Who currently stocks SAE 90 gear oil?

[Tito Sobrinho]

Whale oil was used as a friction modifier in transmission fluid. In the 70s cars were made to run hotter for emissions purposes and the whale oils based fluids did not hold up under the increased underhood temperatures. Add in the moratorium on whaling and you get the transmission fluids you have today with their petroleum bases and red dye for identification purposes.

The red dye was incorporated into the transmission fluid right after its inception in order to identify the can fluid and an eventual leakage origin . It was very useful during the war for the Army mechanics.

[Jon S]

I knew about the whale oil, but here's a tid bit I just discovered on the web.  Never knew this about Type A transmission fluid:

"Type A was basically a nearly 50/50 mix of Type F (Ford) and Dexron (GM)"

[bill06447]

I knew about the whale oil, but here's a tid bit I just discovered on the web.  Never knew this about Type A transmission fluid:

"Type A was basically a nearly 50/50 mix of Type F (Ford) and Dexron (GM)"

Doubt it. Dexron replaced Type A. Dexron is Type A without the sperm whale oil.

Bill

[Glen]

I knew about the whale oil, but here's a tid bit I just discovered on the web.  Never knew this about Type A transmission fluid:

"Type A was basically a nearly 50/50 mix of Type F (Ford) and Dexron (GM)"

That came from Wikipedia and the author did not cite their source of that info.  I see that quoted on several other car forums.  I hope that mix does not cause any harm.   

[Jon S]

That came from Wikipedia and the author did not cite their source of that info.  I see that quoted on several other car forums.  I hope that mix does not cause any harm.   

Yes, Wikipedia is where I found it.  I doubt it would cause any harm because Type F became Mercon and Mercon and Dexron are now interchangeable.  My Lincoln was converted from Type F to Mercon back in the 1970's by the LM Dealer and similarly, the Cadillac Type A was "upgraded" to Dexron.

[TJ Hopland]

What a shop told me was type F had something in it that made it 'grabby'.   Reason Ford used it had to do with the type of materials they originally used in their clutches.  They thought that the combination of fluid and clutch material was the best way to go but later (mid 70's?) decided to go with a material that didn't need the special fluid.   Most of the time when you rebuild an older Ford you end up with the typical material and fluid too.

Putting type F in a GM transmission made a good one shift harder (for a while) and would usually make one that had just started slipping shift normally (for a while).   

We have a 93 Mustang that was starting to have power steering issues.   Got to looking at the manual and found out it calls for type F trans fluid.   Flushed it out and found some type F and its been happy.  Not sure how 'grippy' fluid helps a steering rack but it does.   

[cadillacmike68]

I have used 85/90 gear oil which I buy locally for many years with no problems.  It may be that back in 1957 gear oil was only manufactured as a single weight.  Multi-weight oil may not have existed then so only single weight is mentioned in the manual.

And the winner is.... Jay!

80/90 or 75/90 will be fine.

When the rear axle drops out because the diff seized up, don't come crying back to this forum