What torques to use on chain housing?

logician · 10-05-2002, 07:36 PM

Hi,

I am in the process of putting back the timing chain housing in my '86 930. However, I can't find any specification for torque of the 3 M6 bolts fastening the cam shaft cover under the chain sprocket, or the 5 M8 nuts attaching the chain housing to the block. Would anyone know what torque to apply to these nuts and bolts? I have found in a previous post, some standard torque values for various size bolts. However, I don't know if these "standard" torque values should be used in this case, or if these torques are appropriate for both bolts and nuts. There is a paper gasket between the cam shaft cover and head and another between the chain housing and block. Does the presence of a paper gasket affect the torque value? Any help would be greatly appreciated.

Thanks!
-Juan

Eric Coffey · 10-05-2002, 10:33 PM

Not sure about the camshaft end plate bolts, but I'm pretty sure the 5 chain-housing-to-crankcase bolts should be torqued to 18 ft/lb. Be sure to verify before using that figure though!

Superman · 10-06-2002, 07:42 AM

I would trust the standard values for those fasteners, if you don't find a more specific reference. I might put a little more torque on the litte cam thrust plate bolts since the gasket under them wil settle. And here's a tip you should not ignore (like I did): Be careful to make sure the gasket is positioned properly underneath that plate. It tends to slip down, gravity holding it against the bolt shaft/threads as you install it. If you let this happen, it will leak. I had to re-do mine, a pain in the butt. A HUGE pain in the butt on a Turbo. Spray some of that copper gasket dressing on it and 'stick' it into position so that it will not leak.

logician · 10-06-2002, 10:51 AM

Hi Superman,

Thanks for the warning on the gasket. I coated mine with oil to get it to stick into position, although it seems like it could have shifted in the process of assembling it. Regarding the torque on those cam cover plate bolts, the bolts are M6 8.8, so according to the table, that would require 7 ft-lbs. That doesn't feel like a lot of torque to me. Did you use a torque wrench when you did yours, and if so, what value did you use?

-Juan