It's about time to change the transmission fluid, transfer case lube, and differential lube on my X-Type.

I've got all the information as to how to do these, but I am wondering about a couple things....

1) Does the differential simply use Synthetic 75 W 140 gear oil or does there need to be an additive like for limited slip differentials?

2) Looking at the Power Point tutorial on the transfer case lube, it shows the transfer case completely filled (the oil level in the tube is above the height of the transfer case). But isn't the plug on the side of it made for checking the level and adding some when it doesn't run out? If it's for checking the level, then wouldn't filling it completely be too much oil? Should it only be filled until it runs out of the check plug?

 

I think in that PP he is flushing the transmission so he has the car on stands and running in gear. He has it in the clear tube to visually see the level.

Transfer case and rear dif use the same 75W 140 Synthetic. And it's only about 660ml for the TC, the rear dif has the inspection plug, fill it to just below.

Auto tranny is different, there are a couple of trains of thought. Flush it like in the powerpoint, so it's 5 or more liters, or drain it, should drain about 3 liters, then add what came out, or put it on stands, lower the left side to drain it, remove the inspection / level bolt, level the car, have the engine running have someone with foot on brake cycle through the gear while you fill into the opening under the battery with the rubber plug in it until fluid comes out the level hole.

 

Basically then....

The TC level shouldn't be above the inspection hole and NOT to the level in the PP (above the TC case level in the tubing). The proper level then IS ot the point it begins to run out the plug.

The rear differential doesn't need any limited slip additive or special lube with the limited slip additive already in the mix.

Correct?

 

The problem is, the drain plug on the side of the TC is not for checking the level. If you only refill until the fluid just begins to run out you will be as much as 400ml short of the recommended 600ml capacity. This is assuming you meant doing this while both sides of the vehicle are at the same height.

It is necessary to fill the TC beyond the level of the drain plug hole in order to achieve the 600ml fill. People have done this by using the valve/tubing method to fill beyond the drain plug level. This is because the real fill plug is actually on top of the TC, unreachable while the unit is in situ. Assume that after draining there is approximately 200ml still in the bottom of the TC pan.

 

Perfect explanation...thanks!!