# Replacement of rear axle.



## gtoearl (Dec 21, 2009)

Replacement of rear axle. I have a 1966 Pontiac GTO that appears to have a bent axle. Thought it was the brakes squeaking but further inspection showed the axle bent. I’ve never change the axle before can somebody explain the process. Thanks


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## Mine'sa66 (Oct 30, 2019)

gtoearl said:


> Replacement of rear axle. I have a 1966 Pontiac GTO that appears to have a bent axle. Thought it was the brakes squeaking but further inspection showed the axle bent. I’ve never change the axle before can somebody explain the process. Thanks


Real quick and dirty....assuming it has a BOP rear end in it, that's a bolt in axle. There's a flange floating on the axle between the pressed bearing and the hub. Disassemble the brakes, unbolt the axle flange, then pull the axle out of the housing. You will have to press the old bearing off. Then you can swap the axle flange to the new axle, then press the new bearing on. Then bolt back together. 
I'm sure some of the folks that have service manuals handy will post up pics.


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## gtoearl (Dec 21, 2009)

So what you’re saying is the axle will slip out without taking the cover off the rear end. I’ve heard that there is a C clip of some sort that holds the axle to the gear in the rear end... I have an original 323 limited slip Pontiac rear end.


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## Old Man Taylor (May 9, 2011)

The C-clip is in the Chevy rear ends.


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## Mine'sa66 (Oct 30, 2019)

gtoearl said:


> So what you’re saying is the axle will slip out without taking the cover off the rear end. I’ve heard that there is a C clip of some sort that holds the axle to the gear in the rear end... I have an original 323 limited slip Pontiac rear end.


As OMT said, Chevy rears have that design. Buick,Pontiac,Oldsmobile (BOP) use the flanged setup.


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## Old Man Taylor (May 9, 2011)

The Pontiac way is much better. The C-clip is at the tip of the axle, so it the axle breaks it comes out.


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## O52 (Jan 27, 2019)

Toms Kick Ass axles. Made in USA. 



https://www.tomsdifferentials.com/2011catalog/Pages34-35.pdf





PRODUCTS: Tom's Differentials



I'd replace the bearings on both sides. And measure the Axle length to insure you get the right one


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## PontiacJim (Dec 29, 2012)

Mine'sa66 said:


> Real quick and dirty....assuming it has a BOP rear end in it, that's a bolt in axle. There's a flange floating on the axle between the pressed bearing and the hub. Disassemble the brakes, unbolt the axle flange, then pull the axle out of the housing. You will have to press the old bearing off. Then you can swap the axle flange to the new axle, then press the new bearing on. Then bolt back together.
> I'm sure some of the folks that have service manuals handy will post up pics.


Not too difficult as Mine'sa66 has stated. Not sure if you have to pull brakes or not? Seeing you will be installing a new axle, have a shop install a new seal, bearing, collar and gasket, so you won't have to mess with the bearing/collar on the old axle. At the same time, I would pull the other side and replace the seal, bearing, collar, and gasket.

Here is an earlier forum post that may be of help:









Pontiac Lemans 10 bolt (8.75) axel bearings?


I'm changing out the backing plates on my 72 lemans rear end and I'm just reading now ...that the rear is kind of a red-headed step child of 10 bolts? I'm not looking to change gears or anything crazy, I just want to pull the axels, put new backing plates on and since its apart new axle shaft...




www.gtoforum.com





Here is a basic exploded view, but the Service Manual for your car should have all the info you need to do the job if you have questions.



https://www.tpocr.com/64-72pontrearaxleipc.html


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## 1969GPSJ (Feb 26, 2020)

you can avoid removing the brakes , the flange on the axle has a hole to allow access to the nuts to remove the axle just rotate the axle until all the nuts are removed and out comes the axle


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## gtoearl (Dec 21, 2009)

Thank you everyone for your responses. I feel more comfortable in tackling this project.


