cam tensioner stud replacement

[britmanjohn]

I'm doing the belts and rollers on my 924S and having read all the threads/clark's etc am replacing the cam tensioner stud also.

I can see the torque setting for the cam tensioner retaining nut is 45 Nm. However does anyone know how tight the stud should first be screwed into the block, and the torque of the nut that then threads on the stud and tightens up against the block? (This is the nut that is sandwiched between the block and the tensioner roller)

[bazar01]

Originally Posted by britmanjohn

I'm doing the belts and rollers on my 924S and having read all the threads/clark's etc am replacing the cam tensioner stud also.

I can see the torque setting for the cam tensioner retaining nut is 45 Nm. However does anyone know how tight the stud should first be screwed into the block, and the torque of the nut that then threads on the stud and tightens up against the block? (This is the nut that is sandwiched between the block and the tensioner roller)

I would use a "blue" Loctite thread adhesive on the stud. Do not use red as it is permanent.

[John_AZ]

The stud, if we are talking about the 10mm x 106mm (NLA) or x 101mm (short) most often sold.

or get your own ( see footnote 3 in Camshaft / Balance Shaft Belt Information )

and discussed Short tensioner stud? - Rennlist Discussion Forums

should fall into the "all other" bolt tensions. M 10 Tightening torque NM 40 + 5 ( about 30 to 33 Ft. Lbs.)

Per Clarks Oil Pump installation page:
Clark's Garage Home Page

Otherwise I am not sure.

John

[britmanjohn]

Thanks for those tips!

And yes John that is the stud I was referring to.

45 Nm seems a sensible figure. I was thinking to do that if there was no other specific torque value available ie the same as the tensioner retaining nut .

Cheers!

[bazar01]

Originally Posted by britmanjohn

Thanks for those tips!

And yes John that is the stud I was referring to.

45 Nm seems a sensible figure. I was thinking to do that if there was no other specific torque value available ie the same as the tensioner retaining nut .

Cheers!

yep, M10 needs 30-40 ft-lbs or 42-56 Nm.

[MrTibbs]

Hi,

ressurecting this thread with an additional question. I have the auto spring tensioner on my 924S. When changing the belts for the first time the thread on the upper thread stripped (I wasn't even torqueing it that high).

Are the 3 mounts for the auto tensioner studs (I'm guessing they are), and are they the same as the one for the eccentric roller tensioner? or are they permanent parts of the engine that I'd need to cut a new thread into?

Thanks
Mike

[John_AZ]

Mike,

The spring tensioner can be removed to fix the stripped thread. Use caution and do not go to deep if you drill.



Use a quality thread repair product---A thread insert should work.

The nut is tightened to 20Nm or 15 Ft lbs.

Optional (best)

++ TIME-SERT Threaded inserts for stripped threads, threaded inserts, thread repair stripped sparkplug's, Ford sparkplug blowouts, threaded inserts threaded, repair stripped threads, stripped threads, inserts threaded inserts, Ford spark plug repair,

GL
John

[Rasta Monsta]

Need to throw out a comment on this one regarding stud installation. IMO, the stud itself should not be torqued, but hand threaded until barely bottoming out. 30 for the retaining bolt sounds reasonable, though.

[MrTibbs]

Thanks guys. I'm pretty sure it's the thread on the stud that's stripped (and only on the section where the nut tightens) as I can screw the nut on and off, just not tighten it very much.

Given people's experience with backing studs out of the block (doesn't look fun) I think the best option might just be to add a couple of washers and another nut onto the good portion of stud thread (basically using the original nut as a washer). If it doesn't need to be torqued very tight I assume this will hold it fine. I've only just got the car back on the road after a couple of months of parts-hunting so keen to avoid the potential for giving myself another long job.

Mike

[bazar01]

Originally Posted by MrTibbs

Thanks guys. I'm pretty sure it's the thread on the stud that's stripped (and only on the section where the nut tightens) as I can screw the nut on and off, just not tighten it very much.

Given people's experience with backing studs out of the block (doesn't look fun) I think the best option might just be to add a couple of washers and another nut onto the good portion of stud thread (basically using the original nut as a washer). If it doesn't need to be torqued very tight I assume this will hold it fine. I've only just got the car back on the road after a couple of months of parts-hunting so keen to avoid the potential for giving myself another long job.

Mike

It should be fine to just put washers or spacers to avoid the stripped section and still be able to snug the nut tight. There are two more fasteners that are good anyway and they should hold up.

[MrTibbs]

Thanks Bazar, that's what I figured. Unusual for a thread involving belts not to have loads of replies saying don't start the car until you've done X, Y and Z.

I'm learning all the time with this car (1st car I've had that's merited doing proper maintenance on it) and at some point I might take the engine out and will time-sert the stud hole then. Need to find a house with a garage 1st.

Mike