I am going to drain and refill the tranny with Mobile 1 Tomorrow and was sitting here thinking,I wonder what everyone else does about the transfer case? Any need to drain it? Or is a tranny flush with the return line from the cooler trick good enough?

 

Grab another OEM filter for the tranny too, they're crummy but better than nothing. If you are really energetic, dieselsite has a nice external tranny filter, pressure gauge and flush valve you can put on.

 

The two are separete. Right after I bought my truck I changed every fluid. I was shocked to see the transfer case had the worst looking oil of the whole truck. All black. So I have decided that for my six speed and transfer case it gets an annual change with Redline MTL. Yes it's expensive, but WAAAYYYY cheaper than rebuilding.

 

Thanx Kwik,, Any Idea how many qts the transfer case holds? Any special procedures for flushing it, or just drain and fill? I have 20 qts for the tranny, but will have to run to town in the morning and get some more for the transfer case.

 

Two or three if I remember right. Just drain and fill. The plugs are on the back side of the case. Remove the fill plug first so you know that you will be able to fill it up once drained. Once drained simply refill to the level of the plug.

 

Gee Kwik......that sounds like the voice of experience. LOL

 

It only takes ONE TIME drilling out a stripped fill plug with a 90 degree drill head in cramped quarters. Never again. LOL.

 

Yep....I hear you.

 

I'm in the process of doing the exact same oil change - finished the transmission change last night. I looked at the owner's manual last night - capacity is 2 quarts for the transfer case, assuming your's is the same as mine. You're gonna like the difference the synthetic makes!

 

what's everyones opinion on changing out all the fluid in the transmission, i know the original poster said he picked up 20 qts. for the automatic, that leads me to beleive he is either going to suck the oil out of the transfer case (how i dont know) or drop the transmission which seems like a huge hassle just to change fluid.

how else could you get every last drop out of the transmission? .. also i've heard mixed reports where it might dislodge some gunk in the process and royal screw up the transmission.

 

Here's what most Diy'ers do (my self included).

These instuctions can be adapted for just about any auto tranny.

https://www.ford-trucks.com/article/...nsmission.html

 

Heres what i did,,
I drained the convertor and pan, then i took both lines off the rear of the tranny and blew out the cooler with air,, I only used 40psi and probably blew out 2 qts of tranny fluid just from the cooler. I have heard people say you shouldnt do this, I feel like 100 psi would probably be dangerous, but 30-40 psi shouldnt hurt anything.There was no sludge or anything, just clean fluid came out.I just never liked the idea of doing the flush with a flush machine or from the lines of the cooler, just my personal opinion. I also drained the transfer case and my plugs were not tight at all, barely snug, but showed no signs of ever leaking.I did use some thread tape on the plugs before i reinstalled them. All i had to refill the transfer case with was the long funnel i use for the tranny dip stick tube and i couldnt get enough of an angle on it so you had to really pour it slow or it would run back out on you, not fun.!! One of those little pumps or even a spout for qts of oil would have worked much better. I used about 2 1/2 qts to refill the transfer case, but i'm sure at least a 1/2 qt ran back on me and the ground as i tried to pour it too fast.The fluid in my transfer case was almost black, It had never been changed in 65000 miles and i probably use my 4x4 about once a week and never abuse it.My tranny has been serviced every 20,000 miles since new, and the filter was changed about 25,000 miles ago, so i did not change it this time. I have read where tranny filters have been cut open after several 100,000 thousand miles and were not even 20% clogged. Of course if you had a tranny failure it could be clogged up, i've never even had anything on the magnet.After all that was done i poured 8 qts back in the tranny, cranked the truck and let it run for 5 minutes,added 8 more checked the tranny and added another 1 and its still full this morning.
Am I writing a book here?
As for the shifting after Mobil 1 Synthetic,,, Not sure I like it,, Its smooth, almost like it was from the factory,before the tuner. It shifts fine, but it was way more firm before the change to Synthetic. I pull my bass boat everyday, and like everyone else at times i just cant resist sticking my foot in it, a firmer,quicker shift creates less heat,and extends clutch material life, so not sure I like it just yet,trying not to worry.Might change my tuner to Performance tow and see if that firms up the shifts,tow safe program was firm before,but not now.I guess I never thought changing to Synthetic ATF would make that Kind of difference in shift quality.Guess I will try it for a few more days before i worry.!!

 

MrBass congrats on the good job.

 

What about the rear axle? Same drain and fill as the trasnfer case?

 

[QUOTE=westladog]What about the rear axle? Same drain and fill as the trasnfer case?[/QUOTE

Mine doesn't have a drain plug. Had to remove the cover.