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## gtoearl (Dec 21, 2009)

gtoearl said:


> Thank you everyone for your responses. I feel more comfortable in tackling this project.


Here’s a follow-up question for you guys. It may sound a little easy for you to answer I hope. I have a four post hoist in my shop that I built next to my house. I love the hoist but when trying to jack up the car off the hoist to get to the wheels sometimes is a challenge. What procedure would you suggest that I use to lift up the rear of the car and secure it so I can get the wheels off of it to remove the axles .. 

next question is if in fact my axle is bent which I think it is because it runs out a little bit and rubs the brakes on the drum , what in the world do you think happened to cause it to bend... i’m searching my memory over the last year or so and I can’t remember spinning the wheels or doing any burnouts. I noticed the axle running out when I replaced the rear brakes. I double checked my procedure And don’t think it has anything to do with the new brake installation. I noticed it when I put the new drums on and it started rubbing. I’m at a loss to figure out what happened. Any help to solve my mystery would be helpful thank you guys.


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## 1969GPSJ (Feb 26, 2020)

sounds like have twin post lift? 
maybe when you are setting the "pads" make sure to catch the frame and not the rear suspension arms, that may be your problem?unless you have a massive tires on rear


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## gtoearl (Dec 21, 2009)

No it’s nothing like that it’s a drive on four post lift with ramps.


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## 1969GPSJ (Feb 26, 2020)

like this??


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## gtoearl (Dec 21, 2009)




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## Mine'sa66 (Oct 30, 2019)

gtoearl said:


> Here’s a follow-up question for you guys. It may sound a little easy for you to answer I hope. I have a four post hoist in my shop that I built next to my house. I love the hoist but when trying to jack up the car off the hoist to get to the wheels sometimes is a challenge. What procedure would you suggest that I use to lift up the rear of the car and secure it so I can get the wheels off of it to remove the axles ..
> 
> next question is if in fact my axle is bent which I think it is because it runs out a little bit and rubs the brakes on the drum , what in the world do you think happened to cause it to bend... i’m searching my memory over the last year or so and I can’t remember spinning the wheels or doing any burnouts. I noticed the axle running out when I replaced the rear brakes. I double checked my procedure And don’t think it has anything to do with the new brake installation. I noticed it when I put the new drums on and it started rubbing. I’m at a loss to figure out what happened. Any help to solve my mystery would be helpful thank you guys.


I'm assuming your 4 post doesn't have swing jacks? I'd try and center the car best as possible and use jack stands on the frame. May not be wide enough though. 4 post lifts are great, but w/o swing jacks, not really as handy as a hoist. I would assume that it has to do with your brakes. It didn't do this before the brake installation? You didn't bend the axle doing the brakes....
New drums or old? If old, did you mark them where they sat on the flange? They need to go back from whence they came. If you didn't mark them, I'd pull that drum off and rotate it one lug hole at a time and see if you don't solve your problem. Just reread your post...new drums....bet you a big old cup o Joe therein lies your problem. Again, you didn't bend the axle changing the brakes. One of your drums is not sitting flat on the flange. Take a wire wheel/pad sand it smooth. May be able to solve it, may need to replace the offending drum.


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## gtoearl (Dec 21, 2009)

Thank you very much that’s a real good idea. I’m gonna play around with rotating the new drum around the wheel and see if it rotates without a wobble. I know when I finish the brakes and put the new drums on it was doing that so I took the new drum off and put the old drum back on the offending side. It seem to fix it for a bit but then it started squeaking again. I suppose if I take the Drums off with the car jacked up and put the car in gear and watch the end of the axle turning I could tell if it’s got a wobble in it. Anyway thanks very much for the suggestion I’m gonna try that when I get around to it.


