Yep, the quality of the aftermarket rubber parts sux.
I'm still using the original 32-year old shifter boots and they don't have a single rip or tear on them. The brand new Crown boot I put on my 360's bell-housing lasted about 4 months.
I wish I had an answer for you, but it seems Crown and Omix are the only suppliers of some of these more obscure parts. I've decided to treat some of these parts like normal maintenance items, like changing filters, or rotating tires. Just buy extras and replace them as needed, I guess.
I gave up on the rubber shifter boots. Went through 2 in less than a year. I ended up going to an upholstery shop and had them make me some out of vinyl backed with a waterproof boat material. It was kind of expensive but works way better.
1979 CJ7 258 / 4.0 head / J20 power Steering / T150 Dana 20 / EMU YJ 2" lift / Custom front bumper
Looking for : Please PM, Carter 2 barrel Carb before you through it out
I looked over some of the rubber pieces on my CJ-7 since it was restored and back on the road since 2011 and many of the aftermarket rubber and rubber/foam parts are deteriorating.
Steering column seal through the firewall is breaking apart.
Bell housing fork boot is ripped.
Shifter boot out of the trans is heat damaged and deteriorating.
Shifter boot on the trans cover is holding up well.
TC shifter boot on the trans cover is holding up well.
Rubber boot for manual shift rod through the firewall is ripped.
I believe Crown Automotive makes everyone one of them and shame on them for allowing inferior parts to be made in China. And that's not all, my Crown Automotive defrost knob just came off the end of the cable yesterday. Jeezish H...
Its unbelievable that they sell such crap. I'm writing an e-mail to them shortly but must first take photos for proof.
I've had similar problems with the control knobs too. The one for the fresh air vent came of within a month or two. And it wasn't from me pulling on it because I never use that one. It just fell of. The one for the heat came off a few months later. I ended up buying black aluminum knobs that I install with a set screw. No more problems.