What type of chain tensioner is this?

[78sc]

Hello,

Doing some service to my engine while it's out and popped the chain cover to look at my tensioner. Was considering buying the safety collars but discovered that they were already installed. I wanted to make sure they were on tight so I pried gently upder the collar and on top of the tensioner and the shaft moved upwards about 1/8th of an inch (tightening the chain).

Two questions: (1) Did I ruin the tensioner by prying there? (stupid think to do, I know) and (2) Do these type of tensioners require any adjustment? I don't see any adjustment screw/lock nut or anything besides what looks like cap on the left hand side of the tensioner body.

Sorry for the bad pic, but hopefully you can get the idea. I'm worried that I might have knocked something out of whack. I did a seach, but didn't find anything that looked like this.

Thanks,

Phil

[Diesel_mp5]

Ooooooohhhhhh I miss my sc...... Looks like a orginal Sc style tensioner. It is designed to move up and down. There are no adjustments that need to be done. The safty collers look a littel high on the shaft, but you need to check with one of the more pro guys. I had mine installed by a Porsche shop here in Las Vegas.... Carls Place... He said i would know when it failed and not to mess with this,,, lol.. Good luck. Diesel_mp5

[78sc]

Thanks Diesel. I also thought the collar looked a little high on the shaft. Anyone else have an opinion or comment on what kind of tensioner this is or if it requires any adjustment? Also, how would I check for proper tension on the chain?.

Phil

[carmen78sc]

Yep, stock 78sc tensioner with a safety collar. You didn't hurt anything by prying up on the collar. That collar's just there to keep the chain from going so slack during a tensioner failure that the chain can jump sprockets and cause expensive engine damage. Believe me, that little allen set screw isn't going to keep the collar from sliding on the shaft when the tensioner goes!

The tensioners are not adjustable; so, if they're still good, chances are you have the right chain tension. This same setup was in my '78 when I got it. During my upgrade to the pressure-fed tensioners, I found one of the originals was bad and was essentially just riding on the collar! It turns out there was a little extra noise in the back, but I just thought it was noisy bearings in the smog pump (which was contributing, too). It's subtle.

Here's what I did and you might try: use heavy duty zip ties and loop a few around the chain near the tensioner to keep the chain taught. Slide the tensioner out and press on it with your fingers. I could move the collapsed one in and out with finger pressure. The other took considerable force to compress. Do one at a time so you don't risk letting the chain go slack (bad, could require retiming the cams).

Tom