So I found the rear end to be almost a quart low as well as it seems my piñon seal is leaking slightly as I can see oil spewed under the bed. I ended up also finding a good amount of play on the driveshaft u-joint Maybe about 1/8”. I pulled the wheels off and started the engine with the rear on Jack stands and watched the axle while in drive. To the naked eye that don’t seem wonky but I’m gonna try and pick up one of those gauges as well. The bearings have minimal play on both sides. Regardless so far both backing plates are gonna need to replacing as I also found the driver side it seems like the bottom of the brake shoes wore through the backing plate which I almost feel like it could cause the shoe to maybe bind up and get stuck possibly.
Use a block of wood and a screw driver firmly attached. See if it goes scrape scrape, but this only tells you about the axle. I think you almost have to have an alignment bar and adapters to check the housing.
Has the rear-end been shortened and/or had any new spring/shock hanger brackets welded to it? (Non-Factory) stuff. Lots of times guys weld brackets onto the housings and the tubes will distort . . . then the bearings wear out really fast as the centerlines of the bearing bores no longer align with the carrier bearings. Most housings need to be straightened or have the bearing ends cut off and rewelded on with an alignment bar in the middle.
More food for thought here.... a drag racing friend has convinced me to never do that thing we all do .... put a floor jack under the pumpkin and drag the whole car around the shop sideways like that. He has seen a perfect axle bend just enough that it had a LOT of drag in it after that was done. The axle tubes are not really meant to hold up the whole back end of the car just by how they are welded to the center section.
WHAT!?!?!?!?!?!?!? That's one of the most ridiculous thing's I've ever heard! What holds up the rear of a car? Oh Yeah... springs between the frame and AXLE TUBES!
Each spring and each END of the axle tubes hold up half of the weight of the back end of the car. If you jack it up by the center section, now the whole weight of the back of the car is placed there and you are putting leverage on the straightness of the axle. If the axle has extra bracing like some of the strong drag cars (hmmm. I wonder why? ...) you are probably OK. I might be tempted to think a banjo rear end with the big center flanges may be stronger in this respect than 60s rears where the tube is welded to the center. That is a much smaller area that would have to carry the weight. I doubted it too at first, but he pointed out using a torque wrench that on a Ford 9" axle that was optimized to spin free through careful assembly later took more force to spin over at the pinion after using a floor jack in the middle. This is a level of detail most folks would never go to or notice, but if you want to go fast, this adds to parasitic drag.
That increase could be the difference between turning the pinion while out of the housing, resting on a workbench vs. bolted in the housing with a slight amount of case distortion. I'm not buying the jack in the center theory.
I did collision work for 45 years and you’d be surprised how little of a hit on a wheel It takes to bend a housing or an axle flange.
I see what I think is the problem,... and it happens alot... people don't even know it till they can't get the axels out...
im gonna say you are spot on...the self taught ,self proclaimed wizards would never listen to me... then when they were done I'd ... now lets see you pull the axel... you can't hot weld all that junk on the tube with out it being in a fixture ... or small welds and cooling as you go...
I fixed one one time by welding a fat bead with an X across the top of the tube. probley got lucky but waas able to slide the axel in... but like said,.. welding all the junk on, most won't even know till it wipes out the bearing...
I gotta say, I don't disagree with the comment above. Due to the leverage factor involved, I can totally see how jacking from the center of a rear end could bend the housing. Not saying it will or it has, I am saying I can see how it could happen. I guess a lot depends on the rear end and the weight of the vehicle but I will NOT say "no way that's possible".
Sounds more like an inferior design, or a poorly built housing. If only there was an Engineer to ask.
Ahhh, dirt track racing and bent axle housings... My son's buddy was running an 80s Monty Carlo with a Ford 9" in the "stock" class at the local dirt track. One race night, he got in a crash. One of the cars went airborne and came down on the trunk of the Monty, just to the one side of the rear axle. You didn't need a gauge to see that 9" was bent bad. He spent the next 4 days looking for a good 9" axle housing and was not having any luck. I told him I could straighten it good enough to work until he found one, but first he was going to have to tell me the current housing was junk and couldn't be hurt any more. He finally admitted it was junk. We pulled the rear end out from under the car, and managed to get the axle out of the bent side. We sat the assembly on jack stands with the bent end hanging off the last stand, with the bent end pointing upward. I handed him the sawzall with a new blade in it and had him cut the bent tube right at the bend, about 1/2 way through. He was a wreck, and kept asking me if this was going to work. I kept reminding him it was already junk and we couldn't hurt it. After the cut was made, I fired up the torch and started heating the bottom part of the housing. .As it started turning red, it also started dropping down. It was a slow heat and watch process, we never applied any force to the housing end. When it looked about straight, I had him slide the axle in and check to see if it turned freely. It took a few rounds, and we were careful not to get the axle shaft or the bearing hot. When we got to the point the axle slid in and turned freely, we pulled the axle out and let the housing cool to the touch. The top of that cut had nearly a 1/4" gap! Then we started the very slow process of welding the gap closed. We would check the axle turning ease with every weld. When we were done, the axle fit very nicely and turned freely. We installed a new bearing, assembled the axle and installed it in the car, after we sort of straightened the car. That 9" lasted the rest of the season. Probably not the recommended procedure, but some times you got to do what you got to do. We must have done OK, a few weeks later, he won the main event for his class.
If you have the rearend removed, stand it up on one of the tires and rotate the housing. If it runs true, the housing is good. If the top wheel moves in a loop the housing is tweaked. The error is multipied quite a bit so I don't know how much is tolerable. Gary
I was able to fix a lot of junk in my welding shop. Didn't take me long to figure out if the guy still thought his broken stuff was still perfect, he was never going to be happy. I had one guy that thought I could weld his part that was broken into two pieces back together, and not hurt the original paint where the weld joint would have been. Even after I explained why, he didn't believe me. I told him I couldn't help him. If your broken part is still good, I'm not the guy you need.
I have narrowed, and/or re-ended probably 200 housings. 1-1/2" solid TGP rod, with precisely machined pucks. I think I remember 3 being in good alignment before I started. Many were 1/4" or so off, sometimes on both sides. One thing that all of these had in common it that they all came out of functioning vehicles, and were not experiencing bearing problems.
A bent tube still won't make the backing plate angled as bad as theses are, you would have some very bad bearing issues if it was.
Welp the rear housing is bent. Anybody in central California have a 67-72 Camaro/chevelle 12 bolt housing laying around? Or know of a shop that will straighten them around central ca? Thanks!
Yep - all that welding on one side of the tube (coil-over hangers) drew the tube toward the welds - so it is way out of alignment. I'm not familiar with your location, so no help from me.
These pictures tell the story. Looking thru the housing you can see the ends are bent down. All that welding on the bottom side of the housing caused the bend. Start with another straight housing, weld those same brackets on, and that "straight" housing will be bent just like the one you have. Thats what welding on tubing does. You can straighten the housing you have or start over with a "straight" housing, and then straighten that "straight" housing that you just bent by welding on it!
Have the housing straightened and depending on how "close" they can get it, have the ends cut off and rewelded back on with a big "alignment bar" that picks up the carrier bearing locations and the outer bearing locations. The welding should be done by somebody who really knows what they're doing.
I’ve called all over my area and seems like no one straightens them these days over here in California.
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