaft flange, and that may be why when rotating the wheel on that side half the tire rubs and half doesn't on the front of the leaf spring. Again, ether way, there is something off on that passenger side, whether its the new end was not put on correctly or the perch was never to spec, I still have to check that axle shaft.

- - - Updated - - -

Oh, if anyone happens to have a 8 3/4 from a 73 RR/Satellite, I would like to get some measurements. I don't think the service manuals have that data. I just want to verify the axle flange to spring perch distance as well as perch to perch and over all distance from flange to flange.
 
Correct me if I'm wrong but isn't an 8 3/4 axle housing tube about a 1/4 inch longer on the passenger side? Two different lenth axles?

It seems that you definitely have something bent or miss aligned but if I'm correct about the tube lengths you wouldn't want the same measurement on each side.

(I swapped out an 8 3/4 for a '70 E body Dana and gained a 1/4 inch clearance on the passenger side...)
 
khryslerkid said:
Correct me if I'm wrong but isn't an 8 3/4 axle housing tube about a 1/4 inch longer on the passenger side? Two different lenth axles?

It seems that you definitely have something bent or miss aligned but if I'm correct about the tube lengths you wouldn't want the same measurement on each side.

(I swapped out an 8 3/4 for a '70 E body Dana and gained a 1/4 inch clearance on the passenger side...)
Click to expand...
Nope, they are equal length....and it wouldn't matter if they were longer because the distance from the bearing shoulder to the wheel flange is the same.
 
Cranky said:
Nope, they are equal length....and it wouldn't matter if they were longer because the distance from the bearing shoulder to the wheel flange is the same.
Click to expand...

Ok, thanks Cranky.

I had a '64 Polara years ago and the H/50s on 10 in. rims would rub the wheel well on the passenger side. After the Dana transplant, I had the same clearance in both sides, no more rubbing. I wonder what happened there?
 
If you measure any of these old cars you will find that none are perfect,square,equal, or anything of the sort. Most rear axles are offset 3/4 to the right,dont know if that is plan or coincidence. Stretch a string from front tire to rear on both sides and you will see what it mean. I think you are cutting it too close for production tolerances with that size tire. E body guys can do it but us B body guys are not as fortunate always. If I had the same problem I would go to an alignment shop to check the rear alignment. If it is straight then get narrower tires. Off? ,loosen all u bolts,shim up the forward brackets till the axle is square,then retighten all bolts and see where it lands. Good luck,bro!

- - - Updated - - -

Oh ,the leaf springs are not perpendicular either.
 
You are lucky to have a car that is only 1/8" out from side to side. Nothing is very close. If the car doesn't dog track and no obvious signs of prior frame damage, then you are dealing with production tolerances.
 
I'll throw a couple of cents in here too. Cranky is the expert on this kind of stuff so I agree with what he says, but IMHO 1/4 inch tire clearance is just too damn close. When you get on the car hard or go flying off into a corner, the rear axle is going to move around laterally on the springs in relation to the rear frame. The shackles, bushings, springs and even the frame mounts are going to give a little and with that little clearance I'd be surprised if it didn't rub somewhere. I know that you want to run as big of a tire/wheel as you can but I'd go for a little smaller tire.
 
Moparsmitty said:
I'll throw a couple of cents in here too. Cranky is the expert on this kind of stuff so I agree with what he says, but IMHO 1/4 inch tire clearance is just too damn close. When you get on the car hard or go flying off into a corner, the rear axle is going to move around laterally on the springs in relation to the rear frame. The shackles, bushings, springs and even the frame mounts are going to give a little and with that little clearance I'd be surprised if it didn't rub somewhere. I know that you want to run as big of a tire/wheel as you can but I'd go for a little smaller tire.
Click to expand...

Yea, good point, I have always used 3/4" as a rule of thumb, that may even be a bit close. Until you have shredded the side wall on a $250 tire at speed, you haven't lived.
 
Don't know about being an expert.....maybe an X perv.... :D
 
Thanks to everyone for the feed back on this topic, much appreciated, and once again am learning more then I thought I ever would about rebuilding cars!!!. Anyway, Thanks Cranky you helped me stop and step back and think about things. And thanks to MoparMarks who recommended to talk with Dr. Diff, which I did today, great guy, tons of knowledge, had a great conversation and came to the conclusion that the axle housing measurements are good, with the exception that some mentioned, its not un common to have spring perches off just a bit, but the measurements from the axle shaft flange to the brake plate are both identical, which is a good indicator that the housing is within tolerance of 57 and 7/8 inch length.

So here is the result of what needs to be done, and I'm embarrassed about this first oversight on my part, but I thought I had ordered wheels with 5 inch back space, turns out they are 5.5, so that's just too deep for my setup and the close clearances of the side wall to the leaf spring, and why I was confused as to why it was so close. Most likely I will go back to just having 15x8's all around, which still looks good, but some how I got the idea in my head to cram as big of a wheel on as I could, but screwed up, so will have some new rims for sale soon!!! LOL

Second thing is the passenger side wobble and I will verify this hopefully tomorrow if that axle shaft flange is bent or its something else, but leaning toward the bent flange. That's an easy fix, I can get some brand new shafts, just not sure if I want to go with green bearings or not.

Anyway that's the story thus far!
 
You must log in or register to reply here.

Similar threads

M
Rear leaf spring replacement
Replies
2
Views
2K
Purepony
Purepony
6
8.25 27 spline rear disc conversion problem
Replies
4
Views
1K
1STMP
1STMP
koosh
8 3/4 open diff, both axles rotate freely?
Replies
11
Views
612
MoparMur
MoparMur
1970rt440
1970 dodge charger rt 440 rear leaf springs
Replies
7
Views
2K
R/T Boy 67
R
Rusty knuckles
Rear spring rate
Replies
16
Views
2K
Rennkafer
Rennkafer
Auto Transport Service
Back
Top