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Lotus Europa Forums => Garage => Topic started by: Grumblebuns on Tuesday,May 13, 2014, 01:46:52 PM

Title: Rear Spax shock installation warning
Post by: Grumblebuns on Tuesday,May 13, 2014, 01:46:52 PM
I just wrapped up all work on the rear suspension of my TCS; new adjustable lower links, fabricated spacers for the Spax shocks, shimmed the output axles and torqued everything down. My main issue was figuring out why the lower shock mount was walking off the lower bushing and collapsing the rear suspension.

When I bought the TCS last Sept, the left rear shock had already come off the lower bushing and was resting on the lower bolt. The right hand shock was about half way off its lower bushing. It's a good thing that the PO parked the car when he did otherwise he would've been dragging his butt on the ground.

I'm thinking that the Spax that the PO fitted has a much narrower lower sleeve than the OEM shock. Without a spacer to make up the difference in width, the shock body is forced several degrees away from vertical when the bolt is tightened down. Suspension forces with the car moving caused the lower shock mount over time to slowly walk off the bushing. That's what I came up with anyway. Time and mileage will tell after I get this car on the road.

 

   
Title: Re: Rear Spax shock installation warning
Post by: buzzer on Tuesday,May 13, 2014, 01:58:56 PM
I have spax on my Westfield and have much larger washers on either side of the rubber mount, don't know if that helps, but I have not had any issues with them moving. Will try and tack a pic of the installation.
Dave
Title: Re: Rear Spax shock installation warning
Post by: cal44 on Tuesday,May 13, 2014, 03:08:07 PM
Thanks Joji..............I'm going to check mine.  The angle issue would seem to be of interest.
Thanks for the heads up.
mike
Title: Re: Rear Spax shock installation warning
Post by: BDA on Tuesday,May 13, 2014, 03:53:36 PM
This is a situation that can occur on the front suspension, too. Alignment is obviously important but keeping an eye out for it is a must!
Title: Re: Rear Spax shock installation warning
Post by: jbcollier on Tuesday,May 13, 2014, 05:22:30 PM
Large washers are a good idea.

I hope your spacer is not made of plastic pipe!!
Title: Re: Rear Spax shock installation warning
Post by: Grumblebuns on Wednesday,May 14, 2014, 06:46:35 AM
Large washers are a good idea.

I hope your spacer is not made of plastic pipe!!

The gray spacer does look like PVC conduit but I'm using 1" diameter hardened 2024 aluminum tubing left unpainted.

I believe the major factor for the lower shock mount slipping off the rubber bushing is that the bush is not bonded to the lower mount. Using a vice and two large sockets, I could easily move the rubber bush around in the shock mount for adjustment.

Large washers will help prevent the shock mount from slipping completely off the long retaining bolt. Unless there is a way to permanently attach the rubber to the metal mount, it's going to move around. The only thing I can do is to keep an eye on the shock once I have the car on the road. I already have an idea for a permanent fix that involves machining a cup or keeper with the same diameter as the lower mount that will fit over the rubber section and act as a washer.

Joji Tokumoto
Fallbrook, Ca 
Title: Re: Rear Spax shock installation warning
Post by: Grumblebuns on Wednesday,May 14, 2014, 07:19:28 AM
This is a situation that can occur on the front suspension, too. Alignment is obviously important but keeping an eye out for it is a must!

This is definitely true. When I replaced the metalastic bushings on the front control arms for my S2, I noticed that on the inboard end, rubber section of the bushing had torn away from both the inner and outer sleeve and forced the inner sleeve away from the outer section. I have a picture of the old bushing somewhere.
Title: Re: Rear Spax shock installation warning
Post by: JLM on Wednesday,May 14, 2014, 11:45:35 AM
Joji -Thanks for posting this. I too have Spax on all four corners, however my TCS is still on jack stands. I have some steel sleeves I bought just for this issue, haven't got around to cutting and fitting them between the shock and rear upright. When I first fitted the Spax to the rear I saw the space where the original shocks used to be and figured I'd need to put something there to avoid slipping. Now I need to check the fronts as well.

Title: Re: Rear Spax shock installation warning
Post by: Grumblebuns on Thursday,May 15, 2014, 06:43:29 AM

Larry,
The PO failed to use spacers and it only took around 160 miles for the shock to work its way off the lower mount. Before I drive my car, I hope to have a better retaining method than a large washer fabricated.

Joji Tokumoto
Fallbrook, Ca