Transmission to Engine M10 Fasteners Torque Spec?

[frankc]

I hate to ask such a simple question here, but I'm trying to find the torque spec for the four M10 fasteners (3 nuts, 1 bolt) that hold the 915 transmission to the engine. I looked in the factory workshop manual, the "Tech Spec" booklet, Bentley, 101 Projects, Haynes, and searched the web, but I can't find this number. The closest I found is 46-48Nm (34-35.4ft-lbs) for the separate starter M10 nut.

Does anyone know where I can find the torque value for these four fasteners?

Thanks,
Frank

[Jesse16]

Wouldn't they just be the "typical" torque numbers found in Bentley for every engine and tranny fastener ?
M8 - 25 NM or 18 ft-lbs
M10 - 42 NM or 30 ft-lbs.
M12 - 80 NM or 58 ft-lbs.
Just torque based on size normally. Can go less if not structural is how I view it.
I rarely torque maintenance items but engine fasteners get more attention if I've got it out of the car as I'm taking time and being clean.

[Lapkritis]

Would recommend a little blue loctite on the threads here. Dry assembly can gall and come up short on fastener torque.

[frankc]

Originally Posted by Jesse16

Wouldn't they just be the "typical" torque numbers found in Bentley for every engine and tranny fastener ?
M8 - 25 NM or 18 ft-lbs
M10 - 42 NM or 30 ft-lbs.
M12 - 80 NM or 58 ft-lbs.

Most M10s that attach to the engine case are 40Nm (30 ft-lbs), so that sounds reasonable, but then there is the Starter M10 nut at 46-48NM.

I just find it odd that Bentley has left out such a fundamental torque setting because they are usually pretty good about listing the specs needed per section (although I have found them to be wrong on many occasions).

[Speed Buggy]

Well Frank, what did you do? I saw the starter torque too but nowhere else but the generic torque chart.

[frankc]

I did end up finding the torque values for these fasteners in 911SC Bentley when I was looking for something else. I don't have access to the Bentley manual at the moment, but check the the section that covers engine removal and separating the engine and transmission - I think it may have been there.

[Speed Buggy]

OK, thanks. I found a 33 ft-lbs in the starter install section. I used that, it was close enough to the generic 10mm torque that I felt that was good. Cheers, Mike.

[Walt Fricke]

Well, I have never measured the torque on these. Just use a 17mm wrench and tug hard. Wrenches have lengths which kind of set the torque you can apply, so overtorquing is unlikely. I've never had one loosen. This is not like head bolts or cam carrier or case through bolts or rod bolts.

Of course, torqueing to spec won't hurt anything. Just takes a bit more time.

[Speed Buggy]

Thanks, on the driver side bottom I had to use the calibrated arm method. Couldn't get a socket on it and no crowfoot. Cheers.