The speedometer (driven) gear seal on my TH400 was leaking so I replaced the seal and the leak stopped but apparently tranny fluid got into my speedometer cable due to the leak. I first suspected it because my speedometer needle was smooth but now jumps while under 20 mph. I disconnected the cable from the transmission and let it hang low to drain and some fluid has drained from the cable housing over the last 48 hours. Anything else I should do?

If speedo cable is 20+ years old just replace it and lube up the new one before installing.

It's only 5 or 6 years old. If it was easier to replace I would but it sure is hard getting up under the dash.

You could reach under the dash and pop the cable off the speedo and slide the cable out and lube up the cable and slide it back in the housing. Also check that the square of the cable is getting inserted far enough into the transmission gear and that the plastic is not rounded off where it should be square.

Understood. Is white lithium ok or is there something you like better?

A graphite based lube is best
The white lithium hardens over time

Thanks for the recommendation.