Holy crap, what a day!!
I started off trying to locate enough gear oil to change it out in all four of my gear boxes.....no luck. Local mom/pop shop closed, AutoZone
only had three quarts, and Pep Boys only had one. So, four quarts is all I had to work with for today.
Since I have never done this before, I started out with a warm truck and did my oil change with Mobil 1 5w30 (and Mobil 1 oil filter) as I have done for the past 150K+ miles. All fine, but I took it one step further and actually replaced the drain plug with a new one along with the new washer. Fit perfect!!
Then ran the truck a bit to get the new oil flowing through...all fine.
Now on to the gear boxes.
Attempted to locate each of the gear boxe's drain/fill plugs. Front differential, rear differential, and transfer case were no problem, but I cannot find the plugs to the damn transmission ---- HELP on this please!!!
Having only 4 quarts to work with I decided to do the two easy ones for me -- the rear differential and transfer case.
I did the transfer case first. Was shocked that only just over a quart drained (yes I unscrewed the fill plug first -- thanks for the advice on that!). Was more shocked that it looked to be cleaner than my engine oil and it's NEVER been changed. No large metal parts or shavings and no sludge. Smelled a bit, but not overly awful. Was even more shocked that it only took a little more than a quart to fill it back up. All fine here.
Now moving on to the rear differential. A totally different story. I need new plugs and washers. Mine are badly corroded and in need of replacement soon. Got them off, barley, fill plug first of course. Then it drained........the crap that came out of my rear differential was nothing short of God awful. This crap smelled like onions mixed with bay mud and had the consistency something between soft ice cream and booger snot. I am not kidding, it was truly horrible. It puttered a few times while draining and chunks of sludge came out. It took almost 15 minutes to drain completely, and the truck had been run for a while prior to doing the changes. The goo was warm to the touch and it still was slow to drain. Also, when I unscrewed the fill plug at the start of this adventure a hiss came out of the rear differential's fill hole, as if it had built up some pressure in there....is that possible? Is that bad??
Ok, I digress......
Anyway, after it drained all the way I squirted some fresh gear oil in there and let it drain out again (hoping I would have enough to finish the job). That was a good thing, because a couple more sludge chunks fell out as the new oil passed through the gear box.
A close inspection of my drain plug revealed no large metal chunks or pieces of anything hard. The sludge appeared to have the color of graphite, though. Cleaned off the plugs and washers and filled it up.
All in all I had about a quarter of a quart of Mobil 1 75w90 LS gear oil left after this whole experience. Not bad.
Any thoughts on all this? Did I do alright for my first time?? Anything I could have done better or missed???
Thanks for any and all advice!!