W201 subrame frozen to body?
 

I'm trying to drop the whole rear subframe on my 1992 190E. I've loosened/removed everything necessary. Shocks, springs, brakes, driveshaft, handbrake cables, fuel line, etc...

I've loosened the 4 bolts holding the subframe to the car. All bolts came out easily. I removed all of them and now the subframe is held by a floor jack. The bushing on the rear right seems stuck to the sleeve protuding from the body of the car. I tried everything to get it out:

1- Major amounts of PB blaster
2- Lowering the jack a bit and wiggling the whole subframe. Even with no jack or no bolts, the whole thing is held on by only this one mount
3- Jamming a ball joint pickle fork between the body and the subframe. I thought this was gonna work but no dice.
4- Even jumping on the wheel hubs on the right side can't create the force needed to un-freeze the thing.

I haven't tried heat because I don't have torches. Any other suggestions? I can't cut the sleeve off and weld another one because the threads won't work anymore and a cutting tool won't fit in there...

If you already pulled the spring, put it back in and leave it to work its own force for a while. Give the PB Blaster time to work. I'm just guessing here, so take it for what it is worth.

Yeah I might try again tomorrow. Usually I get angry about frozen bolts, soak them in PB and the next day they're free to go.

Mix up some acetone and ATF at a 1:1 ratio. PB Blaster is a joke IMO. Kroil or acetone/ATF is much more effective and doesn't smell quite as bad.

if you have an impact hammer try buzzing it - I believe bodhibenz also had this issue when she wanted to pull the rear carrier frame from her W124.

I had a similar issue but forget how we dealt with it. I think we threaded the bolts back in a bit and used a 6 foot digging bar as a pry bar.

This thing is really f* stuck there! I broke my pickle fork trying to pry it out. I tried drilling holes in the bushing to separate the subframe part from the rest of the bushing, it still doesn't work. I'm contemplating cutting the mounting tube off the car and weld it back on, but then positioning it will be difficult. Every prying, hitting, twisting, the bushing absorbs it...

The rate you're going it sounds like you'll pull away the mount on the chassis.

I suggest you cut the mount away from the sub frame mount.

Normally you use a hydraulic press =>

http://www.peachparts.com/shopforum/3254862-post320.html

I understand your frustration - attempting this with everything fitted to the car would make things 100 times more difficult.

Try not to damage the chassis / body. That's harder to repair than the sub frame.

Rather than damage the body, I'd cut the sub frame away since it is replaceable. And, I'd tend to leave a few bolts threaded in a couple of turns so the sub doesn't suddenly fall when it breaks loose.

Saw this one. He recommends a wiggle: Rear Subframe bushes 210 HELP!!! - Mercedes-Benz Owners' Forums

I would also consider heat before getting drastic. Portable torches are dirt cheap at the hardware store.

I like the ATF/Acetone method. It works, but is somewhat slow. For a more aggressive method (quicker acting), you could try a little D2 or Kero on the metal to rubber location(s). It creeps and helps dissolve/loosen the metal/rust to rubber bond. Learned this trick years ago when busting tractor tires in the field. Gasoline really works well BUT its very tricky & very aggressive, not to mention very flammable. Ditto for volatile solvents.

Oh yeah, almost forgot - Fire Safety First! Heat &/or flame and solvents do not mix!!

Any luck with this? It seems I have the same problem. If a night of soaking in Kroil doesn't do it, I will resort to the saw.

A little heat. That's about it. I used a propane torch to heat the center hub. The rubber burned and smoked, but it's too smoky to stay lit. Hose nearby just in case. Once it was hot, a whack or two with a hammer was all it took.

Fantastic

This wasn't my thread, but I happened to have the same problem. To finish this up, I thought it might be helpful to post some photos.

The first photo shows the offending mount. All I did was hit the center cup with a plumbers torch. From time to time, the rubber would catch, but the rubber self extinguishes if the torch is removed. Keep a hose handy, and remove the fuel tank for safety. A fan to keep the smoke out of your face is also helpful. Once the center was nice and hot, a few whacks with a 3lb hammer freed it up.

The second photo shows the inside of the cup, plenty of corrosion. The cup seems to be made out of aluminum.

The next photo shows the reason I was doing this...northeastern salt damage is a car-killer. And the final photo is the rust-free replacement from sunny California. I want to send my cars to CA for vacation.