62 Cutlass Convert

Had this posted in Chassis, lots of views but no answer. Thought this might be the right forum? Gotta be someone who has done this and knows!

I am going through the front suspension of my car and need to set up the control arms. The service manual says upper arms are centered on the pivot shaft and the lower arms are positioned on their shaft using a factory tool, a spacer between the control arm and the pivot shaft threaded boss in the subframe. Size of the spacer is not given, only the tool number. All the spacings front to back for uppers and lowers were different on the arms prior to disassembly. Car and subframe do not appear to be damaged or bent.
The procedure for the lower control arm spacer is to use it on one side of the arm, tighten the bushing and then tighten the other bushing. So I am not clear if the bottom control arm has equal spacing front and back or not since I do not know the size of the spacer.
Service manual notes alignment is achieved through typical spacers on the upper control arm shaft. No mention of movement of the upper or lower control arm front to back. Spacing of the control arms can only be changed by removing both bushings, repositioning the control arm, and re-threading the bushings.
Questions are:
1. ***Is the spacing for the lower control arm to the pivot shaft boss equal for front and rear, or…?
2. *** Is it acceptable and can I achieve more positive Caster with movement of the upper control arm. Purpose would be to firm up steering and road feel from the typical 60’s feel. I have manual steering.

62 Cutlass Convert

Help, any steel control arm bushing alignment experts out there?

joe_padavano

The arm wants to be centered on the shaft front-to-back. These metal bushings are actually threaded nuts that screw on the threads as the suspension arms move. If you bias them too far one way or the other, you will either run out of thread engagement or bottom the bushing. Either way, it will be bad. To get the positive camber you seek, you'd need to bias the lower arm forward. I doubt you'll be able to get sufficient travel to make a difference.

You may not be aware that Fatman Fabrications sells a complete bolt-in front crossmember for these cars with a modern front suspension and rack and pinion steering. It's not cheap (starts at about $3K) but it makes a big difference in the handling.

62 Cutlass Convert

Good point on running out of room with the bushings/nuts. Thanks for the confirmation of center location for the lower control arm. I'll pay attention to the room afforded by the bushings and I think I'll move the lower arm forward a little and the upper arm back a little as a starting point for the alignment shop. Maybe only gain a degree or so but might help a little. I'll do some trial and error to see how much room I have on the bushing so as to not get into trouble.

I have seen one of your earlier posts about Fatman but it's too much money to put into the car at this point.

Thanks again for the info. This is the red convertible that was a partner to your San Jose wagon in the barn.

62 Cutlass Convert

Joe or anyone, I know there are drivers on these cars out there. What kind of Positive Caster is the alignment shop able to get? Can they get out to 4-6degrees of Positive.