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Discussion Starter · #1 ·
Okay, this is a weird one because I have not experienced any of the symptoms of a bent axle shaft or axle tubes. Most people talk about crazy vibrations, wheel wobble, brake grind, etc. and my car doesn't experience any of that.
Now I mean, I do have a small squeak going on in the rear under 25 MPH, but that happened right after installing my FRPP one piece driveshaft, so I am contributing the squeak to that.

I have an alignment sheet that will show where my area of concern is:

Font Machine Advertising Rectangle Symmetry


Now the rear specs are swapped. Goofy alignment shop messed up the sheet (as well as the entire front alignment by refusing to listen to my requests on toe, messing up the steering wheel angle and not adjusting camber but taking my money for it anyway). I know this because when I measure camber with my digital angle finder, it shows the specs are the opposite on each wheel from what the sheet reads. Between 89.3 - 89.6 degrees on the angle finder on the passenger, and 90.0 - 90.2 degrees on the driver. Slight discrepancy in readings, but still gives me a good idea on which side really has the negative.
It is also visibly evident when you look at the rear of the car. The passenger wheel is angled in (negative) and the driver side wheel looks like it belongs on a truck (positive).

Automotive tire Tire Mode of transport Wood Floor
Automotive tire Automotive lighting Tire Automotive design Tread


It may be hard to tell by these photos, but if you look at the tires, specifically the top of the tires, it looks like the passenger side is just slightly negative with a hint less toe out then the driver side, which appears straight up or slightly positive with a tad more toe out. It may be me going crazy. But it just doesn't seem right. Like visibly in person I can see they don't match.

Now if this was from manufacturing back in 2007, whatever. I get it, Solid Rear Axle. Gotta deal with it. But it wasn't. The first alignment I got (from a very reputable shop) the sheet read pretty factory-like numbers at -0.2 degrees of camber on the driver side and 0.0 degrees on the passenger side. And the visual angle of the wheels backed that up. They were both pretty much straight upwards.

I only noticed this change in angle slightly after hitting a large pothole that bent my K-member backwards by 3/8" on the passenger side. And really started wondering about it as a potential issue after seeing the new alignment sheet. Is it possible I could've shifted my axle housing or twisted a tube at the same time? I did hit that pothole pretty hard. But wouldn't it required a ton of force, like having the rear end drop off a two foot ledge to bend the axle enough to cause -0.6 degrees of camber? Something just doesn't seem normal.
A discrepancy of 0.8 degrees of camber seems like a little too much to just be okay with, especially on an SRA. Certainly my handling is taking a hit. Especially since Beavis at that [unnamed] shop I went to didn't fix the front camber. So now I have a side to side difference of 0.5 degree in the front and 0.8 in the rear. That can't be doing me any good in the corners.

I'm only bringing this up now because I keep fighting myself on saving to buy a reman rear axle assembly to get rid of this problem, especially since my car's at 192,500+ miles and the rear end has probably never been touched by previous owners. Just get rid of it and have an entire rear axle assembly that'll last another 200K hopefully. But I'd rather not spend $2,000 all said and done if I don't have to. Especially because I'm already looking at having to do a full body paint job, replacing my front subframe and control arms and doing a good portion of engine internal replacements because of the high mileage. So, if anyone is able to help, and save me from spending 2 grand if I don't have to, how would I go about determining if one of my axle tubes is really bent? And is there a fix if one of the tubes is bent? Are you able to take the tubes out? I know some people have the tubes welded to the "pumpkin", but how would I go about straightening the tube before welding it?

Any help is appreciated. And thanks if you read the post in its entirety. I know it's long, as all of my forum posts usual are. Haha.
 

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Back in the day Ford rear axle pumpkins were pressed steel, tapered and welded to the axle tubes. This made them very strong and it was common practice to jack up the rear of the car using a floor jack on the pumpkin. When they went with a cast pumpkin and pressed in tubes it made it unwise to lift the car that way, but that didn't stop people from doing it... That is the likely cause of your poor real wheel alignment.

