fluid change

[amccomb]

I just recently bought a 66 k10, The guy I bought it from said it had been sitting for 4 yrs. So I am going to change the diff fluids and the tranny, transfer case. I am new to these old trucks, and to any project trucks for that matter. My plan is to take the covers off the diff's to get a look inside and see whats going on they both leak anyway. Whats the best gear oil to use? Can I use the same gear oil in the tranny as the diff's and transfer case. I guess I have a lot of ? so any info is good. Thanks in Advance!

[brokenspoke]

I'm not sure what a K10 is

[amccomb]

You dont know what a k10 is, is that a joke, its four wheel drive. c10 two wheel k10 4 wheel.

[neto]

I used the regular gear oil, it's like 75-90 on my suburban. There's a thread on here about oils. I don't think there would be any problem using the same oil for all three. I'm sure someone will have more information.

[amccomb]

I change the fluid on the transfer case it was pretty simple a drain plug on the bottom and a fill plug on the top. I want to change the fluid on the tranny but I cant find a fill plug? Its a 4spd. Any one have any info?

[aerotruk63]

On the tranny, I used to pop off the 4 speed shifter by the slight turn of the locking collar. So much easier to fill the tranny from the top. I used Lucas gear oil in one tranny that was a little stiff to shift, after leaving the truck for a couple of months and came back to it, it was smooth. Ran the Lucas through the winter months, felt fine. I like the Lucas products. Their stuff got our transport trucks out of a few jams.