Chrisreyn

ok, i have always driven manual's before the truck I just got, its got he 518 in it.
Looking under the hood a few days ago checking for leaks and noticed there is a cannister or cylinder mounted on the passenger side of the block, behind and to the rear of the oil filter. It looks like it is plumbed into the tranny and the oil cooler...

I haven't been able to find a picture of it, and haven't heard it mentioned in here before...
what is it? a cooler of some sort? the cylinder looks like it was designed to hold pressure, so is it a vacuum reservoir?
just what is it and what does it do????

92DIESEL

it's a cooler/ heater for the trans fluid.

When you first start and the engine builds heat some of that heat is drawn into the trans fluid via that canister (i don't know the actual name)

Once the heat is up it becomes a cooler for the trans fluid letting the engine coolant absorb some of the heat from the trans fluid.

It is very important to leave in from what I've been told by smarter men than I

Hope this helps,
Michael