manual transmission fluids

nbrskn

Senior Member
there was a thread before on this subject. discussed at length for
3spd and overdrive what type fluids. I cant seem to find it in the
arkives.


I have an overdrive from a 1968 ford f150 in my 46 ford. Used a 49 ford
bellhousing behind the 50 Merc engine.

any help would be appreciated.
 
Assuming you have the stock 46 transmission, Ford specified S.A.E. 90 in the summer and S.A.E. 80 in the winter.

LubeChart3.jpg


I use 80W-90. Don't know about your overdrive.
 
The flathead V8 types with overdrive used a GL-3 rated lubricant which hasn't been available for many years. Many now use either GL-1 with little or no pressure additives or they use GL-4 which has more pressure additives than the GL-3 had but less than the modern GL-5. It's the pressure additives that were a problem when a sprag freewheeling clutch is used as it is in the Borg Warner electric overdrive type transmissions. It has a tendency to slip if too much additive is in the lubricant.

If there is no sprag unit, you can use the GL-5 lubricants with no troubles.
 
there was a thread before on this subject. discussed at length for
3spd and overdrive what type fluids. I cant seem to find it in the
arkives.


I have an overdrive from a 1968 ford f150 in my 46 ford. Used a 49 ford
bellhousing behind the 50 Merc engine.

any help would be appreciated.

Do you mean a 1986 trans? With the top shifter in almost stock location? I have that trans in my AV8, they use a thinner oil than early Fords. I use Redline Light shock oil. It's expensive, but up there with the best.
 
A Ford Truck transmission in '68 was probably a heavy duty t85. Someone can probably post the BW overdrive owner manual. I have it as a pdf but can't get it to this reply. The last section is on lubricants, it says that SAE 40 or 50 wt motor oil is good, or 85 or 95 wt gear oil. It does say to positively NOT use an extreme pressure grease in the OD.
 
No . I mean a 1968 ford f150 pickup. Its a normal 3spd trans with a unit behind it. W
as an overdrive with a planitary gear system. solonoid and governor. I ve even seen one in a 1984 ford with a 460 in it.
yes the pressure addatives are not good. Overdrive booksays no.Hypoid fluids. Book
says 40 or 50 straight weight. But are engine oils ok in trans?
 
I use a lot of 100 grade SAE 50 motor oil in the helicopters. You can buy it in straight mineral too for engine break in. SAE 50 "engine oil" is the same basic viscosity as SAE 90 gear lubricant. They are catagorized and graded differently. Straight mineral would be the same basic lube as a GL-1 with no pressure additives. I use SAE 50 engine oils in my Harley Davidson transmissions and have never had an issue due to lubricant.
 
On my 49 Merc 3 speed with the BW O/D I use the Napa GL-1 90 wt gear lube and add Lucas Heavy Duty Oil Stabilizer to minimize the seeping thru the solenoid.
 
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