1968 Buick Riviera Body Bushing Removal/Installation

[pocanokee]

While replacing the body bushings in my base model 1968 Buick Riviera, I have run into an aggravating problem with a particular bushing.  In the frame arch above the passenger's side wheel well the bolt has broken loose, but corrosion will not allow me to turn the nut further and remove the bolt.  The cage nut configuration fairly well inhibits my ability to get a wrench on the top of the bolt, and copious amounts of Liquid Wrench and WD-40 have done nothing to free up the seized nut.  There is insufficient room above the nut to cut the bolt.  I really don't want to cut an access hole through the passenger compartment to reach the head of the bolt, but I also don't want to leave it as is and have an annoying rattle in the back of the car.  Any viable solutions or suggestions for this situation would be greatly appreciated.  Thanks to all who respond.  Paul

[JZRIV]

No easy solution here without operating. Once the cage nut spins in the cage, you must access it. I've cut an opening through the side of support directly in front of the cage, then broke/cut the the cage loose to get a wrench on the the square nut. The cage is spotwelded to housing. There are variations once you have access. On one occasion I was able to jam a flat screw driver in between nut and side of cage to keep it from spinning, then heat the nut red hot and it comes right off.

I wouldn't attempt to access it from top. I think that would be an effort in futility.     

For anyone doing this in future, soak the cage nuts often for a couple months prior to trying to loosen bolt. Dry climate cars are wonderful when it comes to these mounts! 

Edited August 4, 2022 by JZRIV (see edit history)

[60FlatTop]

I had to trim out an access hole for the caged nut adjacent to the rear wheelhouse on my '64 Riviera. It is not a big deal. You can flush weld a patch over it and you will be the only one who knows.

 

And, if some self appointed judge finds a flaw in your car sometime in the future you can always say "Oh, yeah" and roll back the carpet while you say "I bet you never even thought to look here!"
 

[pocanokee]

Thanks Jason and Bernie.  Tried the screwdriver approach, but still couldn't keep it from spinning.  I'll try cutting an access hole from underneath and torch the nut once I get a good grip on the head of the bolt.

[NC1968Riviera]

13 hours ago, pocanokee said:

Thanks Jason and Bernie.  Tried the screwdriver approach, but still couldn't keep it from spinning.  I'll try cutting an access hole from underneath and torch the nut once I get a good grip on the head of the bolt.

Keep us posted on your progress.