Fastener Torque Error in Bently Manual?

[dkirk]

I’m going to install new engine/transmission mounts in my ’88 911 coupe. Reviewing the torque specs in the Bently manual, there seems to be a discrepancy in the published fastener figures for the front versus the rear mounts. The engine end states the M12 Crossmember mount to body bolt gets torqued to 25 Nm.



The transmission end M12 gets torqued to 80 Nm.



Shouldn’t both front and rear M12’s be torqued to the same value of 80 Nm? Seems like some figures were swapped in the stated torque specs. Experts please advise.

[Classic 911]

Originally Posted by dkirk

I’m going to install new engine/transmission mounts in my ’88 911 coupe. Reviewing the torque specs in the Bently manual, there seems to be a discrepancy in the published fastener figures for the front versus the rear mounts. The engine end states the M12 Crossmember mount to body bolt gets torqued to 25 Nm.



The transmission end M12 gets torqued to 80 Nm.



Shouldn’t both front and rear M12’s be torqued to the same value of 80 Nm? Seems like some figures were swapped in the stated torque specs. Experts please advise.

Yes both M12’s get’s 80Nm:

Crossmember mount to body
25Nm (being the no.5 part, no. 1 nut torque’s to 25Nm)
Crossmember to crossmember mount
80 Nm



Crossmember mount to body 80Nm
Crossmember to transmission 25Nm


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[dkirk]

Thank you. Another error in the Bently manual noted.

[David Inc.]

The crossmember mount to body is the actual engine mount being bolted to the body with the two M8 bolts. That's 25Nm. The crossmember to crossmember mount is the M12 into the engine mount at 80Nm.

I think the trans mount is written differently because the trans mount is integral to the crossmember, where the engine one is a separate thing.

[stownsen914]

As it looks like others noted, the M12 bolts seem to be correctly listed as 80 Nm