My 744's trunk lock solenoid has been making a noise of teeth skipping on a gear since I got it. Is there a known fix for this, or do I need to source a replacement lock or solenoid or something? For now, I have just unplugged the thing, but it makes a terrible noise unless I keep it in the "super locked" position where you can only unlock it with the key.

How is the little flap that protects the key hole?

On our 88 745 the rear hatch lock rusted up solid and was beyond repair because this flap was not working.

It is very dirty and gritty at the rear of the car.

It isn't a solenoid, its a DC motor that runs a block up and down on something
like the lead screw on a lathe.
Maybe there's something interfering with the linkage?
Maybe it's toast, but you can take it out and look at it for some obvious fault before trying to find a replacement.

Good luck, Bill

Should be a disconnect 12 volt plug to the motor.

Yes indeed. I disconnected it the night I made the post. I don't want it to tear itself up any more than necessary in the mean time.

Clean and lightly lube the latch piston and linkage. Last resort is to open up the lock motor housing for cleaning and lubing. It’s rare to have to replace anything with enough cleaning
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Dave -still with 940's, prev 740/240/140/120 You'd think I'd have learned by now