Well now I know why my spring plates made so much noise

EarlyPorsche · 08-02-2010, 11:52 AM

I know my Porsche. Its real straight and strong but it had a rear spring plate bushing noise. I had set the torsion bars when I first purchased the Porsche but I didn't know a bunch about them then.

So I took the driver side spring plate off and noticed there are not only POLY bushings in there but they are Weltmeister 356. They say 356 on them. The previous owner had the vehicle repaired at shop that only did 356, 912, and 65-73.5 911 restoration work. Could it be that they put 356 rear bushing on my 66 or is that the correct part. As far as I can tell that is not the correct part. Luckily I have rubber bushings on the way.

356RS · 356RS's Garage

The 356 and early 911, 65 - 68 used the same bushing size. Only the torsion bar cover plate was different on the 356. Example: In the Elephant Racing catalog the rear spring plate bushing kit for the 356 states you can order the early 911 kit if you change to the 911 spring plate cover.

EarlyPorsche · 08-02-2010, 06:06 PM

Oh ok! Then the only problem I actually had was that polyurethane bushings are obnoxious! I think they should stay on track only vehicles. The fit on them isn't even that poor but in reverse and over certain bumps they make a distinctive thud.

Cornpanzer · 08-03-2010, 04:22 AM

The biggest problem with poly bushings is usually installation. They cannot be installed directly out of the package because they are too large and wont compress like rubber. You have to carefully fit them to the torsion housing. If you try to force them in and then draw the cover down on them, they close down over the inner torsion tube and prevent it from twisting like normal...which causes noise and stiffness.

EarlyPorsche · 08-03-2010, 07:48 AM

So the inside of my spring plate bushing covers are a pitted because the poly didn't fit tight and allowed water in under the outer bushing. Would you guys say I should spray the inside of the plate with something to build it up like rubberizer or just leave it as it is?

Fritter · 08-03-2010, 10:44 AM

Leave as is. I did the Grady Clay Method and drilled two holes in the bottom of the torsion tube for drainage/breathing. Cleaned the inside out good and coated with Wurth anti rust wax. I greased the bars up good. I also greased up my new rubber bushings with silicone grease.

304065 · 08-03-2010, 11:08 AM

Quote:

Originally Posted by 356RS

The 356 and early 911, 65 - 68 used the same bushing size. Only the torsion bar cover plate was different on the 356. Example: In the Elephant Racing catalog the rear spring plate bushing kit for the 356 states you can order the early 911 kit if you change to the 911 spring plate cover.

Actually, the bushing change was from Chassis 307325, in 1967.

SWB spring plate bushings