Finally found some on Ebay. Lube King. $43 for 2 gallons shipped to my door. From the description its what I need. Searched Amazon also and there its out there but not many good choices. I will need 2 quarts for break in and 2 for the final fill. That gives me a spare gallon. I can also use it in some of my old farm equipment. Thanks for all the info. Seems like they seem to me that they are always discontinuing stuff that I have been using for years. Part of the price for living so long I guess.

StaLube has a GL4 that is a hypoid but claims it is formulated not to hurt yellow metals. Thats what I have been using.

Just to add to, or possibly clear up, some of the confusion. I learned a lot...

http://www.widman.biz/uploads/Transaxle_oil.pdf

That's the first place I looked. He doesn't address GL4 or GL5. It's a Ford Toploader. I know a lot of you are running Toploaders.

http://www.davidkeetoploaders.com/specifications.htm
Here you go.

Durham Missouri

As long as it's non-hypoid oil you should be OK. I don't know if that exists in a GL4/GL5 rating, though. Is the trans original to the vehicle or a swap meet/salvage yard treasure? If it's original or you know what it came out of the shop manual will have the specified gear lube listed. If you don't have a shop manual someone here probably does and can look it up.

I understand the potential problem with GL5 in transmissions. My problem is finding something only rated GL4. The question is will something rated GL5 and GL4 cause problems with the brass syncro's?

NAPA has a mineral based gear oil for transmissions with yellow metal parts. I think it has a GL-1 rating. I'd have to go out to the shop and look. I put it in my T85. It was fairly reasonable on price also.

Durham Missouri

Any type of hypoid gear lube is not recommended for transmissions that have yellow metal parts, i.e.: brass synchronizers, etc. The hypoid additive attacks the brass parts under heat and pressure, causing premature wear.

Regarding the rear end, you probably do not need any additive nowadays as nearly every gear oil there is already has it.  Finding a gear oil without it is very difficult.



Lawrenceville, GA