Straightening a 8.75 rear end

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3402

3402

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What kind of luck can I expect on straightening a 8.75 rear end.
'71 duster 42 years of being a race car, put back on the street about 5 years ago, with ladder bar rear end. not sure if it was the years of racing or the last 5 of street use (probably 400 miles) . The passenger side end has a measureable bend forward and down. I was looking for a dana, when I found someone who said he might be able to straighten it, Although he hasn't actually seen it. Will look at it this Sat. I guess he has a large fixture and jig. Just wondering what kind of success rate there is on something like this.

Thanks
 
I straighten all kinds of axle housings, Dana, 8.8, GM , 8.75

Straightening housings requires the jig to find the problem and then a press to press it accordingly to the bend.
Some housings are bent at the end, some at the middle of the tube and some at the center-section out.
All depends on the cause when it's looked at.

Yours sounds like it bent after the ladder bar link location from lack of a brace, which is common when people put links on the housing they always do it inboard rather than keeping it as close to the end as possible.
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Would it be worth it to remove the offending tube altogether, and just replace it with new straight tubing? Seems like it would be tough to get the bearing housing back in line after it was bent.

I'm not doubting Supershafts one bit, I'm just trying to visualize the process in my head.
 
He told me as part of the fix, he sometimes has to cut off the ends and reweld them. I noticed the ladder bar mounts aren't quite as lined up as they used to be, so maybe there is some twist as well. Also my right ladder bar mount has an oil leak :).
But anyway, as long as it might be possible to fix it, even if it only buys me another year or two, I'll probably try it. Til I can find a deal on a dana.
Thanks Guys.
 
Supershafts said:
I straighten all kinds of axle housings, Dana, 8.8, GM , 8.75

Straightening housings requires the jig to find the problem and then a press to press it accordingly to the bend.
Some housings are bent at the end, some at the middle of the tube and some at the center-section out.
All depends on the cause when it's looked at.

Yours sounds like it bent after the ladder bar link location from lack of a brace, which is common when people put links on the housing they always do it inboard rather than keeping it as close to the end as possible.
.
Click to expand...

I'd guess the bend starts at the mount (the one leaking oil) In the past when changing rod ends, the bolts would slide in, this last time, it took some preload to get the holes to line up. What kind of brace would I use to help with this problem? Also the coilover mounts are welded to the back of the housing. Thanks.
 
I had my 8-3/4 housing straightened via hydraulic press by a guy in PA and ultimately the housing ends welded on center by Moser when I had it narrowed. The pictures show the rear end with back brace and installed jig (I now own that jig) which shows the orientation of housing ends to the 3rd member axle centerline. They can definitely be straightened:
 

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Thanks guys, now that I know it can be done, I feel a little better going this route. he's going to look at it tomorrow. If he can save it, probably add some bracing as well.
 
3402 said:
I'd guess the bend starts at the mount (the one leaking oil) In the past when changing rod ends, the bolts would slide in, this last time, it took some preload to get the holes to line up. What kind of brace would I use to help with this problem? Also the coilover mounts are welded to the back of the housing. Thanks.
Click to expand...

Most cases with the link attachments that is where they bend and it needs to be straightened there out
I have all kinds of different pieces to hold housings in different spots to straighten them where the bend has initially started.
Once it's straight then you can have a brace put across the housings and then redo any shock mounts.

Any housing can be done, its all on the shop and there ability.


DC 340 said:
I had my 8-3/4 housing straightened via hydraulic press by a guy in PA and ultimately the housing ends welded on center by Moser when I had it narrowed. The pictures show the rear end with back brace and installed jig (I now own that jig) which shows the orientation of housing ends to the 3rd member axle centerline. They can definitely be straightened:
Click to expand...


Thats still off as you can see in the picture. The problem you have with using that tube as jig and not a specific solid bar is that the tube will also move with heat like the tubes in axle housings move.
If you look at your pics the one side needs to go forward and up slightly and the other side needs to go forward and down, if the tube inside is still truly perfect.

The tube will move, i deal with tubes and heat all day it doesn't take much heat to get them to start moving.
 
Just got off the phone with the guy checking the rear end, much to his amazement , he said the rear end checks out almost perfect, said he hasn't seen one this good in a long time. Unfortunately this means I have a problem somewhere else. As the rear end wasn't square in the car. The ladder bars were the same length, but the rear was at an angle to the car. Guess I have to take a closer look at the mounts, and get measurements.
 
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