Transmission Oil - 80w/90 vs SAE 40/50

[ctappan94]

I know there's just about 10 million threads on it, but I've gone through them all & they ALL show different answers...

I'm looking for a smoother shift & an oil that will perform to the best capability.

I heard that SAE40/50 doesn't have extreme pressure additives, while someone else said Spicer stated these trans's shouldnt use extreme pressure additives...

Someone said the army only used 80w/90 to cut costs...

Just gimme the best option !

 

[DieselBob]

Well I run this. Have about 500+ miles after fill and no problems yet. Shifts nice in summer and winter. Meets Dana/Rockwell 50 weight requirement and is yellow metal safe. There will be as many answers as members but that's what I am running in the transmission and transfer case.

http://www.amsoil.com/shop/by-produ...ife-synthetic-transmission-oil/?code=FTF05-EA

 

[shenkmen]

At the risk of starting another war...

Non-detergent 30, 40 or 50 wt was originally spec's by Spicer for the 3053a. I'm running it in my deuce and it shifts easier.

There's lots to read on this subject here.

 

[Flyingvan911]

I use 80w90 now and it's nice. I am going to swap it with 50w soon and see how it does.

 

[ctappan94]

alright guys, thank you. Think I'm going to try the SAE50 and see what it's like. Thank you for everyone's input

 

[welldigger]

I run 40wt non detergent motor oil. It made shifting a bit better. The synchros seem to mesh better.

 

[MyothersanM1]

It's not a Deuce, but I put Rotella T1 50W in the 5-ton. It's much smoother than the the 80W-90 and is Spicer/Dana recommended.

 

[Flyingvan911]

That's what I got was Rotella T1. When I replace the output shaft seals on he transfer case I'm going to switch.

 

[MyothersanM1]

Oh,yeah, I put 50W in the transfer case also.

 

[jnbullock]

New member and a new owner of a m932a2. Just drove her back to Tampa from Atlanta without any problems. I read the manuals for the transmission and was surprised that this one had transmission fluid instead of oil. It came with extra cans of train fluid. I changed out the filter and the fluid looks new. Any thoughts on why?

 

[ctappan94]

Transmission fluid like SAE 50 but synthetic?

Hey All,

SAE 50 is hard to find & I prefer it used in my transmission. However.... Is there a synthetic or conventional fluid that is similar to SAE 50, excluding GL 5 80w/90 MT1. I dont want to use that. Can I use a 5w 50 or 10w50, etc etc.

thanks@

 

[doghead]

Why don't you want to use the correct oil?

You do not want to use synthetic. Issues have been reported.

If you want to deviate from the norm, you'd better do your homework(or you'll pay).

 

[ctappan94]

Well i mean can i use the recommendedconventional SAE 50 but not a straight grade (a multi grade) like 10w 50 or 0w 50 or 15w 50, etc

 

[doghead]

The military used GL-1. Not 50W.

If you want to use 50Weight, you need to use straight 50 w, not a milti viscosity.

One has degergent and one does not.


Why not use GL-1, or GL-5?

 

[ctappan94]

The military used GL-1. Not 50W.

Im aware but i was told that was for cost savings and that spicer actually recommended sae 50 straight grade

 

[doghead]

It worked fine for the last 60 years.

 

[doghead]

If you can't find 50w local, then you can order it online.

Why make it more difficult than it needs to be.

 

[Karl kostman]

Use the same oil that has been used forever in these trucks, and make positive it GL-1 or GL-5 compliant, in other words YELLOW METAL FRIENDLY, Very important!
KK

 

[shenkmen]

New member and a new owner of a m932a2. Just drove her back to Tampa from Atlanta without any problems. I read the manuals for the transmission and was surprised that this one had transmission fluid instead of oil. It came with extra cans of train fluid. I changed out the filter and the fluid looks new. Any thoughts on why?

Automatic transmissions use a flavor of automatic transmission fluid. Don't you have an automatic in the 923?

 

[welldigger]

Tractor supply stocks 40wt non-detergent. I'm unsure if they stock 50wt.