Disconnect - connector (this seems to be the ground). Disconnect + connector.
Loosen the clamp in front of the battery.

Lift the battery.

But the battery seems to be bonded to the rusted bettery tray.
When I pull harder, the whole car comes up.

Is there any other hidden clamp?

There is only one clamp on the W126. Have you tried possibly prying it out?
-Joe

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'81 MB 300SD, '82 MB 300D Turbo (sold/RIP), '04 Lincoln Town Car Ultimate

Sooner or later every car falls apart, ours does it later!
-German Narrator in a MB Promotion Film about the then brand new W123.

W124. (1992 300D).

I actually removed the clamp. But the battery does not come out.

I thought of prying the battery out, I did not find enough space around battery to pry it out.

Sounds like a bizarre problem. Assuming that you removed all of the brackets, I would then pour some hot water mixed with dishwashing detergent, between the bottom of battery and its tray. This should loosen-up whatever is making the battery stick to the tray. Repeat several times if necessary. Wear eye protectors, just in case.

If still stuck after several attempts, then you can try a combination of Hot water mixed with 25% vinegar.


Phil

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'95 E300 Diesel, 264,000 Miles. [Sold it]