drive train fluidids

[HFFH]

so i was under my rig yesterday a noyiced my transfer case is wet. never noticed it keak in the drive way though. how do i chech, drain and refill my transfer case. hoh much should i put in in. also the same question about the rear end. what fluids would be best for either. its my 1st 4x4

 

[tonydiv]

I would open up the fill plug on the back side of the case and stick my finger in it to see where the fluid level is. It should be pretty close to the bottom of the hole. In fact some fluid may even come out when you pull out the plug. If you can put your finger in and can't reach any fluid, it should be topped off.

I know on mine, the fluid was just ATF. I replaced it with a high quality synthetic tranny fluid when I got the truck.

According to Ford, the rear diff is "lubed for life" (what a load of crap) Depending on which rear end you have and what diff it has, it takes a synthetic gear lube. You'll have to check the manual for the exact weight.

 

[Racenut]

Also if you have a LIMITED SLIP REAR DIFF. MAKE SURE YOU USE THE FRICTION MODIFIER ADDITIVE or a brand of gear oil like royal purple that has the friction modifier in it already. If you do not use the friction modifier then you will burn out the clutches in the limited slip.

Also since you state that it is a 4x4 make sure to change out the front diff oil as well.

 

[tonydiv]

You know, that last part is a really good point. I hear tons of people saying "I hardly use 4 wheel drive, I don't need to change that front diff fluid". But what most people don't know is that on the Gen 1 trucks, the driver's side axle shaft turns all the time, and in doing so it turns the spider gears in the open diff. It doesn't turn the driveshaft, because the passenger side axle shaft gets disconnected in 2wd.

The bottom line is that the front diff fluid gets mucked up whether you use 4wd or not, so it needs regular attention.



Later trucks have IWE (integrated wheel ends) and may not have the same issues, but I'm not really that familiar with that setup.

 

[nvycrmn]

i agree with all of the above statements. there is a "how-to" on how to change your rear diff fluid. super easy. even has pics!

 

[HFFH]

i havent looked yet is ther drain plugs on the front diff and transfer case or does it have to be sucked out? also what would be a good fluid weight/brand to use in both? mine is awd all the time
no 2wd option so i know i should do the front!