You can park the car on a level surface and measure each tube with a digital level- that will give you some idea if they are straight in the vertical direction. You can also use the level in a vertical position against the outer wheel flanges.

For the horizontal direction you can use a laser measuring tool, and measure from a fixed point in the front center and to both ends of the rear axle tubes.
 

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Discussion Starter · #3 ·
Back in the day Ford rear axle pumpkins were pressed steel, tapered and welded to the axle tubes. This made them very strong and it was common practice to jack up the rear of the car using a floor jack on the pumpkin. When they went with a cast pumpkin and pressed in tubes it made it unwise to lift the car that way, but that didn't stop people from doing it... That is the likely cause of your poor real wheel alignment.

You can park the car on a level surface and measure each tube with a digital level- that will give you some idea if they are straight in the vertical direction. You can also use the level in a vertical position against the outer wheel flanges.

For the horizontal direction you can use a laser measuring tool, and measure from a fixed point in the front center and to both ends of the rear axle tubes.
Well son of a gun. I wish I would've known that, and should probably inform my dad, as he has a '14 GT.

I've always jacked up the rear of the car by the pumpkin. Even now with the Whiteline sway bars, I use a block of wood on the jack to compensate for the low clearance of the bar, and lift by the pumpkin.
I've been doing this since I bought the car though. And I just now noticed this problem shortly after hitting that massive pothole and taking it to a shop to get the measurements. Wouldn't it have messed up way before? Or could it have just weakened the tubes to the point where hitting a pothole was enough to bend it?

Now, like I said, I thought you needed a ton of force to bend these tubes. However, on a video of a guy showing a bent Dana axle, he said it only takes 500 lbs of force to bend a tube. That's wild. So surely the pothole did it.

I'm going to take the wheels and sway bar off this weekend and measure the tubes. See if there is any discrepancy, or if the problem lies elsewhere.

Thanks for the help.
 

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Roger that on the diff. jack up, read same thing. Understood alignment issue can arise from doing but it seems perfect. Did note on photos, if looking at garage door and if that’s on the vertical, to me both wheels have negative camber. Last time I did alignment was on our ‘66 Beetle and that was with magnetic line level. No one wanted to touch it but did go through set of cheap tires experimenting (finally got it), front only there.

I would think pothole hit would be bent rim before bent axel, tires and shocks must help immensely with bad jolts? Surprising how accurate measurements can be on level garage floor (may be pitched?) with just measuring. Equal air in tires of coarse. No idea why chart isn’t identical on each side unless part of alignment specs, tire edge wear is very quick if off. You’ve forgot more than I ever knew about alignments but they “wing ’em” up here in ME too. Any toe in or out discrepancies I always though tires are working against each other. And then the crowned road syndrome, tire rotation every 4 or 5K miles helps here anyways.
 

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Discussion Starter · #5 ·
Roger that on the diff. jack up, read same thing. Understood alignment issue can arise from doing but it seems perfect. Did note on photos, if looking at garage door and if that’s on the vertical, to me both wheels have negative camber. Last time I did alignment was on our ‘66 Beetle and that was with magnetic line level. No one wanted to touch it but did go through set of cheap tires experimenting (finally got it), front only there.

I would think pothole hit would be bent rim before bent axel, tires and shocks must help immensely with bad jolts? Surprising how accurate measurements can be on level garage floor (may be pitched?) with just measuring. Equal air in tires of coarse. No idea why chart isn’t identical on each side unless part of alignment specs, tire edge wear is very quick if off. You’ve forgot more than I ever knew about alignments but they “wing ’em” up here in ME too. Any toe in or out discrepancies I always though tires are working against each other. And then the crowned road syndrome, tire rotation every 4 or 5K miles helps here anyways.
Some great points you got there. Let me address some of them -

Garage floor is level for the most part, until the very back where it drops off to the driveway (there's a half inch slab). That area gets weird. But where it's parked in the garage in the photo, it's level.

