I found a missing spring retainer on my '67 CL77 shock. Closer inspection and shock disassembly revealed that the missing retain had actually fractured and the top portion departed. The remaining retainer was cracked about half way around. I posted pics in the Parts Wanted Section for those who might be interested.
My question is, is this a common failure? I flog the bike pretty hard at least twice a year in the Motogiro and this year it got flogged 3 times. Often the course includes some pretty rough dirt roads. So the shocks take a beating.
If this is abnormal, then I'll just locate a new pair, inspect the other shock and carry on. But if others have experienced this failure and it is common, then I may either machine new retainers from stainless or buy a pair of Hagons.
Thanks,
Rob
CL77 Rear Shock Spring Retainer FailuresWell, it would appear from the lack of replies that nobody else has suffered this type of failure.
Ed did respond to my parts wanted ad, but since then a friend said he had a pair I could have for parts. But of course, he cannot find them. So today, I decided to simply machine new retainers. The weak point in the retainer is the narrow web between the two bore sizes of the retainer and the OD of the portion that enters the spring. It is maybe 0.062? I did not measure it. So, I modified the dimensions to maintain proper function, but put a little more meat into that web area. The retainers are chromed pot metal. I machined the new ones from aluminum barstock. Only testing in the field will determine if they will hold up over time. I have to repaint the bottom shock shroud since it had all the paint scrapped off one side when the top shroud went cockeyed after the retainer top half separated. If that is confusing, that's because I painted the bottom half of my shouds. The PO of the bike wire brushed the rust off the chrome and pretty much ruined the finish. Now top and bottom shrouds are black on this bike. I'll post pics of the assembled shocks when the painting is done and I can reassemble. Here are the retainers after machining and before splitting on the saw. You can see what was left of the old retainer below the two new ones.  I split them on a saw and here you can see the difference between the original web (you can just see a crack in it) and the web in the new retainer. The pencil is pointing to the area on the new retainer half.  This shot is a bit closer so you can see the new web is a bit bigger.  What I did to increase the web was reduce the amount of engagement that the retainer has in the spring. this let the surface of the top flange move downward. I lowered it 0.062". So here are the two new retainers and what I had work with for dimensions.  regards, Rob Thanks guys. I assemble the shock today and the new retainers fit like a glove.
I pulled the other shock off the bike and removed the OEM retainers. Both were in perfect shape. No signs of cracking or even a place for a crack to start. Should not be a faulty retainer since they are cast separately and the chances of two faulty halves being picked up during the assembly process seems remote to me. Can't see how one shock would take a worse beating than the other. Could be the shock came from another bike and had been in a wreck. We'll never know. Like I said, only time will tell if these new ones will hold up. I was happy to find the other shock had no damage. Here's the shock after assembly. Could have polished the aluminum to look like chrome, but I kinda like the business look of machined aluminum.  regards, Rob Thanks again. These were really pretty simple to machine. I was a class A machinist in my youth befor moving on to engineering. So, I did stuff like this all day as a developmental machinist in an Atomic Power Lab. We did prototyping work for the US Navy. I realize for a hobby machinist this might be challenging, but it is quite simple if you take your time, study the example piece and measure everything twice.
I have friends that bust my chops because I make this stuff rather than just buy a new part. My answer to that is "Where is the fun in that?". I like to share this stuff because it may help the next guy solve a similar problem. regards, Rob
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