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## PontiacJim (Dec 29, 2012)

gtoearl said:


> Thank you very much that’s a real good idea. I’m gonna play around with rotating the new drum around the wheel and see if it rotates without a wobble. I know when I finish the brakes and put the new drums on it was doing that so I took the new drum off and put the old drum back on the offending side. It seem to fix it for a bit but then it started squeaking again. I suppose if I take the Drums off with the car jacked up and put the car in gear and watch the end of the axle turning I could tell if it’s got a wobble in it. Anyway thanks very much for the suggestion I’m gonna try that when I get around to it.


You may be assuming "axle" when in fact it is the "axle tube" that is bent. Axle tubes do get bent and a specialist shop can check for straightness and/or straighten the tube if they are equipped to do so.


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## gtoearl (Dec 21, 2009)

How does an axle tube get bent? Could jack in the car on each end instead of in the middle result in bending a tube?


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## Mine'sa66 (Oct 30, 2019)

gtoearl said:


> How does an axle tube get bent? Could jack in the car on each end instead of in the middle result in bending a tube?


Like anything in life, there's a load of ways to skin a cat. It's not a particularly common event. In your case (drum runout causing interference with brake shoes as I understand it) I would not really be looking for a bent axle tube.


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## Mine'sa66 (Oct 30, 2019)

Mine'sa66 said:


> Like anything in life, there's a load of ways to skin a cat. It's not a particularly common event. In your case (drum runout causing interference with brake shoes as I understand it) I would not really be looking for a bent axle tube.


And, no on the jacking. you can take both wheels off the ground via the center unit or either wheel via one side. That's not going to bend the housing.


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## gtoearl (Dec 21, 2009)

]








Well I got the car jacked up in the wheels off but I can’t figure out how to post a video to show you the wobble on the axle. The passenger side has a little bit of a dance to it and the other side seems to be not doing the same thing.


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## gtoearl (Dec 21, 2009)

Mine'sa66 said:


> Like anything in life, there's a load of ways to skin a cat. It's not a particularly common event. In your case (drum runout causing interference with brake shoes as I understand it) I would not really be looking for a bent axle tube.


But the drum bolts directly on the axle shaft. If the axle shaft is bent the drum is going to have a wobble to it. Such as mine is doing. I got the car jacked up and took a video of both sides To compare the run out. But this forum does not allow videos as I can see. But there is definitely a difference between one side and the other as far is a little bit of a bump or wobble up and down.


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## gtoearl (Dec 21, 2009)

If someone knows how to post a video I would like to do that. If not if someone can give me their email address I’ll send them the video for their opinion. thanks for everyone’s help.


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## BearGFR (Aug 25, 2008)

I too have a 4-post lift. When I need to get the wheels up, I use a pair of low profile bottle jacks that sit on a bridge that spans the two lift runways.
Like this:
BendPak Sliding Jack Platform for Car Lifts 3000-Lb., Model# JP-3 | Northern Tool

Just because you're hearing the brake shoes rub sometimes does not mean you have a bent axle. It can be normal to hear the shoes rub a little intermittently. If the only symptom you have is that, it's nothing to worry about.

To check for a bent axle, put the car up, leave the tire on, put it in neutral (chock the front wheels for safety), raise that rear wheel off the platform (or both wheels if it has a limited slip diff), slowly rotate the suspect side while you've got some sort of marker next to the outside tire sidewall. It can be something as simple as a small cardboard box sitting on the lift runway next to the tire. If you've got any wobble in the wheel as it turns, you'll be able to see it. No wobble, no bent axle. 

Almost always, you'll also be able to feel a wobble when you're driving the car. It'll be a vibration you can feel that varies in sync with speed. 

Bear


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## Mine'sa66 (Oct 30, 2019)

gtoearl said:


> But the drum bolts directly on the axle shaft. If the axle shaft is bent the drum is going to have a wobble to it. Such as mine is doing. I got the car jacked up and took a video of both sides To compare the run out. But this forum does not allow videos as I can see. But there is definitely a difference between one side and the other as far is a little bit of a bump or wobble up and down.


