Transmission oil change:
Prepare by removing the front bumper lower cover to gain access to the area under the radiator and transmission oil cooler. (While I was in there I replaced the left side fog light assembly.)

1) Drained 3.5 qts from transmission drain plug and from unhooking oil cooler lines, and blowing out transmission oil cooler.
2) Replaced transmission drain plug.
3) Added 6 qts new fluid through filler.
4) Started engine with transmission in park and pumped out 4 quarts through top oil cooler line.

Comment: This is how to pump new fluid through the torque converter and out the line to the oil cooler. Seemed to work just like it does with the Chrysler transmissions I have worked with. The oil was pretty dirty at first then got noticeably cleaner the last quart.

5) Added 4 quarts new transmission fluid though filler.
6) Started engine with transmission in park, moved through all gears while pumping out 2 more quarts through top oil cooler line.
7) Reconnected oil cooler lines.

Conclusion, worked well, drained a total of 9.5 qts out of transmission, added a total of 10 qts new fluid. Checked level, barely running out of oil check hole.

 

Rear end oil change: I normally remove the back cover but it looked like removing the back cover was going to be a major pain. I drilled a hole straight up through the bottom of the cast iron by the cover then tapped it for 1/8 pipe plug. The draining oil flushed any metal out of the rear end.

It was messy but worked well.

Drained out 1 qt and added 1.5 qts Amsoil Severe Gear 75-140.

 

Transfer case oil change: I changed the transfer case oil by removing the rear output shaft bearing housing. It was a bit of a job but worked fairly well. I got 400 mls out and added 550 Amsoil Severe Gear 75-140 through hose I installed to the side plug. Everything is fine.

Here's some discussion on it; How to replace a Transfer Box - Page 2

 

Jesse, I like your idea of using some braided line to simply keep the fill line in place. Then all you have to do is lean the car a little bit, remove the fill tube and the fluid drains out. This gives me an idea. he he he he he.

 

The transfer case output shaft bearings were pretty tight, much tighter than any tapered roller bearing set I've had experience with. So I'll be draining the the transfer case by removing the output shaft bearing housing next time - plus I'll probably take apart the rear output shaft assembly to check those bearings.

Apparently the X transfer cases were put together too tight on all three tapered roller bearing sets, ran across a guy who sells shims to set them up for the correct amount of preload.

 

Jesse, I know a lot of members here have experienced failures of their transfer cases and some of them complained about the cases actually cracking, leading to a loss of fluid. I wonder if the excessive pre-load is causing this. Which, in that case, if someone was to rebuild the transfer case and get rid of the excess pre-load, I wonder if that would then allow the use of power power safely? Just a thought.

 

That's an interesting thought. I never paid much attention to preload when I took that one apart. With the transfer gear bearing out that bearing set would have had no pre-load. The way to check the preload is to bolt the box together seperately for each shaft/tapered bearing set. The output shaft would be done by itself.



The differential you see in the picture is the transfer case front wheels/back wheels differential. The differential between the front wheels is in the transmission, and of course the differential between the rear wheels is in the rear end. The right front driveshaft is driven by a spider gear in the front differential (in the transmission) and goes through the hollow transfer case differential shaft. That is where the "internal seal" that seperates the transmission oil from the transfer case oil is. The front differential carrier in the transmission drives the transfer case input/differential shaft. The viscous coupling limits the amount of slip between the front and rear wheels.

 

Well after all the oil changes the car started howling when the outside temperature got cold. I thought it might be brakes since braking seemed to stop the noise, but after new EBC Sport Rotors and Red Stuff pads it was still howling, a weird harmonic howl. Greasing the center driveshaft bearing stopped it. I greased the bearing from the back with a needle, not from the front like some do. I was able to work the needle under the actual bearing seal and get the grease into the bearing itself.

 

Heh, mine does that in the cold. I just say that my cat is whining about the cold morning :-p

 

But yours is fake!


The driveshaft howl on our car is getting worse, and at warmer weather. It is a harmonic, I have to wonder if it is because of too tight tapered bearing set on the output shaft. When I had the output shaft housing off for the transfer case oil change it was so tight it couldn't be turned by hand.


I have a theory: The transfer case is aluminum, so is the output shaft housing. The gears and guts are steel. That means a too tight tapered bearing set is even tighter when it's cold, the aluminum housings shrink over the steel guts. So I wonder if that is why the driveshaft howls more when it's cold; if it's the too tight output shaft tapered bearing set setting up the driveshaft harmonic howl.


I have a plan: I just bought a 2003 transfer case with 33,000 carfax certified miles on it. During the rebuild I'll set the three tapered bearing sets' preload correctly. I wonder if doing that will change/eliminate the driveshaft's harmonic howl.