I bought my '92 250 (351 5 speed) about a year ago. My uncle was the original owner. Shortly after he bought it, he had Warn manual hubs installed. He says the 4wd has been used no more than a handful of times since new.

Last year I had another (much newer) truck that was the go-to on snowy days, so I've never used the 4wd on this rig either.

Although we don't get many snowy days in my neck of the woods, it can get fairly nasty when it does snow, and I have some obligations that will certainly need taken care of should the weather really go south (elderly family members etc).

What all should I check out and test before winter hits to make sure that my 4wd is in good shape before I really need it?

 

Unless the u-joints in the front drivetrain(all 5 of them) have been replaced already it's a virtual certainty they are dry and siezed. To test thier health lock the front hubs but leave the t-case in 2wd and take it for a drive. make some tight turns at slow speed but also get it up to hwy speed or 50-60mph and listen for vibration, noises, and pulsations in the steering wheel when turning. If you have any of those symptoms the U joiints are in need of service.

 

I’d have a look at:

All fluids, topped up and good. Differentials and transfer case.
Trasfer case shifter? Does it shift nicely, or getting stiff?
All u joints, free and smooth? Greaseable? Grease everything if you can.
Battery. Have it tested at a local auto parts if you don’t have a volt meter or battery tester. You are looking for the voltage drop on starting - ‘battery health’, not just the static voltage.
Coolant condition. What is it rated for, temperature? Has it been watered down over the yrs..
Tires. General condition and age. As tires age the rubber compound gets harder, which results in poor cold weather traction.
ABS - does it work? Nice to have on these trucks, especially in the rear.
Heater/defrost - does it work? Do the the controls work?
Windshield wipers and fluid - do they work? good ones for snow / cold.


My experience with the premium (brass handle) warn hubs in cold weather is they become very stiff. A pair of channel locks in the truck would be handy..

A shovel in the bed. Snow brush / scraper in the cab, behind the seat. Personally I like a corn broom for sweeping the snow off.

Spare tire. Good? I also like the spare tire in the bed, much nicer than digging it out from under the truck in a snow bank on the side of the road… spare lug nuts too. And spare tire Jack and tools. Does the Jack work? Run it up and down.

Plus all the regular Mtce items, brakes etc.

 

I just went through and did this myself. I knew my front shaft vibrated, thought it was just joints, not that lucky. There's a part if the double cardan joint welded to the front of the shaft that can wear. If that parts messed up it's gonna to require a new shaft or someone who can cut and reweld shafts.

I had a heck of a time trying to sort through the various shafts offered at the local parts stores. Ended up getting a custom shaft made by Tom Woods.

Just mentioning this because I hadn't used the 4wd much on my truck either.

The transfer shifter can be a bear to shift too if it isn't used regularly.