IRS Negative Camber

[Darkstar001]

This topic has come up before, but I couldn't find a satisfactory answer.

The rear passenger wheel on my Super has about 4 degrees negative camber. The rear end has a slight amount of sag, but I don't think this has anything to do with the spring plates since the driver's side wheel isn't affected as much, and I understand that IRS cars should NOT have camber in the rear. Do I have a bent trailing arm or torsion bar? Something wrong with my brake/axle assembly? I just can't figure it out. I would leave it alone except that it's wearing out the tread on the inside of the tire.
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'71 Super Beetle (Clementine)
'71 Super Beetle Convertible (Johanna)

[Derek Cobb]

Could be the pivot bushings smushed....That'd do it

[dreadnotmusic]

I have the exact same problem. I can't stand looking at the passenger side because of it. I can't see anything underneath that is bent or distorted.
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66 Riviera

[westcoast-paul]

you'd be surprised how much camber you can adjust when playing with the three (or 4) spring plate mounting bolts.

At first i thought there is no way camber could be effected / adjusted. but - with the car on the hoist, me underneath, snap-on alignment lasers pointed - it was amazing.

so - sounds like the spring plate bolts went out a little.
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- Paul

[dreadnotmusic]

[Different Drummer]

I hope westcoast-paul is correct.
After rebuilding the rear suspension on my 1972 I have noticeable Pos. camber on the driver side. I am getting ready to take it for alignment and was under the impression that camber could not be adjusted without playing with the indexing of the torsion bar. Which of course would change ride height which I presently have where I want it.
Anyone know more about this?

[Different Drummer]

Any one else know anything about this topic?
Comments?
Westcoast- paul, any more info?
I am really curious about this issue with camber in the rear on IRS suspension.

[andk5591]

You can rotate the assy on the spring arm a little. If you loosen the bolts you can twist a little one way or the other and this impacts camber.

On my project, I lowered about 2" in the rear. I actually slotted the holes a little to get it pretty close to 0 degrees. My understanding is some Porsches have the spring arms slotted for this reason, but I don't know that first hand - just read it on Samba. So yeah - this can make a different, but make sure the diagonal pivots are as they are supposed to be first.
_________________
D-Dubya Manx clone 1914. Ex wifes car.
Rosie 65 bug - My mostly stock daily driver.
Woodie 69 VW woodie (Hot VWs 7/12).
"John's car" 64 VW woodie - The first ever
Maxine 61 Cal-look bug - Ex-wifes car.
66 bug project - Real patina & Suby conversion
There's more, but not keeping them...

[Bruce]

The camber can be affected by tilting the TA relative to the spring plate. Tilt the rear of the TA up, you get positive camber. Tilt it down, negative. Slotting the holes will get you more range.
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[Different Drummer]

Bruce and andk...
My spring plates are slotted horizontally for fore and aft adjustment.
Are you both suggesting that the holes are large enough to allow vertical movement between the the Diagonal arm and spring plate? I did not look real close at it while apart as I saw the obvious horizontal elongation in my 3 hole spring plate. ( 1972 ).
Good news for me if this is the case!
My right side looks fine. Must have just lucked out when I installed that side.

[Bruce]

There is some clearance vertically in the bolt holes. Most likely you will have to slot them more. I recommend you slot the holes in the TA. That way your spring plates don't end up with giant holes in them.
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[andk5591]

There is some vertical play in the existing holes and it may give you enough. If not then - enlarge the holes on the spring plate a bit to see if you get what you need. VERY VERY IMPORTANT - make sure you you enlarge the correct direction. Aks me how I know You can do it without removing the diagonal arm. Pull the shock and jack it up as high as you can.

If slotting gives you enough, great. If not, then you may have to do the diagonal arm. I left the one hole closer to the torsion spring alone and used it as the pivot poin, but you could also enlarge it to get more twist if you need it.
_________________
D-Dubya Manx clone 1914. Ex wifes car.
Rosie 65 bug - My mostly stock daily driver.
Woodie 69 VW woodie (Hot VWs 7/12).
"John's car" 64 VW woodie - The first ever
Maxine 61 Cal-look bug - Ex-wifes car.
66 bug project - Real patina & Suby conversion
There's more, but not keeping them...

[Bruce]

[andk5591]

Bruce - I could swear that I had seen Porsche trailing arms with enlarged holes.
I am not saying hog it out an inch - just the play in what is there can make a bit of a difference. Going another .060" may be plenty to do what they need. Also - Mine are the dual spring plates. Should have mentioned that as well.
_________________
D-Dubya Manx clone 1914. Ex wifes car.
Rosie 65 bug - My mostly stock daily driver.
Woodie 69 VW woodie (Hot VWs 7/12).
"John's car" 64 VW woodie - The first ever
Maxine 61 Cal-look bug - Ex-wifes car.
66 bug project - Real patina & Suby conversion
There's more, but not keeping them...

[Bruce]

[andk5591]

Fastenall has them though......
_________________
D-Dubya Manx clone 1914. Ex wifes car.
Rosie 65 bug - My mostly stock daily driver.
Woodie 69 VW woodie (Hot VWs 7/12).
"John's car" 64 VW woodie - The first ever
Maxine 61 Cal-look bug - Ex-wifes car.
66 bug project - Real patina & Suby conversion
There's more, but not keeping them...

[Motomazzo]

[donmurray]

Spring plates allow some lateral movement, but not much vertical because it could put the angle arm bushing in a bind. Lateral adjustment would be for small corrections to rear toe in. Before removing the spring plate bolts mark the position so toe in is not changed (unless you want it to).

Some camber is present is almost all suspension systems when they move up and down, and they usually have a bit of negative in normal pose. VW IRS normaly has a little neg camber on the ground, when empty. If sagged, the torsion bars can be adjusted, but it's not an easy procedure. A spring plate tool is highly recommended. There's a lot of load on plate ledge, and the plate has to be compressed to unload it while removing the 4 torsion bar retainer bolts. There are threads on doing this adjustment.

[Bruce]

[andk5591]