Oil Cooler

Will a new oil cooler or transmission cooler operate properly in a 73 Mercedes 220D?

(after modifying the connections)

Why wouldn’t it?? It’s not a mechanical device. It’s just radiator that the oil flows into.

For what purpose?

Assuming it has the same flow and heat transfer properties and it will fit in a position to get the proper air flow etc. Sure. Get one too small etc and of course it will not.

The Original cooler leaked a lot, and the current cooler from a 69 Merc is also leaking.

What Joseph said. If its flow or heat dissipating characteristics are insufficient, you may toast your tranny.

Also, if it creates too much of a restriction to the radiator you may have engine overheating problems.

Have you been unable to find a direct replacement?

I assume you are trying to replace the engine oil cooler, not the transmission cooler (in the radiator)? I would find the correct part (maybe only available from the dealer or used). The cooler operates at full oil pump pressure (up to about 7 bars, I think) and it’s failure is very bad for the engine. As an alternative, you might want to see if a cooler for a 616 engine will fit, they are more likely to be available used. I just ordered a new one for my 617 engine, they are around $600.

I found a used replacement, but my fear is spending $300.00 on something used and it leaking in 6 mos. The way I look at it is, the original Cooler was used, and so was the 69 cooler. The original cooler was not leaking when I bought the car, but the car was rarely driven. I drive it every day. I bought it to drive on WVO, I’ve driven at least 80 Gallons of WVO thus far.