caster shim installation issues (1 Viewer)

[piecemeal]

A couple months back I started a thread about my 74 walkin all over the road. I took everybody's advice and purchased caster shims, a new steering stabilizer, new U-bolts and new spring pins. I already had HFS barbell shackles ( 2" lift ones ) installed from PO and bought 4 deg caster shims. Well I got the U-bolts off on the driver's side rear and spring pin, installed new spring pin win a taller head, set the caster shim with the fat side towards the front of the truck and when I lowered the axle, I couldn't get the axle to slide onto the spring pin. So I went to other side, did the same thing and was able to get the pin to drop into the axle with the shim in place. Unfortunately, I couldn't get the driver's side rear to drop in. So I disconnected the left rear shock thinking it was binding the whole process up somehow. However, even if I pull the axle forward with all my might, I still can't get the pin to drop in the slot in the axle. I was leary to do this whole process being a newb, but figured if I did a drum brake overhaul for the first time I could do this. I'm at a loss. Anybody have any suggestions?? And is the fat part of the caster supposed to face forward??

 

[numby]

... I got the U-bolts off on the driver's side rear and spring pin... I couldn't get the driver's side rear to drop in. So I disconnected the left rear shock thinking it was binding the whole process up somehow.

I'm not familiar with your original problem but caster shims generally get installed on the FRONT axle. If you can't get the rear axle re-centered under the springs then disconnect everything (driveshaft, shocks, brake cables, etc) to prevent any hang-ups.

 

[VTGreg]

Funny, I went through this yesterday on the front axle of my '78. I wound up tightening the u-bolts in a manner that helped walk the pin into place, i.e., snugged the rear nuts to push the axle forward enough to align the pin. Having the weight off the entire front/rear of the truck vs only jacking up the corner you're working on helps too. And loosen all the u-bolts on the axle to let it move as you work. I BELIEVE the fat part of the shim points to the shackles on each end, but I haven't done the rear axle yet so I'm not totally sure.

 

[piecemeal]

can anyone verify that the fat part of the caster shim faces towards the extended shackles on both the front and rear?? The SOA diagram shows it this way but someone told me that on the rear axle the fat part faces towards the front of the vehicle (with the extended shackle being installed at the very rear of the vehicle. Is this true?? I'm confused. Maybe that's my whole problem....

 

[cmiller114]

If your original problem was twitchy steering, you shouldn't do any thing to the rear axle, only the front. The shims to restore caster on the front end are installed with the fat part forward towards the front of the truck. Installing shims in the rear will change your pinion angle....If your not getting vibration out of the rear, leave it alone.

 

[piecemeal]

thanks cmiller. I'll just keep the new spring pins in and put the new U-bolts on minus the caster shims for the rear and put shims on the front only.