SC with Bilstein front shock replacement.

[Bill Douglas]

Hi Guys.

My SC has green Bilstein front shocks. My car is a 911SC Sport from the UK that came out of the factory with Bilstein shocks, 16" Fuchs, sport seats etc.

I've found the one on the right hand side has a small clunk when the car is on a hoist (so strut is full extended) when pushed in the middle. So a left to right clunk. The shocks don't do any bouncing and I wouldn't have known there was a problem if it didn't show up on the Warrant Of Fitness (same as the British MOT) check.

I've looked on our host's parts catalogue for replacement strut inserts but they seem to be for Boge shocks or performance orientated.

Has anyone replaced Bilstein shocks inserts, or is there another fix I can do to stop the left to right clunk?

Thanks!

[TxGerman]

I am in the middle of an entire suspension refresh on my '82 SC. I have green Bilstein struts and purchased the replacement inserts here from our host. I can't speak to your "clunk", but if it's not in your steering rack/tie-rods, seems like you might want to look at your strut ball joint.

[Bill Douglas]

Thanks TX. The mechanic doing the inspection showed it to me. He was checking the wheel bearing with the car on the hoist and found an odd clunk. On closer inspection we could see the top half of the strut had a wobble where it met the bottom half of the strut. Wobbled about 2 or 3mm.

Edit: Which inserts did you buy?

[SittingBull]

I’m refreshing my front suspension now as well. Here are the inserts I bought:

https://www.pelicanparts.com/More_Info/34050019M512.htm?pn=34-050019-M512&bt=Y&fs=0&SVSVSI=804

[Bill Douglas]

Thanks SittingBull, much appreciated. I changed the year to my car and it had the same part numbers, so great, this looks like the part. It says "Performance", hopefully that doesn't mean a track car like feel about it.

[Driven97]

Left to right clunk probably means your linear bearing is worn out. A new strut insert won't fix this if that's the case. I'm on mobile and can't search well, but it comes up from time to time on this forum so you should be able to find a hit with a decent search.

[Bill Douglas]

Thanks Matt. That's what my problem is, a bushing inside the strut to keep everything centered inside the strut housing.. It's well described here 911 Carrera (1984) front wheel bearing problem

[TxGerman]

I installed the same strut insert as SittingBull. Although my internal strut bushing/bearing is not worn out, I did look into replacing it along with my dust seal. The dust seal was easy to find, I believe I sourced it through Summit Racing. The internal bearing however is a different challenge. I could only find information about replacing it through Bilstein. When I called them about getting the parts, they informed me that I would have to ship my struts to them but that due to COVID-19 they are shut down and can't do it. They recommended that I contact a performance suspension shop in Ca but it looked like it was going to be quite expensive. So, since mine aren't worn out, I abandoned that effort and just plan to replace the dust seal and install the new strut inserts. If you need more info on this, go to this thread: https://forums.pelicanparts.com/porsche-911-technical-forum/1085541-911sc-strut-question.html

EDIT: I found my email from Bilstein, this was what they told me last month:

Thank you for contacting Bilstein of America. Due to the limited number of in-office staff in the Bilstein Tech Center, we have enlisted the service support of one of our Bilstein Distributors and have suspended, for the time being, our service center.

Performance Shock, Inc. is a Certified Bilstein Distributor and Service Center. They are located in the Motorsports Industrial Park at Sonoma Raceway, (Sears Point) in Sonoma, California. They specialize in the servicing of Performance and Racing Shock Absorbers, Springs, Sway Bars & Goodridge Hoses & Fittings.

For questions about servicing your shocks, please contact them through the information below. Thank you.

https://performanceshock.com/


Hope this helps.
Dennis

[Flojo]

I'm confused… my SC too has the green Bilstein from factory.
This design is a upside-down shock cartrídge inside the strut itself.
I cannot recall there being any kind of bushing for centering/aligning (there is a rubber bump stop though).
inside the strut there are some grease grooves that absolutely MUST be filled with special grease prior sliding the shock inside.

at bottom it is secured with a roll pin.
at to you just screw down the centering cap and done.

(anybody welcome to correct me if my memory is wrong)

[TxGerman]

Originally Posted by Flojo

I'm confused… my SC too has the green Bilstein from factory.
This design is a upside-down shock cartrídge inside the strut itself.
I cannot recall there being any kind of bushing for centering/aligning (there is a rubber bump stop though).
inside the strut there are some grease grooves that absolutely MUST be filled with special grease prior sliding the shock inside.

at bottom it is secured with a roll pin.
at to you just screw down the centering cap and done.

(anybody welcome to correct me if my memory is wrong)

From other PP'ers when I was asking about these things:

The bearing is a teflon coated cylinder that fits in the tube. This is the surface that the strut body slides on. When they wear, the strut can wobble slightly in the housing.
See a video of side to side motion: https://www.youtube.com/watch?v=sRNg_WKvxEw

I can take a picture later if needed, mine are still disassembled.

[Driven97]

Yeah it's been a while since I did it, but the process was basically:

1. knock off dust cap
2. Use slide hammer to yank old DU bushing
3. Wreck two new ones attempting to install them
4. Use harsh language
5. Succeed on installing the third one without wrecking it
6. Regrease / re-install dust cap.

For me it was looseness found by an autocross tech inspection, seemed like a loose wheel bearing. Upon closer inspection, you could see the strut body (the silver outer tube) move relative to the strut housing. The new bushing solved it.