I RELIGOUSLY check tire pressure. Like every other day. They are always set to 33 PSI cold. It's the happy medium for comfort, grip (straight line and braking), handling and nimbleness.

The garage door does look flipped in both photos, and they do look odd. Thanks for pointing that out.
It's really hard to get an exact comparison with a phone camera and shaky hands lol. However, in person you can tell by looking at each of them that the driver side is as straight as a live axle normally is, or even slightly positive, whereas the passenger side's top of tire is kind of tucked into the wheel well (negative). My angle finder will back me up on this.
I have measured parked on the garage floor, in the sloped driveway, parked both away from the garage door and toward the garage door, and in various street locations (in front of my house, work parking lot, Chick-Fil-A parking lot etc.) All readings are roughing the same: 90.0 - 90.2 degree angle driver side wheel, 89.3 - 89.6 degree angle passenger side wheel. I am measuring on the wheel center cap, as measuring on the tire or wheel spokes are not accurate enough because of tire pressure, sidewall bulge, and wheel spoke design variations.

It is worth mentioning that the axle is near perfectly centered with BMR's adjustable panhard bar as well. A difference side to side by a mere 1/16th of an inch. Which is not worth correcting.

ANOTHER thing worth mentioning is that my Whiteline rear sway bar is not perfectly centered on the axle, even though the end links are perfectly placed in their frame mounting positions. Sway bar sits slightly more towards the passenger side of the axle with very little clearance to get even a pinky finger between touching the sway bar and touching the axle.

I completely thought my wheel was bent after that impact. I thought my brand new bumper I got was toast as well and surely the airbags should've gone off. But nope. My Koni shocks are still perfectly fine and each side compresses and rebounds at the same rate. Just as stiff and uncomfortable as they were brand new lol.
I think if that impact was the cause of the axle problem and if it is truly bent, then I did get extremely lucky to get out of it with only a bent K-member and bent axle tube.
A fair note for anybody that's as ridiculously dumb as me: don't go chasing a supercell thunderstorm in your beloved sports car. Because you could hit a portion of highway that's pooled with rain, start hydroplaning and smack a pothole, potentially totaling your car. Yes, I deserve the consequences for taking my Mustang to be a wannabe storm chaser lol.

Like I said in my reply to Yadkin, I am going to jack the car up, NOT BY THE AXLE, this weekend and take all the necessary measurements to determine if any part of the axle is truly bent.
If the axle is bent, whatever. Either save for a new rear axle assembly (I mean I want to go back to 3.55s anyway), or do the heat up/ice down trick on the tubes to try and get them back center, and then replace all internal parts. If the axle is NOT bent, great! But then I need to figure out why the measurements on the wheels are off. Maybe stick a set of spares on the back and see if my wheels are messed up. Although, I have zero symptoms of a bent wheel, so I highly doubt the wheels are the problem.

Thanks Braindead for the reply. Hopefully I will come back with good news this weekend.
 

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Now, like I said, I thought you needed a ton of force to bend these tubes. However, on a video of a guy showing a bent Dana axle, he said it only takes 500 lbs of force to bend a tube. That's wild. So surely the pothole did it.
The weakest part of the assembly is where the tubes connect to the pumpkin. They are pressed in. So if bent, it's probably at either location.

I've seen professional tire guys jack from the pumpkin. It's a common mistake, even among guys who should know better.

You can safely jack the car from the rear axle. But you need to do so as close as possible under the spring seat. So you jack one side, place your stand next to the jack, then do the same on the other side.
 
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Discussion Starter · #7 ·
The weakest part of the assembly is where the tubes connect to the pumpkin. They are pressed in. So if bent, it's probably at either location.

I've seen professional tire guys jack from the pumpkin. It's a common mistake, even among guys who should know better.

You can safely jack the car from the rear axle. But you need to do so as close as possible under the spring seat. So you jack one side, place your stand next to the jack, then do the same on the other side.
Thanks. I'll make sure to do it that way from now on.
 
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