M923a1--can i use 10-30 oil in trans

[gem1410]

My trans oil level is at the bottom of the stick at idle --i can not find 10 weight oil----can i use 10-30 to top it off or what do you suggest--thanks

 

[Rkrug]

This is what I would suggest.

 

[westfolk]

I wouldn't put hy-tran in the tranny. But it's not mine. I use Dexron 3.

 

[commandojeff]

You can use 15w-40 to top it off. Or the Dex 3 as already stated by westfolk.

 

[Carlo]

Use anything other than DEX 3 and it will shift hard from 1st to 2nd and shift late.

 

[gem1410]

Why would you top off 10w motor oil with trans fluid?--The mil spec oil in this trans is 10w motor oil and it is clear--dex 3 is red--

 

[Rkrug]

I think some transmissions on these trucks run the red stuff whereas some run the clear, I've seen both before, but when I had to add fluid to my trans when I added a pto this is what I used and I have had no harsh shifting or transmission problems.
I think if you just ad the same type that is in there ( don't mix) you should be fine.

 

[juanprado]

dexron is very close to 10w but is dyed red and of course has the tranny additives that 10w does not.
Dexron can mix with 10w.

 

[gem1410]

thanks--I did not know that--this truck also has a very hard downshift 2nd to first--the whole drivetrain jumps---any ideas on that==thanks

 

[juanprado]

many threads on here on the 5 ton forum. Allison recommends their Proprietary fluid now but spec'd dexron previously. Military used 10w because it was in their supply system. Does not make sense to me because 10w is plain ole oil and dexron has a specific additive package for t-parts.

Most folks who have m939 and changed filters & dexron report better shifting and no/reduced harsh shift points. Mine came with dexron already from military and has no shifting issues.

There is also an adjustment that can be done. There is also threads on that in 5 ton forum.

 

[quickfarms]

The hard shifting tends to be incorrectly setup transmissions. Read the Allison manual to see if your shift points are set correctly. The hard shifting is another adjustment.

 

[Carlo]

Mine 931A2 came with dex 3 and shifts like a allison should. My 923A2 came with 10w and would scare you to death when it shiffted from 1st to 2nd plus needed more gas pedal to complete the shifts. I changed to Dex3 and the problem stopped. I dont care so much what military specs are for trnas oil. I do care what Allison says.

 

[Carlo]

I also adjusted the shift points to lower RPM. Many people choose higher RPM shifts.

 

[gem1410]

Carlo====how long did it take you to set up the shift points on the a2-----is the Allison manual easy to follow --I also have an M923a2 and it shifts at very high rpm--------thanks alot

 

[Carlo]

Carlo====how long did it take you to set up the shift points on the a2-----is the Allison manual easy to follow --I also have an M923a2 and it shifts at very high rpm--------thanks alot

Did you get my reply?

 

[gem1410]

Carlo---I did not get your reply about setting the shift points and down shift adjustment------where did you send it--thanks

 

[Carlo]

Carlo---I did not get your reply about setting the shift points and down shift adjustment------where did you send it--thanks

By the injection pump where the gas cable hooks up to a type of cam you will see a cable befind this going down to the trans. Remove this and screw it out so there is more play. Start a few turns at a time. Try it to see if you need more. This will remove some pressure and allow smother shifts up and down but change the oil to dex 3 too. Please let me know who it goes.

 

[plowboy]

Dextron is an SAE 10 weight oil. Universal Tractor Fluid (ie, hydraulic/transmission oil) is generally SAE 20 weight. In a 600 series transmission, Allison calls for SAE 10 in light duty, SAE 20 in severe duty. If you are driving a service truck around on the highway, Dextron is correct. If you are running a floater truck spraying in loose dirt with 66" terra tires, then 20 is the right oil.

 

[Carlo]

I remember my uncle using "hytran" in his IH tractors. Seems like 100 years ago. He sweared by it.
Good info Plowboy. Thanks

 

[commandojeff]

When you drain the fluid, about how much do you get out of the system? Just by using the drain plug to drain it? I'm curious because I would like to buy some new fluid but don't know how much to buy. Thanks guys.