Question about rear stock sway bar bushings on an SC

[universeman]

I just replaced the rear sway bar bushings in my 82SC today; the old ones looked squashed and deformed (and were hardened with age.)

I put the new ones in and they look...well...slightly less squashed and deformed.

The slot in the rubber does not close around the bar. It's open like 10 degrees or so, against the frame of the car, because it looks as though the bar is bigger than the bushing can handle.

Is this normal? I can post a pic if it helps.

[Ayles]

Please post! I had a hell of a time with mine. Finally had to pick up bolts that were 5mm longer than stock just to get it together. I have the gap in my bushings too.

I looked at tons of pics and I think it's somewhat normal.

[zippy_gg]

Did you check the size of your sway bar before ordering the bushings?
Is it possible that a PO upgraded to a larger diameter so your bars are no longer stock?
Just thinking aloud here...

[universeman]

Ayles the job was a lot easier once I put the car back on the ground. Until I did that, I couldn't get the bracket back together with those shorty bolts either.

Zippy, the sway bar and hardware all seem original to the car. No way to know of course, but everything else is stock so I just don't think the car has been upgraded with a larger bar.

This picture shows the bushings I took off the car. You can see the amount of deformation/spread in the one on the right. The one one the left shows the surface that was squeezed against the car, apparently the bracket is not smooth and shaped like the top of the bushing:



The picture of the new bushing on the car shows the gap I'm talking about. Everything is back in place and torqued to spec (18ft-lbs.) Another curiosity is that the PO put a piece of rubber hose around the center section of the sway bar (can be seen in the pic), probably to keep it from clattering when it flexed and hit the transmission crossmember, which I think I heard it do. I'm wondering if that's because of old bushings. The new ones seem to hold the bar further from the underbody by a bit, but not by more than 2-3mm.



Any thoughts?

[boyt911sc]

Jason,

The gap at the top of the installed bushing look too much but that's the way they come. I got four (4) cars ('77S, '78, '87, & '89) and they all exhibit similar gaps. It would be nice to find a properly sized rubber bushings that fit well. So far I have no problem with these bushings. BTW, what size (mm) is the rear sway bar?

Tony

[universeman]

Thanks Tony,

I have seen a few other pictures and it seems to back up what you're saying.

This is a stock sway bar AFAIK, so 18mm. I guess I could measure it...

[Vereeken]

If your gap would be completely closed where would the energy of the roll bar go?
Straight into the surrounding rubber and thus always rubbing the bushing in a fight for space. Now the energy can go in the deflection of the bushing thus closing the gap.

This is my theory. perhaps the dudes from Elephant racing should reply or an F1 engineer.

It is a good question and I have seen it on other cars as well.

[universeman]

Oddly, the front sway bar bushings close completely. But I can't imagine a Porsche engineer inspected that on the prototype SC, and let it go unless it was as-designed.

[gtc]

The photo looks fairly normal, but you could still go measure the rear bar diameter for the heck of it. Someone may have installed a later 21mm bar ('86-'89) at some point. If you don't have calipers handy, the size should be stamped on one of the ends near the droplink.

[tirwin]

I just went through the same thing recently. Here's a pic. Stock sway bar (18mm). I don't recall who made the new bushings. The old ones did not have the same gap.

[Solamar]

Bumping this old thread to see if there have been any improvements in the fit. Squeezing the 18mm sway bar into a 14mm bushing with the gap spread open between the bar and frame just seems completely wrong.

I thought a correctly setup sway bar should move smoothly through it's range of motion, not add to the spring rate...

Anyone try the Carrera 20mm bushings on a 18mm SC sway bar?

PN 477-411-313-C-M260

[UROParts]

What's the ID of those bushings?

Here are the specs for our rear Sway Bar Bushings, which have the same durometer as OEM.

• 477 411 313B for 18mm bar (15.70mm ID)
• 477 411 313C for 20mm bar (18.08mm ID)
• 477 411 313D for 21mm bar (18.65mm ID)
• 477 411 313E for 22mm bar (19.90mm ID)

[manbridge 74]

It appears the later type bushing is being used incorrectly in pics above. They are designed to fit in a recess in the body. The bushing that is flat on top is designed to fit a flat surface as seen on some year 911s.

[Solamar]

Originally Posted by UROParts

What's the ID of those bushings?

Here are the specs for our rear Sway Bar Bushings, which have the same durometer as OEM.

• 477 411 313B for 18mm bar (15.70mm ID)
• 477 411 313C for 20mm bar (18.08mm ID)
• 477 411 313D for 21mm bar (18.65mm ID)
• 477 411 313E for 22mm bar (19.90mm ID)

Thanks for your reply. I have zero bushings at the moment, so can't help you with the ID. Last night I searched all relevant Pelican topics about the SB bushing and one of the threads mentioned the 18mm bar bushing was 14mm ID (IIRC).

I'm not a suspension setup expert, but am I correct that you do not want the sway bar binding at the bushings? The 20mm bushing looks like a reasonable compromise to me

[Solamar]

I just received my bushing order from Pelican. For my 1978 SC 18mm rear sway bar I ordered -

477-411-313-C Which is for a '85 Turbo 20mm rear sway bar. I ordered the OEM brand which is labeled with the Porsche triangle logo and has the Porsche p/n on it

Bench fit -


And installed -







In my opinion, this is a perfect factory fit. When tightened in the mount, the swaybar is not at all loose to rotate, but can be rotated by hand with moderate resistance. The bushing completely surrounds the bar, but is not being overly deformed.

Makes me wonder if there has been a P/N error somewhere along the line?

[manbridge 74]

Yes, good pictures. Proper fit for mount type.

The issue is the later updated reinforced mount has been installed on many pre-85(?) 911s requiring a newer style bushing. My 74 is like this.