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Bending rear axle for rear camber...

4K views 14 replies 8 participants last post by  crwchf01 
#1 ·
Has anyone thought about bending the rear axel to get camber on the rear wheels?

'Fubes' from UK Saabs was thinking about doing it to his track car. He suggested he might be bracing the floor and putting in a trolley jack to press the axle down in the middle. I reckon a more sure-fire way of getting it right would be to take off the rear axle and get the guys at the exhaust shop to put it on the pipe bender!

So how much of a bend would you need and how much rear camber would you be aiming for? 1 degree?

Would also need to add in some wheel spacers as the inner edges of the tyres sometimes rub with the original setup and this would obviously increase if the camber was adjusted.
 
#2 ·
to get about 1 degree of camber at the wheels you would probally need to bend the center about .25*.You could heat the axle tube then gently set the wieght of the car on it.Then just hold it at that level of desired camber until tube as cooled enough to support weight again.this would require an oxyactalene torch and a fork lift.
 
#3 ·
Gearhead said:
this would require an oxyactalene torch and a fork lift.
oh yea, was just about to throw those out but now that you mention it... I should probably keep them as they'd be useful for this sort of thing! :roll:

Actually, you can eaisly lift the rear of the car high enough to walk under if you clip the engine hoist to the boot catch and raise the hoist!
 
#4 · (Edited)
You'll need to get the length of the axle from centre of each wheel (then half it), then use a bit of trig to figure out how much of an angle you need to put on it, and double again to get the overall bend angle.

It's been too long since i did any to remember without notes which side of the triangle you apply cos/sin/tan to to get the length of the other sides.


If you've got a thingy handy to measure angles draw a triangle with one 90 deg corner, with the horizontal line 10cm long, does'nt matter what length the vert. line should be but make it 5cm, then draw the last line to make the triangle, now from the far end of the horizontal line measure 10cm up the angled line, draw a line from there back to the where the horiz/vert line meet, if the angle between the vert. line and the one you just drew is the same as the angle between the horiz. line and the angled one, you can definitely work it out!
 
#6 ·
I've read recently in a magazine that racing teams have bent the rear axle in the past.

What I said about wheels rubbing in my earlier post isn't right though.

The wheels would rub less if the top of the wheel would be tucked further inboard so would be less likely to catch the wheel arch on the outside edge like you get with 9000 wheels and standard camber.

Depends on which wheels you're using though. If they were normal 900 wheels I doubt you'd see any major issue.

I believe adjustment of the camber on the rear wheels would be a worthwhile mod.

There is nothing built into the rear suspension setup to allow the camber to change as you drive so the rear tyres could be riding on the outside edges when cornering hard.

A bit of camber adjustment could see you ending up with more tyre on the road during hard cornering.
 
#15 ·
Appreciate the math and all, but has anyone considered a shop that does driveline and propeller shaft work? They probably have a jig set up for shaft straightening (think bigger boats folks) and probably have tools to measure as you deform. Also remember that you will have to over shoot the deflection you want so the axle will spring back to the final measurement.
 
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