M923A2 Transmission Fluid

[Iggy913]

I've searched and searched and know what the TM says, but I can't find any OE/HDO 10 weight oil in the Virginia Beach area. My trans has been working fine but I haven't changed it or the filters since I got the MV last year. I've read SO MUCH on Dextron III, and the Allison equivalent my eyes are crossed. Can I get some help and recommendations.
Thanks for your inputs.

 

[Carlo]

If your going to be using the truck as it was designed use the oil specified in the TM but most of us use the light duty and Dex3 works fine. It even evens out the harsh shift up and down. I use it on all my 900 series trucks.

 

[jedawson1]

Hydraulic fluid in mine, smoothed out the 2 to 1 down shift except when its real cold. There are several viable options and many opinions for each. The TM is always the safe bet.

 

[Tow4]

This is what I used in mine. It has the Allison C-4 rating.

 

[Iggy913]

Ray,
Have you had a seal or leaks when you put in that oil? Just don't want to ruin a good thing. The only problem if you can call it a problem is the hard downshift from 2nd to 1st. Otherwise it's been shifting fine but I just want to do some PM and can't find the 10 weight oil in VA beach area.

 

[M35A2-AZ]

Look for a Petroleum supplier in your area and they should have it. I use Arizona Petroleum here in AZ.

 

[Tow4]

Ray,
Have you had a seal or leaks when you put in that oil? Just don't want to ruin a good thing. The only problem if you can call it a problem is the hard downshift from 2nd to 1st. Otherwise it's been shifting fine but I just want to do some PM and can't find the 10 weight oil in VA beach area.

Why would a seal leak? It meets the Allison spec. I have the Allison 654CR transmission, if yours is different then disregard what I said.

 

[NYC M923A2]

Sine this topic came up what it the advantages of switching the trans over to auto trans fluid? I would have to drain the system and replace the filters to do it. My truck was rebuilt in 2012 and it's the last service I have left to do. I already flushed the cooling system, motor oil changed, fuel filters changed.

 

[brock]

FWIW, My local Allison service center advised that 15-40 motor oil would be suitable for my SoCal climate.