Rear trailing arm bolt torque?
 

Hi,
I've replaced my trailing arm bushings, but can't find a torque spec for the bolt that runs through said bushings in the Spec Book.

Anyone know what it is?

Thanks!
Colin

Hmmm. Maybe it's "control arm to cross tube" 60Nm? Does that sound right?

Colin,
I checked the torque chart in the MMCC book, and a 8.8 M14X1.5 zinc plated bolt has a suggested torque of 103 ft/lbs or 140 nm.
Hope this helps.
Regards,
J.P.

Thanks JP for looking it up. What is the MMCC book?

It is a 14x1.5 8.8 bolt, but it is pinching the rubber bushings and sheetmetal bracket holding the trailing arms. I'm worried if I torque to the bolt's spec, it might crush the bracket. But there are only two 14x1.5 bolts listed in the specbook for the rear suspension, so I think the 60Nm listing must be the one.

Colin,
Does the bushing have a sleeve in the center were the bolt goes through? The mounting brackets should tighten agaisnt it.
The MMCC book is Metric & Multistandard's metric supply book. It has a section with torque spec's for all metric sizes, thread pitch, grade and finish (zinc plated & black oxide). When the bolt has a zinc finish the torque spec is lower due to the hydrogen embrittlement factor. Some manufacturers don't warranty bolts of 10.9 and higher if they're zinc plated.
Regards,
J.P.
Ps. the 140 nm figure is the ideal setting for that bolt size (8.8 zinc finish); application has a lot to due with that figure. In your case, Porsche may have a lower #.

Colin,
I just checked the Volume 1-2 (1965-72) of the factory manual and the torque figure shown is 86.8 ft/lbs. The figure is in vol. 1 section R page 76.
Hope this helps.
Regards,
J.P.
Ps. Sorry I didn't give you this info before; I couldn't find the factory book, the MMCC book was on my desk.

Colin,
The factory book states: "Caution: The hex bolt may be tightened only after the vehicle has been placed on it's wheels since otherwise the twisting action capability of the Flanblocks would be exceeded."
Flanblocks is their terminology not mine. I thought they were called bushings????
Regards,
J.P.

Thanks JP!

Colin,
I think the M 14X1.5 bolt you saw in the spec book may be the shock to banana arm bolt. I can see why it would have a lower torque due to the fact it's threading in aluminum.
Glad I could help.
Regards,
J.P.