Retainers do not need removal to inspect, all you need to pull is the valve cover.

Broken retainers, even slightly broken, are easy to spot it you know what to look for.

 

It just depends. Like Billman said, the original retainers can be good for a long time and can take more abuse than you think.

If you want the piece of mind in knowing your retainers can take an over rev then replace the intake ones with AP2, reassemble, and valve adjustment.

If you just want to replace them if they are damaged, inspect and check adjustment then put it back together if they're good and don't worry about it.

Mine were fine at 83k miles on this engine, and my last one was fine at 150k miles too. I replaced them on this one for the added piece of mind since I do autocross it as well. Same reason I had a friend tig weld the upper control arm mounts. Just in case.

 

So when a retainer is cracked it tends to walk up the cotter giving the valve and cotters a sunken look, correct? But the cracks begin typically at the bottom center of the retainer, where it's hardest to see. As I'm picturing it in my mind, I don't see it unlikely for there to be a crack that's just starting and is therefor not visible through the springs and also not showing obvious signs. I'll pop my valve cover off to get a better idea, should make more sense then. Thank you for the replies, everyone. I know we're beating a really old dead horse but someone's going to read this lol

 

I checked mine at the weekend and I think they look ok, based on other pics I have seen. Can anyone give them a second opinion for me please?

 

None of those "look" cracked to me given the pictures but angles can be deceiving sometimes. Below is a picture that @Billman250 posted in another thread. Cracked retainer is on the right and you can see how the keeper is more sunken into the retainer in that one.

 

None of yours appear to be "curled" upward, so you may be ok.

The cracks propogate from the bottom, though. Maybe try using an inspection mirror to see the bottom of them to be sure.

Or just change them.

 

I replaced mine. Intake side only, of course. I didn't trust myself to inspect them. And if I accidentally over-rev the engine, now I have that extra bit of insurance.

They're not expensive and changing them isn't a horrible job. Just tedious. Now I never need to think about them again. Which is worth it, for me.

 

Preventive maintenance is the best maintenance. Retainers are a known breakage item; the OEM TCT is known to wear out.

-- Chuck

 

In which way does the OEM TCT wear out? I'm pretty sure it's the stuff the TCT interacts with that actually wears, ie guides and chain.

 

TCT wears out internally in areas that don't contact anything outside the TCT itself. One the TCT wears out the items you mention start wearing faster.

Surprised you missed the TCT discussions the past 8 years you've been a user here. Some guy known as @Billman250 has developed a bullet proof replacement for the OEM TCT (you may have read about him here).

-- Chuck