CSR damper / rear suspension refurb + found broken damper clevis

[vertew]

I'm currently getting on with a 'lockdown' refurb on the rear suspension of my CSR + getting the Bilstein shocks rebuilt at the same time.  I wanted to take a closer look at the rear suspension, which hadn't been disassembled during my ownership - the wishbones have some road rash and I wasn't sure on the condition of the rod ends / spherical bearings etc.

When I removed the n/s damper lower mounting bolt, I noticed that part of the 'damper clevis' (which mounts lower shock to hub and also holds the camber shims) was damaged - one side had a piece missing, meaning that the entire shock assembly was only attached to the car on one side of the clevis … wasn't part of the plan, but glad I found it.  Ref pic [1] below.

So, the boredom refurb had suddenly become a bit more serious.  If left, the clevis could have failed, causing the shock to detach and the wheel to collapse up into the wheel arch.  Some research revealed two things pretty quickly: 1) the broken 'damper clevis' part only appeared to be available from CC as part of a complete assembly and costs £1,300 … per side and 2) blatchat continues to be an incredible resource and saved the day.

The alarm bells started ringing when the only ref I could find on caterhamparts was for the entire rear hub assembly at £1,300, which usually means that parts are not available separately.  If n/s part is damaged, I should really replace both sides, so that could mean £2,600, which is bananas.

Here's where blatchat came to the rescue in the form of a post from MarkTheGoose.  Mark's CSR had that same issue.  I  skimmed through Mark's post … the CC parts were that expensive … only available on demand … lead time could be months … … sh1te.  Titan were identified as the supplier and could make the part, but £800 per side + 2mth wait - still a horrible amount of cash for basically a bracket and a long wait.

Then a few pages on in the post, Mark wrote that he'd got in touch with a CSR race team - Luke Stevens from Team Leo's Motorsport make their own, to a stronger design the original and even keep some in stock.  I contacted Luke who had two 'damper clevis' parts remaining from the current batch.  I sent the old parts to Luke who extracted the wishbone pins and installed in to the new parts, which requires a lot of heat and a huge breaker bar.

Coming up to date, the new damper clevis parts are with me (pic [2] below).  I've also finished reconditioning the upper and lower rear wishbones, painted with por-15 and replaced spherical bearings, reconditioned the rear track rods with new rod ends,  new CV boots and re-greased CVs on driveshafts and … new nuts and bolts all round too (which excites me in troubling ways).  Just waiting for dampers to return before it all goes back together.  I might clean up and paint the rear brake calipers while I'm waiting.

Can hardly wait to getting out on the road again … lockdown has made this a verrrry long winter and hopefully spring and some sort of return to normality is beckoning.  It'll be interesting to see how the rebuilt dampers perform.  Will also be good to know that the rear and suspension / drivetrain on my CSR is now more of a known quantity and should in good shape for some years to come.

To other CSR owners out there - if you've not already read the post from MarkTheGoose and checked your damper clevises, I suggest you do so.  This may be a weak spot on the car and given the speeds they are capable of, it seems like a very good idea to make sure you've got no issues.

[1] Broken damper clevis - view from below, looking up at the failed lower damper bolt eyelet.

[2] New damper clevis parts, with wishbones pins installed.

cheers, Andrew.

[MarkTheGoose]

Andrew - thanks for the thanks  and so glad that my solution ended up helping you too

[nickh7]

That must have been a moment when you found that .

 

Great that its sorted and you can now get ready for a blating season safe in the knowledge that all is good back there

 

All the CSR owners are now jacking up theirs to take a gander

[vertew]

Yep, just really thankful I caught it before it failed completely - not a nice to think that the rear wheel could have collapsed at max chat, coming up a motorway slip road.

Definitely a good idea for CSR owners to take a close look.  Luke tells me he's getting 12 more of the stronger / bespoke 'damper clevis' parts in for next week, so hopefully, this will help keep more CSRs on the road.

[420R]

Could have been very nasty in the extreme.    Scary sh!t!!

[Baggiebird]

Well done to you for spotting this and spreading the word!!

[vertew]

Thanks guys, still feeling lucky to have found it in good time.  Many of us probably lean on our cars quite hard and definitely seems worth taking major assemblies apart from time to time to check all is ok.  I try to keep the mechanicals fresh with a sort of ongoing rolling rebuild / refresh.

Mark (above) mentioned some threads about prop shaft condition and re-greasing.  So, that's another thing to add to the list.  Bit of a pain in a CSR as it's enclosed.

Rear suspension / brakes all tidied up now, back together and looking much smarter with new / refreshed parts.  David Masters from Bilstein tells me dampers should be back next week, so should be back on the road soon!

I'll try post some pics when done + a part list.

cheers, Andrew.

[David Brown]

Andrew, what mileage has the car done? I had to take them off recently to drop the diff to allow me to get my failed prop shaft refurbed. Unfortunately couldn't get the bottom bolts out the dampers as they were seized so had to leave them attached to the dampers and disconnect the other screws/bolts. Clevis looked ok. 

[MarkTheGoose]

David, I think that Andrew & I had similar circumstances. Mine was a 2005 / 20,000 mile car. I think that Andrew's is also 15 years old and similar mileage ... Let's face it after the prop shaft incident and your troubles getting the diff on/off, you don't need more challenges. My instinct is that your's are OK, but it would do no harm to check them a few times a year - you can do it by lying on the ground, without removing anything ...

[richardhomer]

Thanks to Mark and Andrew for drawing attention to a potential rear damper lower attachment clevis weakness on the CSR. I guess all of us CSR owners will be checking regularly.

While talking CSR rear suspension, has anyone any idea how the lower wishbone outer spherical bearing joint could be enclosed to protect it from road grit and premature wear ?  I can't see how any rubber boot could be fitted.

[vertew]

@Mark - my car is just over 19k miles and 2005.  Suggest you take Mark's advice - luckily, the failure mode is fairly obvious - if you can see that the lower bolt clevis 'eyelets' are complete, with no missing pieces / signs of cracking, then the damper clevis should be intact.

My hunch is that the original damper clevis could be fine for typical / high-speed driving loads, but giving it a clout, as it might receive if you took a kerb (n/s rear) at speed, would represent a huge shock load.  So, if you do bump a rear wheel by mistake, then definitely check the Clevis!  I recall doing that with mine, but had it a long time now ... possibly.

@Richard - it's a good thought, though can't see an easy way of protecting spherical bearings either.  I coat bear metal supsension parts with Bilt Hamber Dynax UC, which forms a dry-ish rust preventative wax coating.  The bearing itself (NMB ABWT10) is stainless steel, so shouldn't rust, though the walls of the wishbone bearing socket do of course.  The wax won't stop road grit getting on the moving ball, but should help keep moisture / rust away from other parts.

cheers, Andrew.