M923A2 Engine Service

I'm doing some service on my truck an M923A2, rebuilt in 2012 at RRAD,and have a few questions:

1- Engine Oil- the TM says 15/40 but I've read other users using 10 weight, what are some of your thoughts.

2- Fuel Filters- my truck has the filter on the engine and another canister behind the front drivers side wheel. The canister has a pet cock on the bottom and I was able to open it and some liquid came out, I mean some, a mix of water and diesel, it seems that it's not hooked up? I ordered the filter for it anyway but was surprised to find very little came out.

3- The zipper type seals behind the front wheels are dry rotted and cracking grease is visible, I ordered new seals but closer inspection also revealed some oil. Should I pull the wheels and change the seals? Now going further, my truck does have CTIS but not operational and I plan on removing it, do I still need the CTIS seals for the axle in addition to the other seals?

4- Rear axle- on the rear axle in between the axles there's a cover that looks to be leaking? It's not the axle plate but another in between, you can see this from the side of the truck between the tires and under the leaf springs. Is there a gasket for this plate, it looks like a soup bowl upside down and mounted on the side of the bogey.

i appreciate any help the members can give me, the TM is great but my patience runs out trying to use them and find solutions.

1. 15/40 for sure, the 10w is for the Transmission. Look at the Lube order TM that will help.
2. The petcock on the bottom is for water drain.
3. You may have an inter axle seal leaking.
4. If it is not dripping out I would not wrong about it.
If you have an MV you will have oil leaking, just when? LOL

You need to understand how to use the TM, they are a great help.

I've read the TM lube order and if I remember correctly the transmission called for 15/40 as well. I also read the power steering called for 10 something, is that 10 weight motor oil as well?

I looked at my LO and it reads 10w for the trans. and you are right on the power steering.
But you need to look at it to make sure it is oil and not Dexron III. I have a m936 that came with Dexron in it.

Moved to the proper forum