Assembling the new front crossmember

[65 wonton]

I've bolted up the 73 front cross member to my 66 frame (1 ton). Seems everyone said there'd be 1 hole to drill and 1 hole to oblong on each side. Not on mine. 7 holes fit perfect (4 to the side and 3 to the bottom of the frame).

1. So when I bolt up the lower control arm, at the frame side, do I just center it? Or is this an adjustment that the alignment person will work with when its on the rack?

2. Specs call for 8 ft-lbs on the 1/4" bolts that hold the upper ball joint to the control arm. Seems awful light. But that is in the Torque tables also. Any other opinions?

3. Rear spring stacks appear to be symetrical. Is there a front or rear, left or right? Leafs on the 1 ton not trailing arms.

4. The front control arm bushing (well really there aren't any) thread onto the mounting shaft and into the control arm, at the same time. Is there a certain way to do this or are they just seated and bottomed out? Are there torque specs on these? Seemed like they were on very tight when disassembled.

Thanks for any input.

Dave, yup pics are being saved for the official thread to come.

[Captainfab]

I've done several front crossmember swaps using '73 and up C10 crossmembers on '63-'66 C10's and C20's, and have only had to drill 1 hole on each side and elongate 1 hole on each side. Not knowing whether you are installing a C10, C20 or C30 front crossmember, it is possible there could be a difference there.

1) As for the locating of the LCA, there is a shallow hole drilled into the shaft, that registers on the rivet that mounts the saddle to the crossmember.

2) Yes 8 ft lbs does seem rather light. I just looked it up and what I read does say 8 ft lbs for a grade 5, 1/4-20 and 12 ft lbs for a grade 8, 1/4-20 bolt.

3) I'm not sure on the C30 rear springs if they are symetrical or not. I've never had mine out. I would have to measure them tomorrow.

4) I don't have a good answer for this as I have only replaced those 1 time, quite a few years ago. I do remember it was a big PITA.

[65 wonton]

Hey Captain, thanks for weighing in.

My original frame is a '66 1 ton. The crossmember a '73 3/4-1 ton. I spoke too soon. 6 of the 7 holes fit perfect. The 7th had to be "oblonged". Its on and torqued and fits fine. I don't know why I didn't have to drill the other hole as others have, maybe the difference between 1/2 and 3/4-1 ton.

I saw the dimple in the LCA mounting shaft and thought about the rivit being a register. When I looked at the saddles, the rivit didn't seem to protrude enough to engauge the shaft. I'll have to examing that closer.

On the 3/4-1 ton UCA and LCA "bushings, the end caps thread on. Right or wrong, what I did was try to center the shaft within the control arm mounting ears. I then threaded the end caps onto the shaft until the threads started to enguage the control arm ears. that way everything appears to be evenly mounted. The control arms move smoothly.

Dave.

[Captainfab]

Yes the control arm shaft bushings thread onto the shafts. Where they pass thru the control arms, there are very shallow 'threads' that must be engaged also.

[65 wonton]

Just to confirm. The saddle rivits (front) do register the control arm mounting shaft. Seems it would be obvious. but the amount of the rivit that protrudes can easily be miss by just running a finger over it to determine whether or not it registers, but when one mates the shaft up it is obvious.

Thanks,

Dave.