This summer me and my uncle installed all new shocks and springs (OEM) on the rear...We had to drop the rear axle so we could get the new springs in...Now my tires are bald on the outside edges...My dad said it could be from the rear end out of adjustment...But i dont remember there being an adjustment....Any help please
Rear End Alignment?
- Thread starter Peg8687
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TrickFlow
Member
if your frame were bent or the toe was off, you could get crab walking (dog walking, as you put it). doesnt sound like your problem. im rusty on alignment stuff, but sounds like your camber is off. check that everything is installed correctly. problems can be magnified with incorrect tire pressure. you may be able to do some research and figure out a way to shim the rear end to achieve correct geometry. i dont know if adjustable arms would allow correcting of this. im not well versed on the adj rear end stuff. im sure someone knows.Peg8687 said:
good luck
donsbad68 said:There is no adjustment as previously stated unless you have adjustable race arms. Just stop spinning your tires so much and that baldness will go away.
this is true, but it will only adjust the pinion angle, right?
which isn't going to change how the tire sits on the ground........
since no one has any ideas, they just fill up the board with stupid stuff. for the slower people, let me elaborate.
yes the rear end is non adjustable. so how did it get out of whack. it was in an accident, run over curbs, frame twisted, etc. since there is no adjustment, how else would it be out of alignment (not from mis-adjustment). this is all assuming the rear end really is out of spec, which i have no way of knowing.
so when something traumatic enough happens (ie. being rear ended), what do you think happens to the unibody and things attached to it? the force is absorbed by these components and they tend to bend and get out of spec. so a frame shop puts the car on a jig and straightens everything as much as possible. but it seldom goes back to original. so SHIMS are inserted in the frame and supporting structure to achieve the original geometry again.
what do you think a body shop does when your unibody tin-can gets hit and has to be put back together?
yes the rear end is non adjustable. so how did it get out of whack. it was in an accident, run over curbs, frame twisted, etc. since there is no adjustment, how else would it be out of alignment (not from mis-adjustment). this is all assuming the rear end really is out of spec, which i have no way of knowing.
so when something traumatic enough happens (ie. being rear ended), what do you think happens to the unibody and things attached to it? the force is absorbed by these components and they tend to bend and get out of spec. so a frame shop puts the car on a jig and straightens everything as much as possible. but it seldom goes back to original. so SHIMS are inserted in the frame and supporting structure to achieve the original geometry again.
what do you think a body shop does when your unibody tin-can gets hit and has to be put back together?
I dont believe the rear end (solid axle) can be out of allignment in a way that would burn the outer edge of the tires. Even if the frame was out of square and it was dog/crab walking the tires are still both pointing in the same direction. It would just make the rear come around slightly and appear to be going sideways down the road. You would have to have an independent rear with seperate toe adjustments for each wheel in order for there to be mis alignment of the order that would cause the aforementioned tire wear. If it was "pulling" the rear down the road, I would think you would see the outside of one rear tire and the inside of the other rear tire going bald. You may need to check your tire pressure first and go from there. But, then again, I could be wrong.
the axle housing itself can be bent enough to manifest strange tire wear. this will cause camber issues. it doesnt take much to show wierd wear, yet look ok to the naked eye. also, the rear end will still work just fine in this condition.
also, the flanges and axle housing can become bent from doing power slides, 4 wheel drifts and stuff like that. this can happen when the car is slid and the coefficient of friction increases dramatically and immediately (as when traction is regained) while the car is sliding laterally. people do this all the time and not realize they did any damage.
also, the flanges and axle housing can become bent from doing power slides, 4 wheel drifts and stuff like that. this can happen when the car is slid and the coefficient of friction increases dramatically and immediately (as when traction is regained) while the car is sliding laterally. people do this all the time and not realize they did any damage.
MustangPunk302
Founding Member
HISSIN50 said:
A good body shop will straighten it right out... We never let a car with a bent frame leave our shop..
