I am rebuilding a 1956 Jaguar XK140 engine and have a new ROLON hydraulic chain tensioner for the lower timing chain. Ken Jenkins of the Jaguar Enthusiasts Club assures me it is the right product. Together with the body, it consists of the circular plunger with a chamfered rubber end piece, a spring and (at the inner end of the spring) a circular hollow tube with an angled, serrated slot.
The serrated slot allows the unit to be locked up tight by compressing the spring and rotating the end piece.
In order to fit the unit against the lower timing chain, it is necessary to first release the spring (because you cannot release the spring after the unit is bolted onto the engine) but I find that the circular plunger does not have a full free travel but seems to snag on the serrated plate. What am I not doing?

 

Or you checking with it mounted? Doesn't travel right unless mounted.

 

Yes I have fitted it but it seems reluctant to move in and out on the spring.

 

Hello,

I used the same tensioner as you did.
Rebuild the motor last month, and it seems to work fine.
And indeed you can't fit it with the nylon piece in place.
So I kept it compressed by hand while fitting it.
you can only mount it one way, or the plunger gets stuck on the plate.
Seems you have it the wrong way then.

regards,
Peter Jan