Body mounts

[Clone TIE Pilot]

The problem is that even rust free cars can have issues with body mounts and you won't find the issues until you start doing the disassembly especially since the cage nuts are held in place with very thin metal.

That is what happened with my car. All my body bolts came out ok, but the frame mount on passenger side #2 was rusted out. Had to carefully jack that corner of the body off the frame to weld in a frame mount repair washer. It seems it is very common for the passenger side #2 to be rusted out because the HVAC drain pours water there. Also the stock body mount bushings are not well designed, they have a thin metal reinforcing insert that can completely rust out leaving the bushing hollow and often rusting the frame mount too though direct contact.

 

[pontiacgp]

That is what happened with my car. All my body bolts came out ok, but the frame mount on passenger side #2 was rusted out. Had to carefully jack that corner of the body off the frame to weld in a frame mount repair washer. It seems it is very common for the passenger side #2 to be rusted out because the HVAC drain pours water there. Also the stock body mount bushings are not well designed, they have a thin metal reinforcing insert that can completely rust out leaving the bushing hollow and often rusting the frame mount too though direct contact.

nothing on these cars were designed to last 30 years..

 

[ed1948]

Serious question re: body mounts. I don't have any practical experience with rubber body bushings.
Is there actually a measurement standard to determine if the mounts have compressed past their limit? It seems that everyone assumes, because the chassis is 30 years old, that automatically all rubber components are worn out. It is possible that the vehicle may have been kept in an environment that was 'friendly' to rubber. I have only one body mount that has a rusty backing washer and none appear to show any cracking.
ps. I am planning to redo my 30 y.o. mounts just because....

The only clue I have of possibly worn rad support bushings is a bit of front fender/header panel flexing when crossing road bumps.

 

[403Olds]

When I did mine, one mount was completely missing. After replacing all the bushings, the fender gaps are all equal, and the squeaks are gone. Of course that was with 190k miles.

 

[pontiacgp]

Rubber like everything else has a shelf life. As an example you are not supposed to install new tires if they are 6 years old or older

http://www.vbri.com/files/articles/elastomershelflife.pdf

 

[Clone TIE Pilot]

Serious question re: body mounts. I don't have any practical experience with rubber body bushings.
Is there actually a measurement standard to determine if the mounts have compressed past their limit? It seems that everyone assumes, because the chassis is 30 years old, that automatically all rubber components are worn out. It is possible that the vehicle may have been kept in an environment that was 'friendly' to rubber. I have only one body mount that has a rusty backing washer and none appear to show any cracking.
ps. I am planning to redo my 30 y.o. mounts just because....

The only clue I have of possibly worn rad support bushings is a bit of front fender/header panel flexing when crossing road bumps.

A body bushing can look completely fine on the outside while being totally rotted on the inside. Only way to know is pull the bushing and inspect it.

 

[jiho]

A good idea I read on here is to drill a 1/4" hole above the cage nut so you can soak the cage nut with penetrating oil.

That really is a good idea. You can get plastic snap-in plugs, too.

 

[mobileaudio25]

I had to pay to get my rear 4 mounts done. He had to go through the truck. I went with rubber replacements was that a good idea or are poly better? I still need to do the front ones are they a lot easier to do? Are there any threads on how to?

 

[Texas82GP]

There are lots of threads on body mounts. I prefer a Google search over the forum's search engine. Try "g body forum body mount". Material choice is a preference deal. Urethane will last longer but is often said to be stiffer.

 

[mobileaudio25]

There are lots of threads on body mounts. I prefer a Google search over the forum's search engine. Try "g body forum body mount". Material choice is a preference deal. Urethane will last longer but is often said to be stiffer.

I purchased new rubber body mounts about 2 years ago. I have the rear 4 installed not the ones upfront. The car is garage kept and only driven around 2-300 miles a year what type of life expectancy do you think I could get out of the rubber body mounts?