General Tech Tensioner Pin

[KVH]

I made this a separate post because the question is so specific. I noticed that the backside of the tensioner pin that I received from Moss is concave. See pic. I seem to recall someone once saying that you’re supposed to “peen“ the backside of that pin to guard against it coming out. Naturally, my questions are whether that is correct and, secondly, how would I pin that pin effectively. Thanks for the help.

 

[mezy]

Just put some thread lock on it, if you peen it over it will be very difficult to remove if heeded in the future

 

[KVH]

My original is soldered into place. I think peening is to guard against catastrophic failure. I’m imagining that pin coming loose under load.

 

[CJD]

+1 to thread locker. Of course doing more cannot hurt.

 

[KVH]

Thanks. I used thread locker and peened the back as best I could. I wish I’d had the presence of mind to use Red, but I used Blue.

There’s always more to think about. I suppose that the worst would be that the timing chain would break, the car would stall and I need a new timing cover and possibly new cam gear and crank gear. Just thinking thru what it means if a chain comes off.

 

[CJD]

The chain will not come off, but it could slip a tooth if you have a LOT of miles on the engine when the tensioner comes off. The good thing is, assuming you are using normal cam lifts, this is not a valve to piston interference engine. In other words, the valves cannot hit the pistons unless you use are using a much higher lift cam. If the tensioner falls off, it will jam in the cover and make a racket that will get your attention immediately.

 

[DavidApp]

The tensioner can eat a hole in the timing chain cover. I found this when I had the cover off a couple of years ago. I did round off the corners of the tensioner.

David

 

[KVH]

Thanks guys. I like what I’m hearing. I’m headed to an old time machine shop to see what they think of my amateur peen job. I’m encouraged to hear about the likely scenario of a failure! Probably not so horrible, but also not likely. Though I wish I had used a lock tight stronger than blue.

BTW, When I was in high school working on my first TR, I forgot to put the washer between the tensioner and the cotter pin. I had a nice hole in the timing cover and a stream of oil running down the front of my engine. There’s nothing like learning from experience

 

[KVH]

My machine shop guy liked how the tensioner pin was peened on my new aluminum front plate, and felt that the lockwasher and locktite, blue as it is, should all be fine. Green light to all.

But guess what--l'll probably just use my old steel front plate with the welded pin. It seems quite suitable on careful review, and that way I won't feel like I replaced something for no good reason. And, besides, I'll be using, and not discarding, a vintage plate manufactured In England during the Triumph glory days.

 

[sp53]

Every engine I have taken apart had some kinda problem with the tensioner effecting the cover or being cut through by the chain. I remember a brief time about the 1980ites when the tension was NA.

A machinist guy suggest to use a piece of Teflon and to stick it on with JB. I did not trust his idea found a tensioner that was used and a little scared and just put that in place.

I am not sure if that whole tensioner system is flawed or there is a way to do the installation differently that a DIY should understand, but it seems straight forward. They always make me a little nervous when I am fitting the timing chain cover because everything is in the dark.

Heck I would have a gooped cover in my hands and then it has this spring loaded deal, I need to hold back and then get the cover over the crank and onto the block pins. I have never measured the distance between the cover and the pin, but it must be close, so the pin will not vibrate out. I have never found the pin out, but a lot of scaring.

steve

 

[KVH]

The tensioner will definitely wear a hole in the timing chain cover if there is no washer behind the cotter pin. I believe the tensioners are manufactured correctly and there is sufficient clearance if a washer holds the tensioner base in place.

But you have me wondering. I’m going to measure the length of each pin, the one on my aluminum plate and the one on my steel plate, and verify they are the same. I’m wondering if my welded one may protrude too far.

 

[CJD]

The problem in the 2000's was the tensioner was not hardened steel, so the chain would wear through it in short order. Even if they get the metal correct, the tensioner lives on the edge. It is important to polish the outside links of the chain so it will not have sharp edges to cut like a chain saw through the tensioner.

I'm like you, Steve...I don't think the teflon would last very long against the chain. It might be better to glue it to the inside of the cover, where the rubbing of the tensioner tends to wear it, although not as much as the chain wears the tensioner.

 

[KVH]

I bought my tensioner 8 years ago. Do I need to worry about the steel? It's a black carbon looking steel.

(Wait, by the time a weak steel one wears through, I'll be in my 90s)

 

[CJD]

I don't know of any easy way to know. Sending it off to have it hardness tested would likely cost more than the tensioner cost.

 

[DavidApp]

Don't they make hardness testing files?

David

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[CJD]

Yes, but like I said, they cost a lot more than a tensioner, for what will likely be a one use...also files are not the correct way, which is to use a Rockwell hardness tester. Those machines are pricey and their owners usually charge a good bit, unless you know an engineering student somewhere?!? Then, thin parts pose their own problems, making testing problematic.

I don't have an easy solution...and with my engine I just purchased the TRF tensioner and hope for he best. So far it is quiet!