Trans fluid level in 10L1000

sno1 · May 16

Does anyone know the procedure for checking the transmission fluid level in the new Allison branded 10 speed behind the 6.6 gasser? Should it be checked cold, at a certain temp, while engine is running, etc? The dealer would not tell me the procedure for checking the fluid so I asked if I could buy a service manual, they told me that no service manual is available for the '24s, is this true? I think I need to find a different dealer.....

64BAwagon · May 16

It has to be running and at operating temp which I think is 140 degrees (the sheet is out in my barn)

It must be level. Remove the plug in the bottom of the pan (this is not a drain plug) If fluid comes out then screw the plug back in because its full. If nothing comes out remove the pipe plug on the drivers side of the trans case and fill it with ULV fluid until the fluid runs out of the plug in the pan. Install the pan plug and the fill plug. The pipe plug in the side of the case takes a 3/8 drive short extension just like a differential plug does.

Whatever you do dont shut the truck off with the pan plug out, it must be running.

Watch out for the catalytic converters, they will be very hot since the truck will be running

Scott

64BAwagon · May 16

I double checked the document and the temp should be 167-179 F

It suggests that you idle the truck or brake torque it in drive if you need to elevate the temp.

sno1 · May 16

6 hours ago, 64BAwagon said:

It has to be running and at operating temp which I think is 140 degrees (the sheet is out in my barn)

It must be level. Remove the plug in the bottom of the pan (this is not a drain plug) If fluid comes out then screw the plug back in because its full. If nothing comes out remove the pipe plug on the drivers side of the trans case and fill it with ULV fluid until the fluid runs out of the plug in the pan. Install the pan plug and the fill plug. The pipe plug in the side of the case takes a 3/8 drive short extension just like a differential plug does.

Whatever you do dont shut the truck off with the pan plug out, it must be running.

Watch out for the catalytic converters, they will be very hot since the truck will be running

Scott

Thank you very much for this, I really appreciate it. May I ask where you get this information? With our car (Honda CRV) I can log in on Honda website and access the service manual for a fee, do you know if GM has something similar? I am not having any luck finding any kind of service info.

Thanks again, I couldn't check it without knowing the temperature

bruceb58 · May 17

Temp needs to be 167F when checking fluid level. There is a thermal bypass valve that needs to open in order too check level properly

Edited May 17 by bruceb58

64BAwagon · May 17

15 hours ago, sno1 said:

Thank you very much for this, I really appreciate it. May I ask where you get this information? With our car (Honda CRV) I can log in on Honda website and access the service manual for a fee, do you know if GM has something similar? I am not having any luck finding any kind of service info.

Thanks again, I couldn't check it without knowing the temperature

I dont recall where I got it but the info is from a GM service document. Its hard to find service information on GM vehicles. Theres not a lot of it accessible for do it yourselfers, GM doesnt really want you working on your vehicle.

sno1 · May 17

I found a GM website where we can access service manuals for a fee. It costs $22 for three days. Just found the site this morning so haven't actually tried it yet

https://www.gmparts.com/technical-resources/service-repair-manuals

64BAwagon · May 17

6 minutes ago, sno1 said:

I found a GM website where we can access service manuals for a fee. It costs $22 for three days. Just found the site this morning so haven't actually tried it yet

https://www.gmparts.com/technical-resources/service-repair-manuals

I have a source for information but I have to be careful how much I ask them for since they are very busy.

A 3 day subscription would be very valuable if you had a big project coming up or a good printer (assuming the documents were printable)

Epsilon Plus · May 17

I have tried the subscription.

Once you get in there, click on everything you can and print to pdf and save on your computer. Everything you think you'll ever do to the truck. The pictures and torque info is worth the money.

Example:

Handy · May 17

On 5/16/2024 at 6:24 AM, 64BAwagon said:

It has to be running and at operating temp which I think is 140 degrees (the sheet is out in my barn)

It must be level. Remove the plug in the bottom of the pan (this is not a drain plug) If fluid comes out then screw the plug back in because its full. If nothing comes out remove the pipe plug on the drivers side of the trans case and fill it with ULV fluid until the fluid runs out of the plug in the pan. Install the pan plug and the fill plug. The pipe plug in the side of the case takes a 3/8 drive short extension just like a differential plug does.

Whatever you do dont shut the truck off with the pan plug out, it must be running.

Watch out for the catalytic converters, they will be very hot since the truck will be running

Scott

Wow, I never would have guessed this procedure! Removing a drain pan plug with the engine running and all the fluid is elsewhere! Thank you for sharing.

BCGM · May 17

you should be able to get , purchase at will any service manual for the 2024 Chevrolet 250-0 HD and like trucks !

I note SHOULD ! What happened to right to repair ?

64BAwagon · May 17

22 minutes ago, Handy said:

Wow, I never would have guessed this procedure! Removing a drain pan plug with the engine running and all the fluid is elsewhere! Thank you for sharing.

Its definitely counter intuitive to pull the plug in the pan and leave it out while the truck is running. There is a "standpipe" that extends upward into the pan. It is set so that the excess will drain into the standpipe and out the hole. This is what sets the level.

bruceb58 · May 17

I bought the OEM manual from factorymanuals.net. I gave them all my vehicle info including VIN and they gave me a download link for the manual in 4 parts. Would have liked it to be one file but it works fine.

Here is the PDF contained in my manual for ATF level check

ATF Fluid Level Fill.pdf

Edited May 17 by bruceb58

sno1 · May 17

58 minutes ago, bruceb58 said:

I bought the OEM manual from factorymanuals.net. I gave them all my vehicle info including VIN and they gave me a download link for the manual in 4 parts. Would have liked it to be one file but it works fine.

Here is the PDF contained in my manual for ATF level check

ATF Fluid Level Fill.pdf 72.27 kB · 3 downloads

This is fantastic! Thank you for sharing!

64BAwagon · May 17

3 hours ago, bruceb58 said:

I bought the OEM manual from factorymanuals.net. I gave them all my vehicle info including VIN and they gave me a download link for the manual in 4 parts. Would have liked it to be one file but it works fine.

Here is the PDF contained in my manual for ATF level check

ATF Fluid Level Fill.pdf 72.27 kB · 6 downloads

I am curious what it "officially" says about the level check in the rear differential ?

I have a service document that I cropped a piece of that says .4in or 10mm below the fill plug.

They are filled by American axle when the rearend assy is built. GM does not check them nor does the dealer during the PDI. Many on here (me included) have found their rear diff to be almost a qt low based on this procedure.

Mu understanding was that GM was made aware of it but there was no confirmation of anything actually being done about it. A couple of people asked their dealer to check the truck during PDI and reported that there was fluid added.