'87 300TD Transmission Woes

[Eric4]

Howdy y'all.

I've been wrenching on an 87 wagon for quite some time now. When I first bought it, the car needed a new engine head. Replaced the head, and drove around in the car for just a couple days before the transmission went out.

Original thread: https://www.peachparts.com/shopforum/diesel-discussion/417628-new-project-87-300td-10.html

So I sourced a replacement transmission from a local for a nice price. I was told it was operating perfectly and had no leaks. Some basic oring seals were replaced before installation (bowden cable orings, sensor orings, pan gasket, crush washers)

After swapping to the replacement transmission, none of my replaced seals leak, but I'm getting one from the bell housing unfortunately. It's a steady 1 drip per 5 seconds. Quite a frustrating revelation, but that's the price of a cheap transmission.

I drove around the block a few times, and it seems like the shifting was in order, so I'll likely reuse this replacement transmission.


The next step is to place an order for the potential leaking seals, but I'm not sure what should be replaced. Does anyone have a good idea of the culprit? Front main pump seal most likely?

Thanks in advance