I found more issues while waiting for my gears to arrive . I had 2 shocks, even though built carefully last month that didn’t seem to seal no matter what.
it was a poor design to sandwich a rubber diaphragm AND a rubber o-ring. In my years as mechanical engineer / designer with similar parts we never practiced this for our environmentally resistant tough parts.
At first I mistook this to be the cause and built the shocks anyway.
2 leaked no matter what I do.
I ordered a 2 more replacement caps as I wondered if I stripped or cross threaded the plastic shock caps. Eventually this is the root cause
The one on the right is horribly malformed, and it is a sign of poor extraction / ejection from the molding process. Upon careful inspection even the one on the left is also deformed even though my 1 single picture above does not show it clearly.
In effect the internal surfaces important to seal against the rubber diaphragm was never flat or true enough. There was plenty of plastic shrinkage / sink marks to cause a concave inside. Again darned hard to photograph.
The luck that I have with this kit / brand is weird. I actually bought 4 spare shock caps, added with 1 in the kit that was deformed and 1 from the spares I threw away 2. It’s a good thing I bought spares for the heck of it. It was actually out of courtesy to cover the Taobao shipping for them to bundle in the 1st batch of replacement diff ring gears. I could’ve insisted on getting just the gears for free but thought what the heck I’ll just order some spare parts.
Am I going to discover more QA/QC issues?