Too bad nobody sells a metal lever action pump that screws onto a gal. container, so you could use it while under the car watching for overflow. I thought about converting a unit designed for 5 gal. bucket use, but likely not worth the trouble for a job only needed every 10,000 miles. I HAD fabbed up an inexpensive plastic, easier to use, higher volume hand pump rig, but sitting in lube for years destroyed the rubber seals and rendered it useless (thus the cheapo low volume pump I resorted to). Guess I'll just get a 2nd dedicated $10 pump and heat up the 90W first next time after transferring it to an empty view-window container (and keep up my arm strength training regimen).

6 VOLTS/POS. GRD. NW INDIANA

I see no issue using the 85W-90 as I use the much heavier multi-grade in my own T-85 O.D. tranny.  Only drawback I see to using the heavier oil (85W-140?) is the overdrive is somewhat sluggish in engaging when the oil is cold.
 
Here’s a picture of the gear lube pump I fabbed out of pieces laying around the shop.  It uses a Y-Block gerotor oil pump as the actual pumping mechanism with the handle being made out of a well used Y-Block oil pump drive shaft.
 

Lorena, Texas (South of Waco)

So, I found the older grade of lube online (discussed in an earlier thread) that shouldn't corrode my brass syncros, and ordered a couple gals. (Sta-Lube GL-4). Several minor problems however:

1. It is 85W-90 (my T-Bird shop manual recommends straight 80W). The narrower index (80W-90 GL-5 I WAS using is noticeably less viscous when cold) shouldn't really be a problem in my (mostly fairweather use) BW overdrive trans. (?), but for the next change I will be sure to bring the stuff inside first to warm up, since as it had been sitting in my 40 degree F garage, using the hand pump really wore me out!
2. The Sta-Lube gallon container has no view window to keep track of content volume. As I always pump the lube into the higher OD fill hole (so as to be certain the OD unit is completely filled) using a custom-made, screw-in tubing adapter (necessitated because of the OD components obstructing the fill hole depth) and stop pumping when it starts to overflow out the trans. fill hole, this thicker viscosity's flow delay caused quite a lot of lube overflow/waste, since if there had been a view window I would have just stopped pumping at 4 1/2 pints and replaced the fill plugs (or taken a long break to wait for the lube flow to catch up).
3. The container is an odd (in between) size/height, so my longer hand pump pickup tube is too long (I am still using up the GL-5 which comes in a standard 'tall' gal. container in my differential, but the optional tube that was included with the pump only fits a standard 'short' gal. container). So, in order to pump the lube mostly out and not waste or juggle the last couple inches, I need to buy another pump (or some additional tubing cut to size and then bother with the mess of frequently swapping pickup tubes & fill nozzle adapters).

It's always something! (Sorry, just needed to vent).

6 VOLTS/POS. GRD. NW INDIANA