Depending on the idle speed, the response of the body is typical due to the applied torque.

When you shift to reverse, the back end of the vehicle will climb accordingly.

The diff mount might be tired, but it usually doesn't contribute to this phenomena because, although the rubber may sag, it's still relatively rigid.

You ought to check the diff mount anyway because they definitely do get tired due to the constant load on the rubber. I've got some photos in the archives that show the new mount versus an old one.

Thanks Brian. Do you have a URL to the photos?

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This area is typically used to brag about one's current or former automobiles.

Here's the two, side by side:

The one old one on the left,looked like mine.Then I lifted car ,and inserted the bolts wrapped in hose.They haven't moved,even in deep snow.

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1999 w140, quit voting to old, and to old to fight, a god damned veteran, deutschland deutschland uber alles uber alles in der welt

To just look at the old part, I would have not thought it were bad. I will order a new one. 27 years and 200k miles can do a toll on any rubber part.

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This area is typically used to brag about one's current or former automobiles.

It will still function fine...........the problem is the body drops by about 3/4" in the tail due to the old mount. If you are short on funds and don't mind the look, it can probably go another 20 years.

Funds no matter how plentiful will always seem short to me.

I will scope out a replacement and address during a future weekend.

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This area is typically used to brag about one's current or former automobiles.