So I finally did the flex disks on the Queen Mary, our Black/Black 1989 560 SEL.

Since I am also doing the engine mounts, I decided to replace the rear mount as I finished the flex disk job. I followed the manual pretty much to the tee - and in there it tells you not to tighten down the final "adjustment bolts" for the rear (transmission) engine mount until you have run the engine for a couple of minutes.

OK the car is up on jacks, so I put it in Park, and start the engine. And this racket is all over the place, but then disappears. I go "what was THAT!!???", but since it went away, did not give it much thought. I shut everything down and then tightened down the bolts.

OK, I'll do the main (front) engine mounts next time, I'm ready to go home, I told myself, and lowered the car. I then started it again, to drive home, the the racket started again. I put it in drive, the racket went away, but now I was concerned. So I shut it down, opened the hood, and started searching. Did I bust the exhaust by letting it hang too low? What was going on???

Then I realized the racket was coming from the front of the engine. Oh my god, look at the fan shroud and the fan! The fan was so low it was striking the bottom of the fan shroud!!

It took me just one second to figure out what was going on. The new engine mount in the rear had pivoted the engine, sitting on the old, collapsed mounts in the front, so far upward in the back and downward in the front that the fan was beginning to hit the shroud! The entire engine mounting profile had changed! When I put it in gear, the strain on the drive train held by the brakes would change the angle of the whole assembly enough for the fan to clear the shroud again.

I locked the car up back in the garage and walked home...

Lesson is: Wise man say when do rear engine mount, do all, otherwise there shall be bad racket!!!

__________________
Henry Bofinger
1989 560 SEL (black/black)
2001 Audi TT Roadster (silver/grey)

Yep. My 6-cylinder SE has vertical adjustments on the fan shroud, where the top clips attach. As my front mounts sag (pretty routinely) I adjust the shroud a bit to keep the fan centered. You might be able to do that to make it driveable until you can replace the front mounts.
Remember of course that the angle change may put additional angular load on the front flex disc, and maybe even change the middle u-joint working angle a bit. So, might be a good idea to install the front mounts pretty soon.

DG

Just did the front mounts. What a mess!!! There are no torque specifications for tightening the mounts to the frame, just from the mounts to the engine. I can figure out why - at times all I could work with was a regular 6 mm allen key! That is with the engine lifted so high that (a) I had to remove the top radiator hose for the fan shroud to clear, and (b) make sure I did not break off the auto tran dipstick tube! It took me a good five hours!

But the old ones were shot, I mean really really shot.

__________________
Henry Bofinger
1989 560 SEL (black/black)
2001 Audi TT Roadster (silver/grey)