How to tell if rear axle housing bent?
03-12-12, 10:18 PM
#1
How to tell if rear axle housing bent?
Previously I have had a really bad negative camber issue on the left rear. If anyone is familiar with my build thread I posted pictures of my left rear lower control arm. It was bent, although not sideways but rather up as if the car had bottomed out previously sometime before my ownership. I am thinking now that this bottoming out may have caused a bend in the axle housing.
I previously replaced my rear wheel bearings and actually had to replace the left axle since the bearing had failed so badly (didnt make any weird noises that I could tell) that the inner part of the bearing actually cut a groove in the axle where it meets. I replaced the bearings because of the camber issue, thinking maybe the bearing was bad.
I replaced all that stuff (bearings, wheel cylinders, brake shoes) last year and noticed after driving for a couple hundred miles that the left tire was better but not "perfectly straight" like the right side. I have compared my rear tires to 4 other FBs form different years and there is definitely something wrong. I am thinking that the lower control arm wouldnt cause this even if it were seriously bent which mine was not.
OK so enough of the back story. Main question - is there a way to measure or be able to tell if the left axle housing area is bent up? Can you do it while rear end is installed? I currently have most of my rear unhooked and hanging it honestly would be that big of a deal to take it the rest of the way out, but if I can check it while still installed I would prefer that. Thanks for any help or ideas.
-IanS
Oh BTW those not familiar with my car we are looking at an 83 open rear with an 82 LSD and driveshaft installed. I actually prefer this setup as I dont have to mess around with my perfectly fine working drum rear brakes (dont have to add or change brake lines, etc). In fact, if I do have to replace rear I will look for an S2 rear end housing and swap all my stuff into it, mainly because I know its all good and works properly and an open rear is MUCH easier to find and also MUCH cheaper to buy.
I previously replaced my rear wheel bearings and actually had to replace the left axle since the bearing had failed so badly (didnt make any weird noises that I could tell) that the inner part of the bearing actually cut a groove in the axle where it meets. I replaced the bearings because of the camber issue, thinking maybe the bearing was bad.
I replaced all that stuff (bearings, wheel cylinders, brake shoes) last year and noticed after driving for a couple hundred miles that the left tire was better but not "perfectly straight" like the right side. I have compared my rear tires to 4 other FBs form different years and there is definitely something wrong. I am thinking that the lower control arm wouldnt cause this even if it were seriously bent which mine was not.
OK so enough of the back story. Main question - is there a way to measure or be able to tell if the left axle housing area is bent up? Can you do it while rear end is installed? I currently have most of my rear unhooked and hanging it honestly would be that big of a deal to take it the rest of the way out, but if I can check it while still installed I would prefer that. Thanks for any help or ideas.
-IanS
Oh BTW those not familiar with my car we are looking at an 83 open rear with an 82 LSD and driveshaft installed. I actually prefer this setup as I dont have to mess around with my perfectly fine working drum rear brakes (dont have to add or change brake lines, etc). In fact, if I do have to replace rear I will look for an S2 rear end housing and swap all my stuff into it, mainly because I know its all good and works properly and an open rear is MUCH easier to find and also MUCH cheaper to buy.
03-13-12, 09:29 AM
#3
This is just thinking out loud, but seems like the thing to try to measure is if your axle faces are parallel:
Lift the rear and take off the rear tires, and then tightly affix a long (maybe 2 feet) rigid straight-edge flush to the face of each axle end, parallel to the ground. (A pair of 2-foot beam bubble levels would be perfect).
Carefully measure a fixed distance along the beam front and rear from the axle face, and mark that point.
Then use an accurate tape measure to measure the distance across the vehicle between the front marks, and between the rear marks.
If the two measurements are equal, your axle faces are parallel to each other, which in turn would imply that your axle carrier is straight in the horizontal plane.
To check the vertical plane would be harder, since the car is in the way above the axle, but you could probably infer it by rotating the straight beams vertically and looking for a difference in the measurement across the bottom versus the horizontal measurement.
You could use a pair of rims without tires instead of the straightedge, if you have some, but trying to measure from the tire would ruin the accuracy of the measurement, tires being flexible and all.
Lift the rear and take off the rear tires, and then tightly affix a long (maybe 2 feet) rigid straight-edge flush to the face of each axle end, parallel to the ground. (A pair of 2-foot beam bubble levels would be perfect).
Carefully measure a fixed distance along the beam front and rear from the axle face, and mark that point.
Then use an accurate tape measure to measure the distance across the vehicle between the front marks, and between the rear marks.
If the two measurements are equal, your axle faces are parallel to each other, which in turn would imply that your axle carrier is straight in the horizontal plane.
To check the vertical plane would be harder, since the car is in the way above the axle, but you could probably infer it by rotating the straight beams vertically and looking for a difference in the measurement across the bottom versus the horizontal measurement.
You could use a pair of rims without tires instead of the straightedge, if you have some, but trying to measure from the tire would ruin the accuracy of the measurement, tires being flexible and all.
03-13-12, 11:08 AM
#4
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i like that idea, glenn. we've had practice but when we went to go put the front end together on the race car, we just put a jack handle on the tire and eyeballed it parallel to the rocker. surprisingly when we put the toe plates on it, it was right!
03-13-12, 11:23 AM
#5
That is a good idea Glenn thank you. It seems the easiest/best way to measure what I need to measure may involve just taking it out and going from there. This will suck really bad if it is bent. Sourcing an S2 open rear locally may be difficult, whereas I have an S3 open rear in the parts car. Of course then I would have to buy an LSD for it which would probably cost more than the open, let alone buying new axle bearings (because I might as well). Ugh...
03-13-12, 03:56 PM
#6
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That is a good idea Glenn thank you. It seems the easiest/best way to measure what I need to measure may involve just taking it out and going from there. This will suck really bad if it is bent. Sourcing an S2 open rear locally may be difficult, whereas I have an S3 open rear in the parts car. Of course then I would have to buy an LSD for it which would probably cost more than the open, let alone buying new axle bearings (because I might as well). Ugh...
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03-13-12, 05:45 PM
#8
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03-13-12, 10:08 PM
#9
Well I checked everything earlier and using my ~2 ft straight edge I found there was definitely a difference. Not sure if I would be able to bend it all back straight enough. I dont really feel comfortable with that. Now I am on the lookout for an S2 open rear end assy or just the housing itself.
03-14-12, 03:09 AM
#10
you can straighten it with a torch. Back in the day we used to put negative camber in the rear end by heating the top with a torch until it was red hot and then letting it cool. It would draw the metal. You should be able to use this affect to straighten a bent housing. also you can by a fairly cheap digital level @ Home Depot that will help check the ends of the housing to determine how straight or crooked they are. IMO you may as well try it, wont cost anything to try.
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