Help sourcing part for A-arm mount replacement -

ZCAT3 · 02-22-2005, 10:54 AM

My 69S has had some minor rust repair on the passenger side front underside. Specfically, the area around where the rear of the A-arm mounts to the chassis has been cut out and a new mount welded in. This is where the the rear of the torsion bar sits and the height adjustment bolt is. In any case, the repair is structurally sound, but the mount for the A-arm is off a tad. This is causing my car to pull to the right as the wheelbase is now slightly shorter on the passenger side.

I have searched around looking for the piece but it does not appear that anyone carries this. The more common rust repair area is where the front of the torsion bars mount and that is an easy part to source.

Anyone have any ideas on this?? Thanks.

Chuck Moreland · 02-22-2005, 11:04 AM

Bill

Are you looking to replace the A arm mount, the cross member, or a section of the chassis?

Maybe this image will help

ZCAT3 · 02-22-2005, 11:08 AM

Hi Chuck - it is going to be a section of the chassis. There is that little nub that protrudes down from the body where the inner rear corner of the A-arm mounts. My guess from looking at the picture is that it is where 2/1 goes into 1/2 where 1/2 is a thread mount connected to the chassis. Make sense?

jpnovak · 02-22-2005, 11:11 AM

There is a factory part number for this part. I tried to look it up but came up empty. They are not easy to find even with the part number. The factory is the only one that I am aware of that makes that part. You may do better by cutting this section off a later car, splitting the spot welds and grafting it in place.

ZCAT3 · 02-22-2005, 11:23 AM

This is the mounting point I am referring to - the nub coming off the chassis is slightly to the rear so my wheelbase ends up a bit short.

Chuck Moreland · 02-22-2005, 11:40 AM

I was afraid that is what you meant. Not so easily replaced.

How much offset are we talking about?

A small adjustment can be made by fashioning a spacer to move the A arm forward.

ZCAT3 · 02-22-2005, 11:45 AM

They thought it was maybe 1/4 inch off. The problem is that by the time it reaches the end of the hub it is about 3/4 inch off.

Chuck Moreland · 02-22-2005, 11:59 AM

Sounds like it is off width-wise, not fore-aft.

Some compensation can be made at the front mount (pointed at by 13 above). Move the mounting holes sideways a bit to move the front of the A arm towards the center of the car. Best way to do this is to fill the old holes with weld, then redrill.

The rear mount also has a small amount of lateral adjustment (maybe 1/16 -3/16 inch). Be sure to max that out.

These compensations are a LOT easier than replacing that section and should work fine for a small correction.

Was the front of the pan also replaced? If yes, I wonder if the real problem is the front pan is not centered properly. This would scue (sp?) both A arms, one forward - one backwards, resulting in measurably different wheel base.

jpnovak · 02-22-2005, 12:03 PM

I agree with Chuck. It sounds like the a-arm mounting points are twisted.

btw, that mount is not easy to replace. The threaded insert is welded to another panel above the small protrusion. dtw replaced that section on his 72. He used a cut-out from another car.

dtw · 12:27 PM

There were maybe one or two of these left in the factory parts channels last year when I talked to Restoration Design about this item. The RD guy was trying to source a pair to make his own reproductions, since the factory appears to be discontinuing the part. Tim Walsh had a couple of 'em though - try asking him. Due to someone stuffing my pan drainage routes with undercoating, my entire tub rusted out around this mount. It was a major pain in the ass to replace, and I used a rather large cutout from a donor tub to do it.

Bear in mind that the mount is a steel tube that goes all the way up to the rearmost tank support and anchors there - so replacement is a major surgery. However - maybe you can just drill out the welds on yours, position correctly, and then re-weld.

I took a suspension mounting crossbar, checked it against another tub to verify trueness, and mounted it to the tub I was repairing in order to locate the correct position of the mount. Worked great - Three of my front suspension mounting points were replaced in my front end surgery and it took an alignment afterwards with no complaints.

ZCAT3 · 02-22-2005, 12:50 PM

Thanks for the input guys. I just spoke to Chuck on the phone as he is local to me and I think I am going to try his suggestion to start. Basically I will try to fudge it a bit to see if I can move the mouting holes on the A-arm a bit to get things to line up correctly.

I do remember that after I replaced the front strut inserts and rotors that the torsion bar cap slipped of the bar on the passenger side (with quite a thunk I might add) the first time I set the car back down. This may indicate that the mount is a little off to the rear thus allowing some play in the torsion tube that should not be there.

ZCAT3 · 02-22-2005, 12:51 PM

By the way I do have a call into Restoration Designs.