Tom Pultz

Sorry, but the attached picture does not show the roller in question, which would be below the cam tensioner (further to the right in the image), only the metal one for the balance belt and the upper plastic one for the cam belt.

flash968

i was responding to the comment jdemas made in post #7 about the absent one in my serarch of belt pics, i looked at a bunch - i saw what i thought was the pic in question, and it was missing the idler (turns out it was a pic of somebody's belt job missing that idler) - the one he linked to does have that idler on it, hiding behind the hose

i also do not have the one you are talking about, though that does look like it would be a good one to have in there

Thom

Any idea why the 2.7 and 968 do not have this roller while the S2 (with almost the same block) has it ?

flash968

in looking at it, i'm a bit surprised they deleted it - seems to me it would be a good way to limit belt slap under torque

RajDatta

Thom, pretty simple. Hydraulic tensioner with continuous tension compared to spring loaded tension that is setup for static tension. That is the major difference between both setups. 968's can make up for some slack because of their hydraulic/active design while the other ones remain static.
Raj

Tom Pultz

Is the 968 tensioner retrofittable to other engines? If so, would it be worth doing? I think the hydraulic tensioner was implemented to increase the mileage interval between changes from 45K to 60K, and probably improve water pump reliability... but it seems like nobody goes that long anyway due to the continuous on-going problems with balance belts.

RajDatta

Tom, there is a stud in the block on 968's that would need to be tapped in order for it to work. The swivel mechanism is completely different. The tensioner works on this stud. I will try to take pictures as I am in the middle of a belt change.
Raj

Jim Demas

Tom....

But I believe that the timing belt interval has now been changed on the 968 to 45k or 4 years. I wouldn't go 60k!!

I think that in order to try and use the hydraulic tensioner you would have to also fit bracket 944.105.173.08.

-- Jim

Jim Demas

Tom & Raj...

Here is the picture of the stud for the tensioner lever.

- Jim

RajDatta

Awesome!
Thanks Jim.
Raj

Jim Demas

Guys...

At the top of the tensioner lever... there is a small round tan colored "pad" made of plastic or ceramic... and the hydraulic tensioner plunger pushes into it.

This ceramic/plastic pad is not listed as a replacement part in the PET. Anyone know if this part can be had separately?

-- Jim

RajDatta

Jim, I hope you didn't lose it but if you did, let me know. I might have a replacement one for you.
Raj

Jim Demas

Raj...

Mine looks like it has a hairline crack in it. Do you really have another? I would be very appreciative if you have one!

-- Jim

Tom Pultz

This thread has been "good" for Jim's "post count" which has increased by about an order of magnitude. I'm sure he wishes it were otherwise though and his car was back on the road!

Damian in NJ

I'm impressed he's a lifetime member with 20 posts!