AIM Identification for J56 support bracket and caliper

[Mark F.]

Re: AIM Identification for J56 support bracket and caliper

Robert' No C1,s that I am aware of were ever built with disc brakes I quoted the HD numbers off lay out print # L-91771 I believe they are plant assembly numbers not readily available. First drawn 8-4-64 and updated with revisions thru 1974. The print does list all bolts with specs and part numbers including torque specs. My problem is trying to figure out what bolts you are interested in.

Perhaps you could just post the drawing you are referencing ?

[Robert K.]

Re: AIM Identification for J56 support bracket and caliper

David,

Yes, I agree with you re: C1's re: disc brakes...........

I wish I could provide you with a more definite response however, I do not have any drawings to show which bolts.... I'll try this way.......:
1) bolts that attach the calipers to the front suspension (NOT the bolts that hold the caliper halves together)
2) bolts that attach the support brackets (on the front) to the suspension (there are part of the F41 option suspension hardware.......
3) bolts that attach the larger diameter torsion bar to the front suspension (these are part of the F41 option suspension hardware......
4) other attachment bolts (I can't explain which ones because of a lack of a drawing) which make up the F41 Option. I know there are a number of others both on the front of the car and the rear of the car)......

Thank you David for any help you can provide....... (if you could just post (as Mark notes) or send me the drawing, that would be great too!!

[Joe L.]

Re: AIM Identification for J56 support bracket and caliper

David,

Yes, I agree with you re: C1's re: disc brakes...........

I wish I could provide you with a more definite response however, I do not have any drawings to show which bolts.... I'll try this way.......:
1) bolts that attach the calipers to the front suspension (NOT the bolts that hold the caliper halves together)
2) bolts that attach the support brackets (on the front) to the suspension (there are part of the F41 option suspension hardware.......
3) bolts that attach the larger diameter torsion bar to the front suspension (these are part of the F41 option suspension hardware......
4) other attachment bolts (I can't explain which ones because of a lack of a drawing) which make up the F41 Option. I know there are a number of others both on the front of the car and the rear of the car)......

Thank you David for any help you can provide....... (if you could just post (as Mark notes) or send me the drawing, that would be great too!!

Robert-------


1) The front caliper attaching bolts for standard brakes are 7/16-20 X 1-1/4". Originally, these were GM #186645 but that part number was never available in SERVICE. These are GM 300M grade bolts (SAE grade 8). With J-56 the FORWARD of these bolts was replaced with a bolt of 2-1/4" length to accommodate the thickness of the caliper support bracket. The rear bolt was the same as standard brakes. A lockwasher was used with both bolts;

2) The bolts that attach the steering arm, spindle, and caliper bracket are 7/16-20 X 2-1/4". When the caliper support brackets are added for J-56, these bolts are 1" longer than those used for cars with standard brakes and are, thus, 3-1/4". These bolts are also GM 300M material grade. They are retained by a self locking nut, probably of GM #9422300. I believe a flat washer was used in conjunction with these nuts.

3) Bolts that retain the sway bar retainers to both the frame and to the lower control arms are exactly the same as non F-41;

4) I know of no other bolt differences for standard versus F-41 front suspension.

[Leif A.]

Re: AIM Identification for J56 support bracket and caliper

Robert-------


1) The front caliper attaching bolts for standard brakes are 7/16-20 X 1-1/4". Originally, these were GM #186645 but that part number was never available in SERVICE. These are GM 300M grade bolts (SAE grade 8). With J-56 the FORWARD of these bolts was replaced with a bolt of 2-1/4" length to accommodate the thickness of the caliper support bracket. The rear bolt was the same as standard brakes. A lockwasher was used with both bolts;

2) The bolts that attach the steering arm, spindle, and caliper bracket are 7/16-20 X 2-1/4". When the caliper support brackets are added for J-56, these bolts are 1" longer than those used for cars with standard brakes and are, thus, 3-1/4". These bolts are also GM 300M material grade. They are retained by a self locking nut, probably of GM #9422300. I believe a flat washer was used in conjunction with these nuts.

3) Bolts that retain the sway bar retainers to both the frame and to the lower control arms are exactly the same as non F-41;

4) I know of no other bolt differences for standard versus F-41 front suspension.

Great info, as always, Joe. There were no flat washers used at this location...just the special locking nuts.

[Robert K.]

Re: AIM Identification for J56 support bracket and caliper

Hi Joe,

Thank you for providing this information - it's detailed and complete. I sincerely appreciate all the time it takes for you to research this and gather it.

Take care and have a good evening.......

[Robert K.]

Re: AIM Identification for J56 support bracket and caliper

Leif,

Thank you also for the clarifying information......