Axle flange bent?

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Madison, WI
My Car
1971 Mach 1 w/408C stroker
So I am in the middle of installing a rear disk brake conversion. While I was at it, I removed the axles and took them to a shop so they press new bearings. Brought the axles back home and installed them. On the passenger side I installed the disc and see that it wobbles slightly while I turned it. Took the disc to the other side and seem pretty straight. I checked to make sure the surface of the flange is clean and with no damage. All checked okay. I took a dial gauge and measured the left-to-right displacement of the flange near the OD. Evidently the flange is bent or something is not right. The measurement was about .017 of left-to-right displacement when I rotate the flange. Could the flange have been bent at the shop when installing the new bearings? I assume that if the flange was this bent when I had the drum brakes I would have noticed some vibrations, but maybe not. Can this "bent" be fixed or do I need knew axle?

 
I had a bent flange on my green car, And yes your right it creates a wobble you would have felt when driving. Checking the receipts from the p.o. I see a bill for new axle bearings and pressing them on. SO who ever pressed on the bearings damaged the flange very easy to do if your not careful. Had to buy a new axle and new bearings. YOU HAVE TO STRESS TO THE SHOP TO BE CAREFUL !!! pressing on the new bearings.

 
I had a bent flange on my green car, And yes your right it creates a wobble you would have felt when driving. Checking the receipts from the p.o. I see a bill for new axle bearings and pressing them on. SO who ever pressed on the bearings damaged the flange very easy to do if your not careful. Had to buy a new axle and new bearings. YOU HAVE TO STRESS TO THE SHOP TO BE CAREFUL !!! pressing on the new bearings.
+1 What Q said. I have seen 8" and 9 " axle flanges bend when installing the bearings. If the guy installing them does not fully support the flange when pressing or if it goes on crooked it can easily bend with the power of the press. I would contact whoever installed the bearings and ask a few questions.

 
Do you think that the flange can be repaired or I am better off finding a new one? If going the "new" route, should i replace both sides or just the one? The other side looks good.

1971 M-code Mach 1

 
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You can look at your brake drum to see if it has a "wobble" wear pattern. If you go back to the shop that bent it I would take both drums along as proof that it was straight before they worked on it.

It's possible to straighten it, but not easy to get it within acceptable tolerances. You never know, they may have even bent it worse and tried to straighten it. I would recommend replacement.

If you're just going for a stock replacement axle, the one side is good enough. If you're upgrading to better quality, then get both.

 
Do you think that the flange can be repaired or I am better off finding a new one? If going the "new" route, should i replace both sides or just the one? The other side looks good.

1971 M-code Mach 1
Very easy to see if it's damaged, Jack the rear up- remove drum- start car put in low and observe the flange, if's its bent you will see it. I've never seen one repaired that runs true plus the cost to attempt can end up costing just as much or more than a new axle. I replaced both on my car you may have a hard time finding a single new one since superior axle went out of biz. Moser makes them but in pairs only https://www.summitracing.com/parts/msr-a28-71must/overview/year/1972/make/ford/model/mustang

And they say estimated delivery 7/19

I wouldn't buy used ether UNLESS you can see it spin verify it's true.

Make sure to also verify length and splines

 
Pressing the bearings on should not have bent the axle. I only use the press with bearing clamp to remove them then a long piece of pipe to slip over the axle to press only on the inner race and the retaining ring when putting new one on. It does not take much to press them on not really tight. They also just slide a couple parallels under the bearing and press. I have had Ford 9" axle bearing work their way off under heavy loads. I have changed them without even having a press they are not that tight.

You can take to someone with a lathe, press out your wheel studs and have them face the axle between centers. I would not just chuck up on the axle and turn that is not how they were made originally. There are center drills in each end of the axle and you put between centers on a lathe and use a drive dog to rotate it. Might have to clean the outside center drilled hole up due to rust inside is in grease and should be good.

I have had to face mine on a couple cars due to sliding into curbs during autocross runs. .015" - .020" won't be noticed on the wheel position drum or disc.

