Torque Specs for your rear Suspension | Bushings (values are in here!

[ONDEMAND]

Going to tackle RTAB's this evening and realized I have no info on proper ft/lbs. for the rear trailing arm bolts. I believe these are M12 bolts and collar nuts, one in the wheel carrier and one in the subframe.

Anyone have specs for these bolts or own the bentley manual and can do me a solid by looking it up?????

Searched and no DIY on here or E90post so if I can get the info Ill be glad to rehash it here for others with a DIY.

If nobody has the info Im thinking 70-80 ft/lbs.??????

Also these OEM bushings have to be compressed prior to installation and I have the bavAuto/Koch bushing tool. The limited instructions listed with the tool set state the bushing original diameter of 46.5mm they should be clamped | compressed to 45.3mm before installation. Can anyone confirm this spec???

http://kochtools.com/index.php?p=product&id=258

Going to pick up a caliper to measure with today.

Any help appreciated

[ONDEMAND]

So for anyone searching "workshop-manuals dot com" has maximum torque specs per fastener size.

4 Tightening Torques > 00 Maintenance And General Data > 3 AZD M12 And M12x1.5 - Maximum Tightening Torques Ac

For the M12x1.5-10.9 that passes through the RTAB we use either 100Nm (74 ft.lbs) "ZNS - silver" or 123Nm (91 ft.lbs) for "ZN - yellow" depending on the surface coating (colour) of the fastener.

I interpret this to mean (correct me if Im wrong):

ZN = Phosphor coated | Yellow
ZNS = Cadmium plated | Silver

Description of coating | surface color from the workshop manual

"Surface color yellow (ZN): Applicable only to shank screws with
metric coarse- and fine-pitch threads according to DIN 13-28 and nuts
with nut height 0.8 x d according to DIN 934 and exclusively for a µ tot = 0.125 (screws phosphatized, nuts without subsequent treatment or galvanized. Lubrication condition: unlubricated and also oiled)"

"Surface color silver (ZNS): Applicable only to shank screws with metric coarse- and fine-pitch threads according to DIN 13-28 and nuts
with nut height 0.8 x d according to DIN 934 and exclusively for a spread of µ = 0.09 to 0.15 (screws cadmium-plated, nuts without subsequent treatment or galvanized. Lubrication condition: unlubricated and also oiled)"

Now just need to figure out which "surface color | coating" Im dealing with and apply the correct torque value. From memory I recall all fasteners in the rear axle | suspension assembly appearing silver. I always assumed all these fasteners were simply galvanized steel or alum. based on the color and texture.

[ONDEMAND]

Found more direct info in the same online manual - I'll be using 100Nm for the RTAB fasteners.

ADDITIONAL SPECS BELOW PER AREA | COMPONENT

33 32 Control Arms and Struts Type Thread Tightening specification Measure

1AZ Trailing arm to rear axle carrier E81, E82, E87, E88, E90, E91,
E92, E93 M12 Replace nut tighten in normal position 100 Nm

2AZ Trailing arm to wheel carrier E81, E82, E87,
E88, E90, E91, E92, E93 M12 Replace nut tighten in normal position 100 Nm

3AZ Control arm to rear axle support E81, E82, E87, E88, E90, E91, E92, E93 M12 Replace nut tighten in normal position 100 Nm

4AZ Traction strut to wheel carrier E81, E82, E87, E88, E90, E91,
E92, E93 M12 Replace screw tighten in normal position Jointing torque 100 Nm Torque angle 90 °

5AZ Control arm to rear axle carrier E81, E82, E87, E88, E90, E91,
E92, E93 M12 Replace nut tighten in normal position 100 Nm

6AZ Control arm to wheel carrier E81, E82, E87,
E88, E90, E91, E92, E93 M12 Replace screw tighten in normal position Jointing torque 100 Nm Torque angle 90 °

7AZ Toe arm to rear axle carrier E81, E82, E87,
E88, E90, E91, E92, E93 M12 Replace nut tighten in normal position 100 Nm

8AZ Toe arm to wheel carrier E81, E82, E87, E88, E90, E91, E92, E93 M12 tighten in normal position 100 Nm

9AZ Camber arm to rear axle carrier E81, E82, E87, E88, E90, E91,
E92, E93 M14 Replace nut tighten in normal position 165 Nm

10AZ Camber arm to wheel carrier E81, E82, E87, E88, E90, E91,
E92, E93 M14 Replace nut tighten in normal position 165 Nm

11AZ Tension strut to body E81, E82, E92 / Except S65 M8 24 Nm

12AZ Tension strut to compression strut E81 M12 Jointing torque 56 Nm Torque angle 90 ° E82, E92 /
Except S65 M12 Jointing torque 100 Nm Torque angle 90 °