911 SC rear spring plate bushing problem

[pmar911]

Dear forum,

I ask for your advice re. a rear suspension refresh of my 79 SC.

I have replaced the innter and outer bushings on the original spring plates and torsion bar covers (the 4 bolt hole thing) are brand new.

The everything is bolted up, it appears as there is very little clearance (9 mm) between the inner part of the spring plate and the body.

Also, there is an 8 - 9 mm gap between the covers and the outer part of the spring plate, where the outer bushing is visible.

The outer bushing is *fully* squeezed into the new torsion bar cover.

It is almost as if the outer bushing is too large and therefore pressed the entire spring plate assembly inwards, also to an extend where the torsion bar end prevents the little dust cover to fit (see pic #1).

The pictures attached are with unloaded suspension and banana arm *not* connected.

Any suggestions or is this normal when nothing is loading / connected to spring plate?

Thanks in advance.
/Peter

[Classic 911]

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[Dpmulvan]

What happened to the inner bushing?? Looks mangled. What bushings did you use?? I had some issues with fitment of uro heavy duty bushings.

[pmar911]

I see what you mean. Apologies for the bad picture. Inner bushing is fine, I think.

There is some silicone lube on the outside and the light on the picture is reflecting (or maybe a bit of overspray of gray paint from a quick patch I did).

The inner bushing has an even 10 mm lip between the body and inner spring plate.

I did avoid the low cost bushing, so the bushing is not URO, but a sport hardness type from a german reseller.

/Peter

[Dpmulvan]

Sport hardness type from a German reseller?? It doesn’t look right to me somethings off, your torsion bar is not all the way seated or something. Shouldn’t be that difficult to fit bushings in cover either.

[Uwon]

You sure you got the right size spacer on the bottom bolt? The kits sometimes provide different sizes.

Johan

[pmar911]

Hi Johan.

Thanks for your reply.

Good point. I use the spacer that was already on the car.
The distance from body to cover plate is approx 22 mm.

Is it possible to measure how much gap you have between cover plate and outer part of spring plate? ("B" on the picture below)

It looks like I have a lot of "rubber" there, and I am thinking that the outer bushing may be a couple of mm too large, so it pushes the entire spring plate assembly in towards the body.

Also, measure the body to spring plate clearance? ("A" on the picture below)

The torsion bars were not removed from the car, and I am certain they are pushed in as far as they will go.

/Peter

[jpnovak]

This is normal. What is your concern? you don't want the spring plate to push all the way to either side or you will have metal to metal contact. the bushings are flared where they meet the spring plate to prevent them from hitting either the body or the outer spring plate retainer.

[pmar911]

Thanks for your reply.

My concern is that the spring arm assembly appears to be pushed too far in now.
The torsion bar prevents the tiny end cover to seat which is unnormal, so I'm expecting that something is off, and my suspect is distance "B" above being too large.

The new bushings I've mounted are not flared.
It is "only" their size that prevents the spring plate to touch either body or cover / retainer. Which I think is ok, provided that the sizes are correct.
And again, I think the outer bushing which gives my distance "B" above is too large or can't be compressed enough.

Hope that makes sense :-)

[Uwon]

I agree with Jamie. Distances “A” and “B” look fine. You need some space there as the arm pivots inwards a bit at the end of the top and bottom of suspension travel.
Johan

[pmar911]

Hi all,

Thanks for your comments. Good that hear that distances are good.
I still can't explain why my torsion bar is sticking out now, so the spring plate must have shifted 3 - 4 mm inwards.

The new torsion bar cover appear to be slightly "less deep" than the original one which can explain some of it.

I'll take it apart and try with the original cover and see if I can get the dust cap fitted.
Again, thanks for your comments

[917_Langheck]

Just for comparison, this is what a used, oem spring plate rubber bushing set looks like.