The drum doesn't bolt to the axle. It floats on the flange. Since this issue only arose after changing the brakes, the problem isn't likely to be a bent axle. As I mentioned before, the odds are the drum isn't sitting flat on the axle flange. This is super common. It's usually just an imperfect surface on the flange, which you can correct with some emery cloth or wire wheel. It could be an issue with the drum or even the back of the wheel. Much less common, but possible is the backing plate is bent, but again, unless you bent it changing the brakes (like by prying on it to get a drum off) not real likely. Have you swapped the drums from side to side?


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## gtoearl (Dec 21, 2009)

BearGFR said:


> I too have a 4-post lift. When I need to get the wheels up, I use a pair of low profile bottle jacks that sit on a bridge that spans the two lift runways.
> Like this:
> BendPak Sliding Jack Platform for Car Lifts 3000-Lb., Model# JP-3 | Northern Tool
> 
> ...


thanks very much for the comment Bear. I will definitely try your suggestion on figuring out if I really do have a bent axle. As I said in my prior comment I am not able to post a video to show the wobble in the Axel. If you know a way to post a short video for that let me know or if you are able to give me a contact email I’d love to send it to you for your opinion. I think I will buy myself a couple small bottle jacks and I will be jacking it up on the actual as the jacking played does not reach the frame rails. I was thinking of fabricating a long jacking plate that I could put across the bottle jacks to reach the frame. Not sure if it’s necessary or not please advise. Thanks again for all your help.


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## gtoearl (Dec 21, 2009)

Mine'sa66 said:


> The drum doesn't bolt to the axle. It floats on the flange. Since this issue only arose after changing the brakes, the problem isn't likely to be a bent axle. As I mentioned before, the odds are the drum isn't sitting flat on the axle flange. This is super common. It's usually just an imperfect surface on the flange, which you can correct with some emery cloth or wire wheel. It could be an issue with the drum or even the back of the wheel. Much less common, but possible is the backing plate is bent, but again, unless you bent it changing the brakes (like by prying on it to get a drum off) not real likely. Have you swapped the drums from side to side?


I wish I could post a short video I took because the axle definitely looks like it has a wobble when I point the phone right at the axle coming out you can see the wobble. If you know how to post a video on here please let me know I’d love for you to see it and get your opinion. If you have a contact email you can share I can send it that way I guess. I understand now what you’re saying about the wheel being attached to the plate... I will do some more investigating and see if the plate is the culprit here. But again if you could look at my video I think that would clear things up a bit. Thanks very much for your input. It’s a nagging issue I’ve been wanting to repair for sometime.


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## Old Man Taylor (May 9, 2011)

One way to do it is to put the video on YouTube, and then post the link here.


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## gtoearl (Dec 21, 2009)

Hope this works. One is a video of one axle with a wobble in it. The other is the other actual that seems to be running true.


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## Old Man Taylor (May 9, 2011)

I don't know how it could happen, but your axle flange definitely looks like a problem. Time for a new axle.


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## Mine'sa66 (Oct 30, 2019)

gtoearl said:


> Hope this works. One is a video of one axle with a wobble in it. The other is the other actual that seems to be running true.


I see what you're looking at. It's really impossible to tell from that video what's going on. You need a fixed point of reference in the frame. 
Is there any play in the wheel bearing? Grab the axle flange and try and lift it up and down. Bolt a wheel to it and try it so that you get more leverage. Just looking at it, even though I see what you're seeing I would still say it's mostly optical illusion and runout in places where it doesn't matter; I.E. the outside of the axle flange looks like it's moving in an ellipse, but since the outside of the flange isn't necessarily a circle, it makes it look like the axle is bent. Assure no play in the bearing, then get a fixed point next to right where the axle exits the tube. Before I spent a whole lot of time on a bent axle, I would swap the drums and see. I'd probably disassemble the brakes, lube up the backing plate well, then carefully reassemble.
Bent axles are out there, but there was usually a memorable event that preceded them. Also, I'm stuck on it didn't do this before some brake parts were changed?


