All-Mode transer case fill level

[dapfnp]

I drained the fluid from my 01 PF w/ all mode t-case yesterday. I measured about 2.5 quarts that was drained. I was able to replace (pump back in) less than 2 before it started coming out the fill hole. I did drive around the block, and tried to dd more, an did get a little more in, but still less than what I drained out. I did drain and fill on a flat surface, t-case was set to rear drive mode.

Unfortunatly, I did not completely remove the fill plug before draining, I just loosened it, so I can not say for sure if fluid would have come out of the fill hole, but I assume it would.

I read somewhere that the factory "overfills" this fluid. I can not seem to find any info whether this is normal (service manual and Haynes do not discus this - they only mentions capacity which was 3 1/8 Q). I was thinking of elevating the rear and filling more (up to same qty that was drained). Any help ASAP would be greatly appreciated as my seemingly easy 1 hour project has turned into a prolonged ordeal!!!! Thanks in advance for any help.

[Pwnin O'Brien]

Well when you drain the transfer case you definitely should remove the plug completely. I'm not 100% sure, but I think the drain plug is magnetic and it will collect any shavings from the gears. If you don't remove the plug then the shavings would remain in the transfer case.

The manual does read 3.0L (3 1/8 qts.) for refill. As long as the vehicle is parked on a completely flat surface when refilling and the new fluid is level with the bottom of the drain plug opening on the case, then I think you're good.

[dapfnp]

Well when you drain the transfer case you definitely should remove the plug completely. I'm not 100% sure, but I think the drain plug is magnetic and it will collect any shavings from the gears. If you don't remove the plug then the shavings would remain in the transfer case.

The manual does read 3.0L (3 1/8 qts.) for refill. As long as the vehicle is parked on a completely flat surface when refilling and the new fluid is level with the bottom of the drain plug opening on the case, then I think you're good.

Thanks for the reply, I actually did remove the fill plug, but not before removing the drain plug. The drain plug is not magnetic like the diff plugs. Actually, the old fluid looked pretty clean to me, I was suprised.

But what I was trying to say was if I had removed the fill plug first, I might have seen some fluid drain from the fill plug until it was down to the level it seems to be now (which is the level using the old finger in the hole method). I am thinking that this was overfilled at the factory purposely, but not sure why and how, and if I should try to replace the exact amount I drained.

[Pwnin O'Brien]

I think that as long as you fill it up to the service manuals specifications then you should be ok. There's really no way to fill the transfer case over the fill plug opening unless you park on a really steep hill and fill it. I also don't see any real benefit to overfill it. I would think that it's better to not overfill it because air will dissipate the heat better than oil will and the extra oil will create more drag.

I do recommend though that you drive the car a little before draining the oil so that the oil is warm and easier to drain.

I dunno, just my two cents.

[nheitz]

It is overfilled at the factory. They squirt in the fluid with an air-pressurized dispenser & slap the drain plug back in. When you change, just fill to the bottom of the fill plug on level ground & you're good.

[dapfnp]

It is overfilled at the factory. They squirt in the fluid with an air-pressurized dispenser & slap the drain plug back in. When you change, just fill to the bottom of the fill plug on level ground & you're good.

thanks for the info, this is what i was thinking, thanks for confirming.