how tight trailing arm bolt
Same with front A arms.
Race Director
Joined: Aug 2004
Posts: 10,628
Likes: 132
From: Duvall, WA
Yep. Or you can stick a socket between the bottom of the trailing arm and the pocket so the trailing arm is lifted to the position where it would be if it were resting on the ground.
Race Director
Joined: Feb 2006
Posts: 12,239
Likes: 19
From: Chino CA
Thread Starter
Melting Slicks
Joined: May 2003
Posts: 2,076
Likes: 281
From: Dyersburg TN
The big question
Ok, if you do need to torque the bolt, how? The body and frame wrap around both ends of the bolt so that the use of a regular torque wrench is not possible.
How do you do it?
How do you do it?
Racer
Joined: Jun 2006
Posts: 476
Likes: 0
From: Easton PA
Team Owner
Joined: Jul 2004
Posts: 40,370
Likes: 788
From: Redondo Beach, California
I understood exactly what you said. Seems you're not familiar with how suspension bushings work and why the trailing arm bushing depends on the clamping force of the torqued nut and bolt to function properly. The bolt is anything but a simple 'pin'.
This is a very common misconception.
This is a very common misconception.
Background: I've removed and installed trailing arm bolts in my 68. I've removed the trailing arm bolts from my 70 and re-installed trailing arms (Tom's offset trailing arms) and the trailing arm bolts in my 70. I don't have shims added however.
The forces that a bolt commonly experiences are forces in tension. That's why bolts have heads, a threaded end, and a nut. The trailing arm "bolt," operates with forces in shear. That's why I would classify a trailing arm "bolt" as really being a pivot pin. I never considered that compression forces are required to keep the bushings in place; i.e. the compression forces of the shim plates would keep the busing in place. I'll go have a look at my 70 again.
It's amazing that virtually all the acceleration forces produced by the wheels are imparted to the frame through the trailing arm "bolts." That's a lot of shear forces on this relatively small cylindrical piece of metal. Particularly when the acceleration forces are large enough to lift the front wheels off the ground.
I don't like the repro trailing arm bolts. The have a shank that is overly threaded. When you insert a repro trailing arm bolt into the frame, the threaded portion of the bolt mates up to the inner part of the frame pivot hole. It seems like the threaded part of the bolt would chew into the frame as time passes.
If you want replacement trailing arm bolts, use the bolts that fasten the differential torque bracket to the differential. They are the same bolts. (At least for my 68 they were.) I used them on my 68 and used off the shelf grade 8 bolts to fasten the differential torque bracket to the differential. They were a little long, so I used a cut off wheel to shorten them.