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## gtoearl (Dec 21, 2009)

When I grab a hold of the axle flange and jerk it in and out there is play in it going in and out.


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## gtoearl (Dec 21, 2009)

Old Man Taylor said:


> I don't know how it could happen, but your axle flange definitely looks like a problem. Time for a new axle.



Do you think the flange is bent..? There is play in the axle when I pull it in and out. It pops in and out.


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## Mine'sa66 (Oct 30, 2019)

gtoearl said:


> When I grab a hold of the axle flange and jerk it in and out there is play in it going in and out.


End play is normal on most rears. We have determined that this is a BOP rear correct? If so, I don't think you want any end play. The wheel bearing is pressed onto the axle, so the axle cannot move inside the inner race like a chevy rear. If you have end play, either the press fit is no longer, the bearing is moving inside the axle tube, or the retainer flange is not tight, or ???. Most of which could give you the runout you're seeing. Losing the press fit is bad, that's the only thing holding it in. No play at all up and down? Pull real hard outward, you need to know for sure. What's the other side do?


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## gtoearl (Dec 21, 2009)

Mine'sa66 said:


> End play is normal on most rears. We have determined that this is a BOP rear correct? If so, I don't think you want any end play. The wheel bearing is pressed onto the axle, so the axle cannot move inside the inner race like a chevy rear. If you have end play, either the press fit is no longer, the bearing is moving inside the axle tube, or the retainer flange is not tight, or ???. Most of which could give you the runout you're seeing. Losing the press fit is bad, that's the only thing holding it in. No play at all up and down? Pull real hard outward, you need to know for sure. What's the other side do?


 What is BOP? I have a Pontiac limited slip 10 bolt 3:23 rear end . I will post another video today with me pulling the axle in and out and up and down. Thank you very much for sticking with me on this. Both of you!


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## gtoearl (Dec 21, 2009)

There’s a short video of me inspecting the offended side the side I think is running out. Bear with me I’m going slow here.


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## gtoearl (Dec 21, 2009)

Now this is a video with the side that I suspect is an issue. I put the new drum I had sitting in the shop but you will notice that it has three counterweights on it which is kind of unusual. And you can see in the video how it’s running out of round. I will get to the shaft in another video and show you the play in it. Again bear with me I’m going slow.


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## gtoearl (Dec 21, 2009)

Now here is a video when I switch the drums. Putting what I called a good drum On the axle that I suspect is bent. You can see in the video there is no run out now it has been cleared. Again I will be looking at the play in the axle after I’m done with this.


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## gtoearl (Dec 21, 2009)

And here is a video of the drum that has all the counterweights on it installed on the side that I suspected not being bent. I have now created the run out.


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## gtoearl (Dec 21, 2009)

Anyway there was Several videos I loaded for you guys to watch. I hope I didn’t bore you! LOL I am a little confused in the whole issue. Like I said I will take the drums off now and take a video of the play in the axle on both sides.


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## Mine'sa66 (Oct 30, 2019)

gtoearl said:


> And here is a video of the drum that has all the counterweights on it installed on the side that I suspected not being bent. I have now created the run out.


Good for you! 1 new drum and you're golden.


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## Mine'sa66 (Oct 30, 2019)

I thought I mentioned it in an earlier post...when you hear BOP that's Buick/Olds/Pontiac. It's a quick way of saying "GM, but not Chevy"


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## gtoearl (Dec 21, 2009)

Well here’s the two videos of me pulling on the axle shafts. Ironically the one that I thought was good actually has more play. Anyway I think you guys have enough to give me a good idea what I need to do. Thank you very very much for the patience and understanding.


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## gtoearl (Dec 21, 2009)

Mine'sa66 said:


> Good for you! 1 new drum and you're golden.


