Spring Plates

[Gumby]

Advice needed...I have a thunk coming from the rear suspension for some time, only when cornering, otherwise no noise.
I have had my shop check it out, he checked everything and dismantled, re lubed everything.

( all new bushings, shocks even new drive shafts/cv joints replaced a few years ago )

Now he is thinking the spring plates are worn, he checked and there is some "play"
is this correct? can there be any play?
All advice is welcomed.
Thanks, Ron

[buddeman]

Hi Ron,
Had two similar issues on a SWB and 356A - both related to non-standard rims... for what it's worth:

On my '67 SWB, I added adjustable spring plates, which when combined with deep 6 fuchs created a rubbing situation where the rear tire would actually rub against the spring plate adjustment height bolts/nuts... but only during aggressive cornering. Straight line driving or gentle corners kept the spacing. Adding a spacer quickly resolved the problem.

Similar on my 356A, I also had non-standard wheels (5.5") where one rear rim would rub against the lower shock bolt... but again only during aggressive cornering. This was more of a thunk-thunk-thunk sound... And once again, a spacer came to my rescue.

[greens]

Hey Ron: My experience was this was the rear sway bar bushings on the trailing arms being worn. Also, if the mounts were bent somehow, that could cause a misalignment. Lastly, make sure the stub axle bolts are tight if they have been off recently. Same goes for engine and tranny mounts, need to be real tight. As far as the spring plates, if you look at the rear torsion bars where they come our of the mounting plate, it should generally be centered in the plate. When they wear, the torsion bar will be forced to rest on the upper part of the spring bar plate by the weight of the car. But a lot of cars have this and unless it is really worn I can't see it making a thunk.

[Gumby]

Jim, all bushings were replaced but.....you bring up bent sway bar mounts which I do indeed have, can I simply just bend them back or will this require a large amount of heat?

[greens]

No I just used a little tap tap tap with a small hammer and channel locks and went slowly. Just make sure the welds to the chassis are still solid when you are done. To confirm this might be it, look for interference point between the bar and the front eng/tranny mount or other metal to metal along the length of the bar. Doesn't take much to create a bump.

And then let's hook up for a drive before the end of the nice weather!

[Gumby]

Jim, I think you may be on the correct path, The bar does indeed interfere with the tyranny mount! (or is it the other way around?)
when all have failed to solve the "thunk" they were looking in the wrong direction...

I'll take a look under her "skirt"...TBC

[blucille]

I have some spare, not adjustable, spring plates, let me know if you need one,a pair, or a couple of pairs, either way, happy to help.

[Gumby]

Thanks Lewis..stay tuned!

[Silverbullit]

Perhaps disconnect sway bar, secure it, and drive it and compare.

[Gumby]

Thanks, That will be my next step