Tips for removing siezed subframe bolt?
 

I am attempting to remove the large bolts that run through the middle of the subframe mounts on my 123. Totally seized. I have been applying PB buster and propane torch for two days, but no help yet. The rubber just seems to take all my turning force- I can turn the bolt 90 degrees, but it comes right back. I am applying a lot of force, the 18 inch breaker bar is visibly bending.

Should I get a longer breaker bar?

More oil?

Other tricks?

I had the same problem on one side. What worked for me was a pneumatic wrench - not a ratchet type, but the big ol' garage type. Even with that it took maybe 10 minutes of going back and forth to get it to start moving. I was ready to get a hacksaw blade or keyhole saw and cut the rubber loose when it finally started to move. -

surfblau,

You don't need a bigger wrench, you need a bigger torch. Take it someplace where they have an acetelyene torch. If you light up the rubber, let it burn and replace it.

P E H

When after everything has been tried, and the head snaps off the end of the bolt,,,, you have to access the nut it screws into,,, usually not a pretty job.:eek: We occasionally have success heating the head of the bolt red hot, but let it go to black before you try turning it out. Sometimes that breaks the seal between the bolt and nut.

For improving leverage on braker bar or ratchet..... nothing works as well as lead pipe that extends the handle say, adding 2-3 feet.

try soaking it in coke or pepsi, an acid bath can work. turn it as
far as you can and let it sit for a while. poor liquid nitrogen on the
rubber and hit it hard. put a air tool on it and vibrate it apart.
turn it backwards to free it. cut off the bolt head, pry off the rubber and use vice grips on the bolt. mapp gas is hotter
than propane.

Surfblaw,

The bolt is fused (solid start diffusion) to the steel core of the rubber part. Its hard to get the heat all the way thru the bolt with out burning the rubber. So just burn the rubber away and then you can burn the steelcore off the bolt.

That's what I had to do to the front suspension in my '80 300SD. The dealer wanted $700 to fix it. I did it myself it in a couple of hours and 2 new rubber bushings. Yes, it makes a lot of smoke in the garage, but it dissapates quickly.

P E H

I think all people should have a CO2 fire extinguisher in their garage.