Rear Shock Mount Repair.

[Big_John]

They shouldn't let some people use impact wrenches.

One of those people changed the leaf springs on my car when the previous owner had it. Along with screwing up the shackles and leaving the old, rotted, rubber bushings in place, they also cross threaded and stripped the threads on the left lower shock mount.

When I replaced the springs, I didn't realize the damage until I got it back together. I used a longer nut (one of the old u-bolt nuts) and that helped, but it wasn't really secure. It held together though... keeping the shock on, but I couldn't really tighten the nut.

So... I looked around for a lower spring bracket. Come to find out, the bracket is the same as the B and E bodies, so I guess that makes them made out of gold... Anytime I found one for a decent price, it was the right side and, of course, I needed the left.

Kept putting it off... Said I was going to fix it "this winter" a couple times.

So... I did a little research and come to find out, Dorman makes a replacement shock mount and it's $6. This appealed to my cheap C body nature, so I ordered one.

https://smile.amazon.com/Dorman-HEL...1&keywords=dorman+31001&qid=1587327543&sr=8-1

The diameter where the shock slides on is just a RCH smaller, but we're talking a rubber shock mount that will easily squeeze down on it. Thread diameter is smaller too, but that won't affect anything. Everything else looks good.

So, gotta remove the old stud. It looks like it's pressed in and possibly swedged over. I've never seen one come out, so we can figure it's not coming out easy.

First thing was to center punch a starting spot and then drill out the stud. Strated with a 1/4 drill and worked up to 1/2". The hole looks a little high, but it's really centered on the stud. The factory swedging is a bit offset though.

Just had to drill in a little over 1/4" deep.

Now, with a hole in it, I used one of my favorite implements of destruction, a Sawzall to cut the stud off. Drilling the hole first made this job a lot easier because the stud is hollow.

Cleaned it up with my trusty die grinder.

Done! An hour's time and $6...

 

[Snotty]

Good work!!

 

[bluefury361]

I try to avoid using a impact on older cars. Most of those fasteners have been in place for many years and the sudden action of a impact can cause damage like this.
The key to working on our older cars is patience. It's not to be treated like "flat rate". Penetrating fluids, hand wrench's and finesse will usually result in a satisfying job.

 

[57fury440]

I agree. Nice job.

 

[fury fan]

I try to avoid using a impact on older cars. Most of those fasteners have been in place for many years and the sudden action of a impact can cause damage like this.
The key to working on our older cars is patience. It's not to be treated like "flat rate". Penetrating fluids, hand wrench's and finesse will usually result in a satisfying job.

Part of his damage was cross-threading, so that was an assembly issue.
Penetrating oil and patience are useful, yes. But I've actually found that an impact wrench has helped me remove rusted nuts on bigger/graded bolts, as the shock/speed breaks the rust-fusion. I wouldn't do that on a crankshaft bolt, or exhaust manifold stud, but on bolts like these I'd try an impact if they didn't come loose easily with a wrench/ratchet. One's MMV, of course, but IMO putting sustained torque on a rust-fused bolt is asking to snap it.


And for those not yet aware -
B-body leafspring bushigns for B-bodies will fit our cars perfectly. Knocking out the shackle pins and drilling them for 9/16" bolts is a nice upgrade, too. I did this on one car when I 'rebuilt' the leafsprings and those bushigns lasted for about 15 years before they started squeaking. I bought new ones (the cost is only about $30) and when I removed the old ones they were still serviceable, a cleanup and re-grease would've been sufficient for some more years. (Some B-body strutrod bushings fit our cars also.)

 

[live4theking]

Nice job.

 

[stubs300]

So... I looked around for a lower spring bracket. Come to find out, the bracket is the same as the B and E bodies, so I guess that makes them made out of gold....

What about the "A" bodies brackets?? It would seem to me as basic as these brackets are, I would think they'd interchange between all models? Kinda like a voltage regulator, or lug nuts.

 

[Big_John]

What about the "A" bodies brackets?? It would seem to me as basic as these brackets are, I would think they'd interchange between all models? Kinda like a voltage regulator, or lug nuts.

A body brackets for a 7 1/4 are smaller. The axle tube being smaller in diameter uses a smaller uses a smaller u-bolt, so the spacing on the bracket for the u-bolts is smaller. I could find those cheap all day long.

BTW, A body lug nuts are 7/16.

Generally speaking, B, E, and C (with no insulator) bodies use the same bracket. Probably an A body with a 8 3/4 uses the same bracket.

 

[commando1]

Great information, John. It's the little stuff like this that makes for a good forum.

 

[stubs300]

A body brackets for a 7 1/4 are smaller. The axle tube being smaller in diameter uses a smaller uses a smaller u-bolt, so the spacing on the bracket for the u-bolts is smaller. I could find those cheap all day long.

BTW, A body lug nuts are 7/16.

Generally speaking, B, E, and C (with no insulator) bodies use the same bracket. Probably an A body with a 8 3/4 uses the same bracket.

That thought totally slipped my mind, makes sense!

 

[Anthony 71 Paisley]

I know this thread is over a year old . Hope you don't mind me picking your brain . I am in the market for the isolators for the C body shock plate, but now lokjing at this thread I'm wondering if i could just switch to non-insulated and what would be all involved with that ?

 

[bluefury361]

I know this thread is over a year old . Hope you don't mind me picking your brain . I am in the market for the isolators for the C body shock plate, but now lokjing at this thread I'm wondering if i could just switch to non-insulated and what would be all involved with that ?

HD canvas impregnated with anti seize works good.

 

[Anthony 71 Paisley]

HD canvas impregnated with anti seize works good.

As in lose the factory isolator in put canvas with slathered on anti seize on it ? The insulators look pretty thick is there any issue with the canvases being so thin?

 

[Anthony 71 Paisley]

HD canvas impregnated with anti seize works good.

As in lose the factory isolator in put canvas with slathered on anti seize on it ? The insulators look pretty thick is there any issue with the canvas being so thin?

 

[fury fan]

I've not disassembled one of those on a C-body (I did on a Cordoba and an Aspen 25 years ago).
On both those cars the spring perch welded on the axle tube has a large hole (maybe 1" dia?) to pilot it on the upper isolator bracket. A non-iso system has a smaller hole that pilots on the leafspring centerbolt (1/2" dia?).
So you might need a piloting spacer, then possibly a shorter rear shock as you'll be losing and inch or 2 of height in the stack.