This is what I did. I just soldered a wire lead directly into the 3.5mm socket on the back of the lehner. Then you can use any connector you want on the motor. I really think that the 3.5mm connector is a weak spot in the design of the lehner motors. I love my lehners, but the 3.5mm connectors are just not up to snuff anymore.
Heres a picture of what I'm taking about on the direct soldered wires. WOrks well. I have been using it like this for over a year with no issues.
