Body bushing dimensions

[john87442]

Ok so as I’m welding new body mount washers in to fix the rusty frame holes I broke out the factory 1987 service manual to look up the hole location and dimensions to verify what I’m doing. First thing is converting the mm measurements into inches and then I noticed the book list the location of number 1,2,3 and seven but nothing in between or ways to cross check your holes for square. Any ideas as to what I’m missing?

 

[57 Handyman]

John, when I swapped an 84 frame under my 87 El Camino, I was very fortunate that only the front passenger side body mount bushing hole was damaged. I attributed the rust damage due to the proximity of the drain of the AC/heater box which was right above. If not mistaken, I believe this location was #2. For my body style, there were a total of 7 positions along each side of the frame rail. It may very well be possible that GM used only 4 points for you sedan. The best way to check is get under and verify.

As for your reference to "ways to cross check these holes for square," I don't quite understand what exactly you are driving at. Are you referring to whether these body mount locations on either the frame and/or body are where they should be? If that is what you want to know, my suggestion is to have your vehicle inspected at a frame/body shop. Have them do an inspection by measuring specific points outlined in the field service manual. They do this inspection regularly when vehicles are in accidents. Do this BEFORE you do anything to your vehicle. If it is not straight, they can pull and align everything according to the factory measurements.

Hope this helps.

 

[john87442]

There is 7 bushing mounts also for my frame but what I’m referring to is that I have to cut out the rusted part which will cause the hole to be oversized and then fit my body washer with the inch and a half hole in and weld it. I would like to center the hole of the body washer so it is correct to the factory dimensions and everything will line up. The cross check comes in by measuring front to back and side to side but also should line up from corner to corner. I have the factory manual for my year 442 but all of the measurements are not listed. Thanks for the help, I probably didn’t explain that very clearly.

 

[WanaBa442]

I think what you're looking for is where to put the hole, in the hole you made.
I think you'd need to find someone with a good frame to measure c/c of existing holes from side to side, and then from a good existing hole to the one(s) you're replacing on the side rails of the frame.
Someone here must have a frame off and can help you out...
Found this but not sure its what you need:

The other option if you have the body off the frame is measure the hole locations in the body shell and make them match..

 

[john87442]

Thanks I do have this image also. And that’s a good idea about measuring where the location is on the body. I did do that for the ones in line of each other unfortunately the bracing is in the way to get the other measurements.

 

[RegalRegal]

Also keep in mind the caged nuts that the bolts thread into have some play, so it does not have to be perfect.

 

[john87442]

Very true and I did think about that but the over analyzing in me pops up all the time.

 

[57 Handyman]

John, here's another approach.

1. Find/identify a few reference points on the driver side of the frame rail near the body mount hole;
2. Make a paper pattern of that area which includes the driver's side body mount hole;
3. Flip over your paper pattern, then locate and align the pattern with the same reference points on the passenger's side of the frame rail;
4. With the pattern positioned and aligned with the reference points, that should be the location for your passenger body mount.

You can also use the measurements in the diagram to verify the closeness. Also, what RegalRegal says is correct that the caged nut allows some leeway.