Chain tensioner leaking

[Zolpidem]

Hello mates, the chain tensioner housing of my 2400 is leaking. I bought from Dinoparts the seal but I wonder weather I can easily change it without messing up the mechanism of the tensioner and the distribution thing…
What is your experience?
Thanks
Ludovico

[ThomasK]

There are two seals:
- one paper seal between head and tensioner
- an O-Ring under the tensioner cap.

While you can unscrew the cap and then see and can exchange the o-ring, the paper seal can only be replaced when the head is disassembled.

There is another thing: you still have the old version of the cap without counter screw. As this version can cause that the chain looses tension as the tensioner can move into the cap, already in early days this wa upgraded by a counter screw.Highly recommended to avoid problems and damage.

[Luis A]

... the paper seal can only be replaced when the head is disassembled.

Thomas; what prevents the tensioner to be removed entirely when the head is in the car?

[ThomasK]

The end with the gear can’t be dragged out to the outside of the head and can/will fall into the engine when you remove the outer part.

[Luis A]

Well, you made me look. I thought I had done this without having the head off so I looked at my photo record and indeed I did take out the assembly to carry out the additional bolt modification, re-gasket it and replace the O-ring. I don't recall the details of how I did it but there were no extraordinary means such as removing the head...

[ThomasK]

I have no idea how it works to keep the inner part in place and to get it back in into the outer part with heads on, as I have it done always when the heads are taken apart but would be interesting to hear if/how it works.

[Dario]

If I remember right, you assemble the tensioner on your bench and compress the spring before tightening it. Then, you bolt the pre-loaded tensioner on the head and release tension once it's on. Good tip on the counter-bolt, it was a Ferrari "upgrade" for the 246 at the time. Concerning the oil leak, I confess to a small dab of silicone to help the o-ring on the one tensioner that it upside-down. Since it is always full of oil, it is easy for it to drip on the exhaust manifold.

[Gaelicguy]

I do not have the tensioners with the added set screw/bolt. Is this an after market part you can buy or is it something that can be “ homemade” I didn’t see it in the parts books. But the I only have the 2.0 manuals.
I’ve searched in the past for this topic and just found this one.
I’d like to get it done when I do the engine rebuild.
Thanks
Michael