I’m thinking I might be good with one new drum. But after pulling on the axle shafts and hearing them click in and out I’m not sure


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## Mine'sa66 (Oct 30, 2019)

gtoearl said:


> Well here’s the two videos of me pulling on the axle shafts. Ironically the one that I thought was good actually has more play. Anyway I think you guys have enough to give me a good idea what I need to do. Thank you very very much for the patience and understanding.


All you need to do is replace one bad drum. The runout is following the 1 bad drum. As far as the endplay goes,. As I mentioned, end play is normal, On a Chevy rear, the axles are held in with c clips, and the bearing is fixed in the housing. So the axle is free to move a small amount. With the bearing pressed to the axle in a BOP type, I worry endplay might be a problem. I hope other's might chime in and tell me if I'm overthinking it.


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## Old Man Taylor (May 9, 2011)

Mine'sa66 said:


> All you need to do is replace one bad drum. The runout is following the 1 bad drum. As far as the endplay goes,. As I mentioned, end play is normal, On a Chevy rear, the axles are held in with c clips, and the bearing is fixed in the housing. So the axle is free to move a small amount. With the bearing pressed to the axle in a BOP type, I worry endplay might be a problem. I hope other's might chime in and tell me if I'm overthinking it.



I agree.


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## gtoearl (Dec 21, 2009)

So you guys think I should pull both axles. Inspect them, and probably new bearings and seals. In the machine shop should be able to tell me if I have a bent axle.


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## gtoearl (Dec 21, 2009)

I’m not sure how the bearings sits inside the shaft. Is it pressed in there or is it pressed on the axle shaft?


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## Mine'sa66 (Oct 30, 2019)

gtoearl said:


> I’m not sure how the bearings sits inside the shaft. Is it pressed in there or is it pressed on the axle shaft?


The wheel bearing is pressed onto the axle shaft. There is a retainer plate that is trapped in between the axle flange and the bearing. The retainer plate is bolted to the axle housing, thus holding the axle in place. This is why you do not have to open the differential cover to pull an axle on a BOP type. On a Chevy type, the wheel bearing is installed in the housing and the axle passes through it and is captured in the differential via c-clips.


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## gtoearl (Dec 21, 2009)

So not to be redundant, LOL, given I have this in an hour play in the axle shaft, in your opinion that is not acceptable and there is something going on with the axle bearing. So like I said before and you indicated a little I think, I should pull both axles and probably replace the bearings and seals and maybe even the retainer plate...

So you guys are thinking the play in the axle is not acceptable. And believe me I’m not questioning your knowledge or experience but when I bought this car 10 years ago it had a new rear end iand new transmission or rebuilt I should say. Now I suppose they could’ve just put the same axles with bearings back in it but I would think they would replace it at that time. The car was sitting for two years while it was getting painted.. And sitting through the winters not being driven, and I had two motors that I rebuilt in it so there were some downtime there. I guess what I’m asking is, if the car is been sitting a lot could it dry up those bearings and caused them to fail causing the in and out movement.


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## Mine'sa66 (Oct 30, 2019)

gtoearl said:


> So not to be redundant, LOL, given I have this in an hour play in the axle shaft, in your opinion that is not acceptable and there is something going on with the axle bearing. So like I said before and you indicated a little I think, I should pull both axles and probably replace the bearings and seals and maybe even the retainer plate...
> 
> So you guys are thinking the play in the axle is not acceptable. And believe me I’m not questioning your knowledge or experience but when I bought this car 10 years ago it had a new rear end iand new transmission or rebuilt I should say. Now I suppose they could’ve just put the same axles with bearings back in it but I would think they would replace it at that time. The car was sitting for two years while it was getting painted.. And sitting through the winters not being driven, and I had two motors that I rebuilt in it so there were some downtime there. I guess what I’m asking is, if the car is been sitting a lot could it dry up those bearings and caused them to fail causing the in and out movement.


At this point, from however many miles away, I would buy a new drum. Verify the fluid in the differential is full, and drive it.


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