I just finished installing subframe bushings in a well-worn 250SL. Fortunately, this was done with the engine out. This has caused me all kinds of difficulty in the past, but this time I tried a different technique, which worked very well.
Start with the car jacked up and supported with stands under the frame.
1. Install the new mounts on the frame without the covers, using all four bolts. Repeat for other side.
2. Position the subframe under the car using a suitable dolly. Make sure that any steering components are positioned so they can be reconnected with the subframe installed. Tie them back with wire to keep them out of the way.
3. Using straps looped through the opening between the subframe and the control arm, use an engine hoist to lift the subframe up and against the new mounts. Have a helper lift the anti-sway bar to keep the subframe assembly level and help position the assembly.
4. Secure anti-sway bar to the frame. Secure the subframe to the mounts using the large bolts and washers.
5. Keeping lifting pressure on the subframe at all times, replace the hoist with a floor jack. Remove the four bolts. Place the cover over the mount, and reinstall the four bolts. Repeat for other side.
6. Raise the car and move the jack stands under the lower control arms, and remove the jack.
Using this technique, I had none of the problems aligning the mounts to the frame that have plagued me in the past. I found that lifting with the hoist rather than a jack made it much easier to position the subframe.
Cheers,
CT