One of the axles on my F-150 is bent now where my daughter hit trees and a culvert. Had to cut front spring hanger off and put another on was folded up. I never bothered to face axle you don't feel it in the ride and I have driven 25,000 miles since the accident with no tire issues. Too much trouble to get the axles out of the new ones. Wheel is also bent when they put new tires on they showed me on balance machine. It is a work truck not going to worry about it. I do take on long hauls picking parts and pull dolly and trailer.

Heck I turned a maverick up on the two drivers side wheels the second day I owned it. Slid into a traffic island popped the car up on two wheels went a ways and it dropped back down. Had to get two new wheels, new hub caps and trim rings, face the axle and chain the car down and pull the rear back in alignment to keep it from dog tracking, lol. Those were the days.

It is a car not a space ship.

While you have them out if you hot rod any you might want to wash all the grease off the two axles. Mask off a line from end to end on the axle and paint with white paint. The next time you pull them you can tell if the axles are twisting if the line is not straight.

 
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I did my own using a press. I'm not a professional machinist or mechanic or even someone employed by a professional machinist or mechanic, and I cannot for the life of me understand how someone can get it so wrong that they bend an axle flange.

I'm not saying it can't or doesn't happen... I just don't get how someone can mess up so monumentally bad that an axle flange gets bent ahead of a bearing cage. I mean, the axle flange basically holds up the weight of its part of the car when just sitting there, and is subjected to many, many times that in the way of the forces they endure driving down the road, turning, bouncing through imperfections in the road, etc. The bearings require less than 2 tons of force to install them properly.

 
I talked to the guy that worked in my axle. He explain me the process and he doesn't use the flange to apply any force. Based on his description it seems hard that it could happen at the shop. It will be hard to prove.

The flange wobbles about 0.015", which I measured with a dial indicator. It seems that I need a new axle, but before that I will try the hammer method since I don't have much to lose. The shop offered to press in the new bearing at no charge.

 
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I would take a look at the axle shaft. If it is bent it will cause the flange to wobble. You can put it on a couple of v-blocks and rotate it to see if it is straight. It's relatively easy to straighten one in a press.

 
It's not the bearing that's hard to get on but the retaining ring. I've always cut them and the old bearing off if just replacing on a old axle. Install is made much easier by putting the axle in the freezer for 48 hours prior (if you can) The bearing will usually push right on. The retaining ring I heat up in the toaster oven prior -pull the axle out of the freezer the ring out of the oven and no press required.

 
I would take a look at the axle shaft. If it is bent it will cause the flange to wobble. You can put it on a couple of v-blocks and rotate it to see if it is straight. It's relatively easy to straighten one in a press.
I put the dial gauge on the axle and i got about .004" and that was with no much cleaning.

1971 M-code Mach 1

 
It's not the bearing that's hard to get on but the retaining ring. I've always cut them and the old bearing off if just replacing on a old axle. Install is made much easier by putting the axle in the freezer for 48 hours prior (if you can) The bearing will usually push right on. The retaining ring I heat up in the toaster oven prior -pull the axle out of the freezer the ring out of the oven and no press required.
And my wife wont allow me in the kitchen anymore after that.... which may be a good thing anyways.[emoji1] [emoji1] [emoji1]

1971 M-code Mach 1

 
I ended up getting two axles from Don from one of his parts cars. The lateral runout at the axle flange is about 0.004" and about 0.005-0.010" at the disc brakes (1/2" from outer edge). The runout measurements at the discs are highly dependent on how the nuts are tightened. I got different measurements every time I tried. I think these measurements are good enough. We will see when I drive the car if I get any bad vibrations, but all said, looks much better than what I had with my old axles.

One thing I noticed is that the bearings in my old axles seemed not to have been press all the way. After pressing the new ones they were about 1/4" closer to the flange, which matched the bearing on the used one from Don. However, I don't know if it is possible to "under" press the bearing. When I took the measurements on the old one I was not paying that much attention, and I can't remember for sure if I measured to the inside bearing track, so I can't confirm this 100%.

Thank you Don for your help and finding those axles for me. It was a pleasure doing business with you.

 
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