rear frame rubber bumper

[John Gomez (41162)]

The mounting brackets on my '64 that were located on the rear frame kick-up section approximately 6 inches behind the upper rear shock mount on my car are missing. For whatever reason some BUBBA years ago took a cutting torch to both brackets and cut them off!

My question is:
How important are the rear rubber bumpers? Does anyone know if the steel brackets that weld to the frame and hold the rubber bumpers in place - are these steel brackets available from some source? Thanks for any replies.

John

[Donald Terry (38740)]

Re: rear frame rubber bumper

John,

Are you referring to the #4 body mount brackets? If so, yes these are available from the parts vendors. I would definitely replace these brackets if they are missing.

[Mike McCagh (14)]

Re: rear frame rubber bumper

i think you are referring to the rubber rebound /bumpers. they bolt to the frame and prevent the trailing arm from bottoming out on the frame. definetly ought to replace them. as i recall, they were available from the general and they have a metal piece imbedded/vulcanized in the rubber that allows their attachment to the frame. mike

[John Gomez (41162)]

Re: rear frame rubber bumper

Yes, it's the rubber bumper steel bracket I was referring to that holds the rubber bumper piece in place. The AIM appears to show the steel bracket as a piece that is welded to the frame and is positioned outboard to the outside of the frame kick-up itself - if I'm looking at the drawing schematic in the right way. Thanks for the replies

John

[Joe Lucia (12484)]

Re: rear frame rubber bumper

John------

The bumpers, themselves, are available from GM under the original part number of GM #3864280. However, if the frame brackets to which these bumpers attach have been removed, that's another story. These brackets were once available in SERVICE from GM. However, they were discontinued more than 20 years ago.

As a possible source for them, I would contact Vette Products of Michigan in Lake Orion, MI. They reproduce Corvette frames and, presumably, also reproduce these brackets for use on said frames. Perhaps, they will sell them seperately.

[Michael Hanson (4067)]

Re: rear frame rubber bumper

John,

There is one good possibility why the frame bumpers and brackets have been removed from your 64. If a previous owner ever installed disc brakes, there is a clearance problem between the caliper and the bracket. Many owners modified the bracket while others just removed it entirely. It was a fairly common practice years ago. Also, there were some wheel/tire clearance issues with some of the gumbo size tires that guys used back in the 60's that may also have been responsible for the removal of the brackets.

[John Gomez (41162)]

Re: rear frame rubber bumper

Michael ..
My car still has the original drum brake system. However, you bring up an excellent point with respect to the wheels that were installed on this car. A previous owner had installed American S200 wheels on my car. These wheels came with the car when I purchased it. The wheels are 8.5 inches wide. IIRC, I believe these wheels measured something on the order of 3 3/4 inches backspacing, with a -.875 offset.
I think you hit the nail on the head! .. That would seem to explain why someone went to the trouble to remove those brackets . . . I'm in the midst of doing a rear end rebuild on my car. I thought something wasn't 'right' when I saw some ragged edges of what apparently were some left over remnants of the former brackets that been cut away from the frame.
After all the years that I have owned my car I only discovered TODAY about those missing brackets!

Joe ..
I will check with Vette Products and see what they say. Thanks for the lead.

Thanks, guys, for all replies

John

[Michael Hanson (4067)]

Re: rear frame rubber bumper

Hmmmmm... Yes, I think we found the problem. I kinda knew it had to be either gumbo wheels/tires or calipers.

For 65, the frame rail was slightly modified/indented and the control arm bumper bracket was completely redesigned to move it inboard for caliper clearance. The 63-64 design bracket was well outboard of the outer edge of the frame rail and close to the wheel/tire assy. These were often removed on 63-64's. I believe the part number that Joe Lucia listed above would be for the 65 and later style bracket but I'm not sure. I don't know if the 63-64 part is being reproduced.

[Joe Lucia (12484)]

Re: rear frame rubber bumper

John and Michael-----

Yes, somehow I lost track of the fact that we were talking about a 1964 here. 1963-64 used different trailing arm, frame mounted bumper brackets and bumbers than later years with disc brakes. The bumper brackets, which unlike 65+ were the same for both sides and of GM #3832776, were discontinued in March, 1975. The bumpers, GM #3850161, were discontinued from SERVICE in October, 1982. The bumpers may be available in reproduction. For the brackets, once again, Vette Products of Michigan would be the first place I'd try.

[Paul Latour (38817)]

Pic of that Bumper

Here's a pic of what you need. Just above the caliper.

[Michael Hanson (4067)]

Re: rear frame rubber bumper

Thanks Joe. Was the 65+ bumper used through the end of C3? (the newest parts book I have is 74 and the kid down the street with a 77 asked)

[Michael Hanson (4067)]

Re: Pic of that Bumper

Paul,

Your picture would be quite a bit different than the 63-64 style bumper and bracket. The 65 and later is tucked inboard at least an inch, or more, from the original 63-64 mounting location. Would be great if someone could give us the same pic of a 63-64 from the same angle for comparrison. Thanks.

[mike cobine]

Re: Pic of that Bumper - Almost

Bare frame, but you can see the bracket out to the side.

[Joe Lucia (12484)]

Re: rear frame rubber bumper

Michael-----

The 65+ bumber was used through 1975. For 1976 through 1982, a different bumper and bracket was used. The bumper is GM #483746. I don't find that the bracket was ever available seperately from the frame, but it's possible

[Michael Hanson (4067)]

Re: rear frame rubber bumper

Thanks Joe. I'll forward the info to him.