QUOTE(bbrock @ Mar 6 2021, 04:11 PM)
QUOTE(Superhawk996 @ Mar 6 2021, 11:59 AM)
QUOTE(bbrock @ Mar 6 2021, 12:38 PM)
Anyone know the torque spec for the nuts securing the rubber mounts? Don't see it in the factory shop manual.
@bbrock I believe it is 21.7 Nm per Hanes manual (Engine support nuts - Body).
As a 2nd rationaltiy check here is the standard torque table for black oxide fasteners.
26 Nm for an M8 grade 8.8. I'd go with the Haynes spec.
That torque spec in Haynes is for the outer bolts that attached the steel support to the body. And if they say Nm, they are wrong. The factory manual clearly specs those bolts as M10 and 21.7
ft.-lbs. Way too much for an M8 bolt.
I wound up using that exact same torque chart you found (almost). The table you reverenced is for untreated screws (black finish). If you scroll down to the table for zinc plated fasteners, it speces 17.7 ft.-lbs. I was guessing 18 ft.-lbs. so pretty much spot on. I didn't know if there would be adjustment for the rubber mount factor but as I thought about how they are made, there shouldn't be. Anyway, I went with 18 ft.-lbs. which I think should be fine.
@bbrock You are correct Haynes is 21.7
ft-lb and you are correct, that is a bit high for an M8. I had assumed the units to be Nm. That is why I did the standard torque check as quick 2nd check for sanity. Yup, 26 Nm for a M8 black oxide fastener -- plausible.
Agree, plated fastener is slightly lower torque than black oxide but now you're splitting hairs for this application.
Honestly, I've never used torque wrench on those rubber isolator bolts. Torque spec is Good N' Tight. They are a reasonably rigid metal to metal joint. If you were actually torquing against rubber in the joint, you would never get anywhere near 20+ Nm of torque.
Bottom line - you got it done!
And for the record 21.7 Nm = 16 ft-lb. What's 2 ft-lbs amonst friends in a non-critical application.