Bent Rear Axle

[pepecat]

:{ Well I was in denial when I got the truck out of the 4 wheel laser alignment shop... They claimed that my right rear wheel had 4 5/8" Toe and 13. 7 deg CAMBER?!?!?!?!?!? :{ the only reason I brought it in was to get the steering wheel centered (and I had just installed a borgeson) and check the front basically for toe, which is all good BTW. I do have warped rotors for sure because I feel pulses while braking, but they've always been there just haven't put rotors on the priority list. Anyway it is to the point now that I'm trying to smooth out the ride because the vibe was driving me crazy last trip up to norcal (1000 miles or so round trip) because I thought that since the wheels were balanced there should be no vibe, but it still does have an intermitent one at speed. Now the steering is aligned and the wheels are newley balanced. Rotors next, but in the back of my mind I'm wondering if theyjust messed up. How could one side be perfect and the other be so far out? I think my 5" chrome tip right in front of the rear wheel must have put some reflections into the lazer alignment machine to throw it off... the only good thing is that the alignment was free because they had pitty on me for having a "bent rear end". I went underneath just now with a ruler and put the straightedge on the two u-bolts on both sides and the edge was just about on the same point on the center housing when checking both sides, save for a little error on this very unscientific method. Never any bad tire wear on the back two either...

what gives?

 

[paccool]

I think I would find another shop! H*ll, you could see a toe that was out that much just by looking. Same for the camber. Not to mention the tire wouldn't last long.



I've seen several "laser alignments" done on large drive shaft setups that I could see the misalignment just looking at it when they finished. If the operator doesn't know how to set it up right, a laser is useless.



Did you measure center to center from front to back on both sides?

 

[pepecat]

Good Idea!

C to C front and back of the wheels were dead on equal. You're right looks like the shop was on cr@ck, but the upside was that I got a free alignment out of it

 

[Philip]

Don't trust a C to C measurment. Go to this link and scroll down. You will find a pic I posted a long time ago. This axle measured C to C on both sides perfect. But look close at the straight edge. A laser rack told me it was bent 1 3/16". That straight edge shows the bend.



https://www.turbodieselregister.com/forums/showthread.php?t=56738&highlight=bent+rear+axle



If you don't trust the shop you were at. Go to another one. If both say the same thing then you have a problem. You won't see much tire wear on a bent axle with SRW's on it. A dually will eat a set off fast. Mine would eat a set of rear tires off in 10k miles.

 

[pepecat]

C to C

Ok, sounds good I was planning on getting a second opinion just to make sure anyway, however, I think that at least there would be some C to C difference if the shops #'s were correct. Alomst 5" toe and 13 deg out of camber should be at least noticable by C to C, if not even by eye. BTW this morning I was driving to school at around 75 the whole 20 miles and only by the end of the trip did I notice any of that vibe, it seemed to occur after the front brakes had heated up... So this is the plan, alignment, front brake job/possible balljoints/bushings & My Moog 7226S springs that have been sitting in my living room for a few weeks now.

Nick

 

[Philip]

Nick I had my truck into two good body shops for a frame check. I had tire wear problems. The truck also was a hand full on ice and snow and rain. Both shops gave the truck a good bill of health. Frame checked straight. C to C checked good and so on. A few weeks later I was in a local tire shop to have a set of 10k rear tires replaced that were on thread bars all ready. They had installed a new lazer rack. I asked if it would show a bent rear axle. They said yes. I told them to check it for me. 7 months later I installed another rear axle. It took 6 months to find it and then another month to replace all the brake system the junkyard said was good.



I hope yours isn't bent.

 

[pepecat]

Well, yours was in an accident is that right? I am 99. 9 % sure mine was not, knowing the original owner and all... I concur that I HOPE the axle isn't bent...

 

[Philip]

It had been in a wreck. But the axle had been replaced. The bend in the axle was downward and straight back at the angle of the drive shaft. So this wasn't wreck damage. Someone towed heavy with this truck before I got it. It has a massive home built 5th wheel plate under the bed. It hasn't towed 5th wheel sence that wreck eather. The bed and bed liner hasn't been cut for the 5th wheel ball.



Don't trust car fax eather. LOL

 

[fox]

To check it for squareness, it needs to be done in an X pattern.

My crews bent a Dana 70 in a p series truck. Hit something and acted dumb about it.

Truck drove sideways and kept loosening the lug nuts.

We did have it over-loaded though. It was carrying 8400 lbs.

We put a Dana 80 under it. It has been fine.

What bothered me was, none of the guys knew when it happened.

 

[BushWakr - RIP]

Ok, I got to ask... . I don't know what C to C is... anyone wanna explain it to an old guy...



pb... .

 

[hdm48]

Psst,, hey OLD guy, That's "center to center"





Now I know what yer thinkin',, I knew that, right, eh? :--)

 

[DValentine]

PB, I think they are refering to the measurement from center of the front hub, to the center of the rear axle hub, parallel to the length of the truck. The more accurate measurement, as mentioned, is in a X fashion across the length of the truck.



Dave

 

[Don in Missouri]

I just back form the aliognment shop with 1. 54 degrees of toe on one rear wheel. It is wearing tires bald in about 30,000 miles. That's no where near the bend you are describing. Those numbers are hard to believe.



I'm trying to decide whether to replace the axle or not. Does anybody straighten these things?

 

[pepecat]

I remember vaugely from another thread about this that Dana only straightens axles that have been bent less than 1/4". Yeah, my numbers are outrageous, I don't ever wear tires wierd on that wheel, but time will tell, if yours took 30,000 miles.

 

[Philip]

When I found my axle was bent. I called these people.



http://www.moserengineering.com/



I asked them about replacing the tubes. I was told they do not do that. But they gave me the name of a heavy truck axle repair shop in MI. somewhere.



I was told by that shop that a Dana 70 with over a 1/4" of bend in it warps the center section also. They would not replace the tubes on an axle that had both tubes bent. Only on a collision damage rear.



As far a straightening them they said no to that also. I was told if they tried to straighten it. Most likely it would crack the center section. Or leave you a S shaped axle tube.



I forget the name of that shop. But if you call the company in the link I posted. They can give you some good leads to call.

 

[TKingsbury]

I can't believe you have that much toe and caster on a rear wheel. That thing would be so crooked you'd have to be blind to miss it. I'd get a second opinion. I assume the center to center you're measuring is the rear tires, just like you check toe on the front? Just clarifying.

Travis. .

 

[pepecat]

no doubt! I even took it into a 4X4 axle shop and he said that you'd be able to SEE it as well...

 

[fox]

Axle straigtening is done one of two ways.

One is with a press.

The other is with heat. Heat it up on the short side of the bend and it will expand and when it cools it doesn't shrink as far as it was where it started.

The press idea has been argued, with some saying not to the press, they use a big hammer/press.

If you can , I'd say replace it.