How do I know exactly what model I have?

[scottladdy]

This met with some resistance as well. Transfer cases had always had gear oil in them and a number of folks couldn't accept the ATF and switched out lubricants. Usually this resulted in failure.

So, fully understanding that we are way off topic from the original post, one of the common misunderstandings is that ATF is solely a hydrualic fluid. While it does support that function, it also serves the function of a gear oil. Automatic transmissions usually have gears in them as well, subjecting the fluid to the same shear forces as non-hydraulically shifted transmissions. A transfer case is a transmission.

There is also confusion regarding viscosities. People see a 90w gear oil and assume it is significantly thicker than a 40w motor oil. However, in reality they are nearly identical.

I would never use an ATF in a differential. Well, almost never as many front wheel drive cars with automatics have the diff "built into" the transmission case and share the same lubricant. However, for a typical separate differential that specs out a gear oil I will only use gear oil. The reason, the hypoid gears in a differential impart the greatest shear forces on an oil which can create "boundary lubrication". Gear oils have additional EP and anti-foaming additive packages which are designed to reduce that possibility. However, in a 205 or 208 transfer case I see no issues with using the specified ATF. Just make certain to change it regularly.

 

[ChrisG]

I was actually quite pleased to see this truck had the front locker in it regardless of what model it says in the door and the vin.....lol. The guy I bought it from had two of these trucks and stripped the other for parts to use on the one I have now and still had the axles saved in a shed which were out of a 1028...i m still tryn to get him to give them up. Would love to have a spare set or set for another project.

 

[Recovry4x4]

So, does it have rear helper leaves?

 

[Keith_J]

Differentials typically require special lubriction because of the hypoid gearing imposing extra sliding motion between the faces. Spur and helical gears are much easier to lubricate.

 

[ChrisG]

Are you talking like over loads on top of main leaf pack with tabs mounted to frame? It does not have those...

 

[Recovry4x4]

Are you talking like over loads on top of main leaf pack with tabs mounted to frame? It does not have those...

In the absence of those I'm confident in saying it's an M1008. It's great that it has the trac-loc in the front.

 

[Keith_J]

Most likely the front axle was swapped late in service.

 

[the skull]

Guys, my M1008 has the plate on the cab, says M1008.
It also has the helper springs on the rear. I thought
all 1 tons had helpers.
No helper springs means it's a 3/4 ton where I come from.
I bought a 10k gvw truck from my uncle years ago, a GMC
Sierra 35 (1975 vintage) that had springs that would have
shamed a dump truck.
Being a farmer, Uncle Willis added 5 leaves (each side)
after he got her back home from the dealer. But the spring
pack was pretty healthy to start.

 

[Recovry4x4]

Vin on a 1028 will start with 1GCHD, and I think a 1008 will be 1GCGD

Guys, my M1008 has the plate on the cab, says M1008.
It also has the helper springs on the rear. I thought
all 1 tons had helpers.
No helper springs means it's a 3/4 ton where I come from.
I bought a 10k gvw truck from my uncle years ago, a GMC
Sierra 35 (1975 vintage) that had springs that would have
shamed a dump truck.
Being a farmer, Uncle Willis added 5 leaves (each side)
after he got her back home from the dealer. But the spring
pack was pretty healthy to start.

That 4th character in the VIN determines the GVW and subsequently the need for the overload spring on the top.

 

[the skull]

1GCGD for me.

 

[Csm Davis]

Okay does anybody know where the Vin number is on the frame. And as to the OP's post any truck that comes out of the military can and usually does have parts that the manufacturer did not put in them. If you are the mechanics and you are fixing a truck for your brother and cost is not your problem do you put the open differential back or the limited slip? I will stand up and say I would and have upgraded many things in service that might not have came that way. Just like a LDS in a M35. If I can help my brother in the field and know it won't hurt anything but the budget I did it. I will give you a example I found out that they were only putting the geared lug wrenches on dump trucks and that they were not building anymore dumps at RSMS so I told the guy in charge of putting the BII on the trucks to put one on each wrecker or tractor until he ran out. They would have been scrapped if not and I hope I made at least one soldier have a easier time changing a flat.