Wait. If you bend the axle flange the way you have stated then the wheel would wobble noticeably when it spins. You would also feel the shaking of the wheel at higher speeds/rpm's. The only way I can imagine you could get a noticable change in toe on a solid axle rear would be if either or both axle tubes were bent horizontally forward or rearward. I think to get even wear on the outside of the tires you would need forward bending so that toe was increased.
you're right. i meant the entire assembly (as in the whole tube). i have seen cars that were symmetrically bent (each tube hung downward from the diff., creating symptoms similar to what this guy describes). seemed to result from rear-enders. the housing can be bent with the axles still working ok (straight) due to the dynamic fitting of the internals.guerro said:
yes, you are correct. if the axles themselves were bent, it would wobble and become undrivable.
as Mustangpunk302 stated, a shop can check it. without seeing the car in person with proper resources to check the trueness, it is all conjecture and not worth debating. the point was to throw out ideas of general things to look at. i have kept it going due to people jumping me because they didnt understand what i meant, or maybe im just not articulate enough to convey my thoughts and wanted to try to clarify.
cool and thanks, guerro. my comment wasnt directed at you. your comments were valid and when i re-read what i typed, it was ambiguous. a pet peeve of mine is mindless criticism/ S.A. comments w/o any info behind it or correct detail added. you did not do this. the point is to try to help the poster. so when people make comments without correcting me or adding useful info, i find that to be a waste.guerro said:
again, your points were poignant.
i was sorta' distracted and should have read my response more carefully. this led my incorrect verbage. i had said axle flange when meaning housing [flanges] (to mean the ends of the diff housing). nothing to do with the actual axles or internals.
so, just to reiterate, the diff housing might need to be checked for trueness. not the axles or internals, but the housing. if it is bent, it may be trued and thus correct the geometry. i hope this makes sense and is along the lines of what you were thinking, guerro. thank you for pointing out my error and WHAT didnt make sense with elaboration. im only here to try and help. anyone can check my past posts and see that i often say that i dont know half as much as others and am throwing out things i would do or that make sense to me, but im certainly no expert or sure of the solution. i appreciate your helping me to accomplish this.
i usually say (but didnt this time): this is my two cents worth from my two cent brain. hopefully someone else has better info.
good luck
Michael Yount
Mustang Master
Just to be sure we're not all guessing wrong - Peg - what the heck kind of car are you talking about? Maybe I missed it.
If it's a straight axle rear end, there is technically no adjustability designed into the components. However there are special tools available to help adjust in the event that some sort of collision or abuse has caused the rear end to become 'misaligned' or 'bent' in the manner described so eloquently by my good buddy Hissin.
Ford special rear end tool part number BFSH#2995 (BIG F#$@%ING SLEDGE HAMMER - $29.95) can be used to cause certain percussion adjustments which, if applied repeatedly by the skilled hands of a large and powerful mechanic (often named Bubba) will eventually encourage things back into their proper pre-collision or pre-drifted-into-a-big-arse-curb position.
On a more serious note, I don't know of any solid axle rear ends that have adjustability built in. It takes body shop chassis straighteners or a good alignment mechanic bending things to get one back into shape if it's out of shape. Of course rear IRS is a different animal - but while your initial post wasn't specific, it didn't seem like you were talking about a late model Cobra. Bushings, shocks, improper inflation and separated belts in the tires can cause weird wear patterns as well. Unless you know the car's been hit or run into a curb or something (anything you'd like to tell us that you can't tell your dad?
), I'd rotate the tires (if front and rear are the same size) and check for the wear continuing before I got too concerned about it.
If it's a straight axle rear end, there is technically no adjustability designed into the components. However there are special tools available to help adjust in the event that some sort of collision or abuse has caused the rear end to become 'misaligned' or 'bent' in the manner described so eloquently by my good buddy Hissin.
Ford special rear end tool part number BFSH#2995 (BIG F#$@%ING SLEDGE HAMMER - $29.95) can be used to cause certain percussion adjustments which, if applied repeatedly by the skilled hands of a large and powerful mechanic (often named Bubba) will eventually encourage things back into their proper pre-collision or pre-drifted-into-a-big-arse-curb position.
On a more serious note, I don't know of any solid axle rear ends that have adjustability built in. It takes body shop chassis straighteners or a good alignment mechanic bending things to get one back into shape if it's out of shape. Of course rear IRS is a different animal - but while your initial post wasn't specific, it didn't seem like you were talking about a late model Cobra. Bushings, shocks, improper inflation and separated belts in the tires can cause weird wear patterns as well. Unless you know the car's been hit or run into a curb or something (anything you'd like to tell us that you can't tell your dad?
), I'd rotate the tires (if front and rear are the same size) and check for the wear continuing before I got too concerned about it.Similar threads
