Transmission Fluid Change question

[RStocker1]

I have a 1998 XLS which needs a trans fluid change. Opening up the plug on the pan drained out less than 3 qt, and the book says the capacity is 5.8 qt. I'd like to change out as much fluid as possible without dropping the pan/changing gasket (since I've seen other posts warning about problems after doing that). My question is this: Would starting the engine after draining the the pan (and replacing the plug) pump more fluid out of the converter and cooler into the pan so it could be drained as well? And, more importantly, would this create problems by running the system with about half the fluid it normally needs for a few minutes?

[sickwilly]

yes, it will move more fluid out and YES it can create problems.

The solution is to get extra fluid, drain and fill, bolt it up, run the car till warm, drain and fill, and repeat as many times as you like. Three should be sufficient to replace most of the fluid.

The other solution some people do is to remove one of the tranny oil cooler lines from the radiator, run the car, drain from this tube, and keep adding till the fluid runs clear. This way the fluid never gets too low. Too much potential for a mess up for me. I prefer the drain, fill, and repeat.

My 97 also has a one quart differential to drain and fill to while you are under there. Not sure if yours is seperate or connected. This does not have to be repeatedly drained, you will get all the fluid with one drain.

[RStocker1]

Originally Posted by sickwilly

My 97 also has a one quart differential to drain and fill to while you are under there. Not sure if yours is seperate or connected. This does not have to be repeatedly drained, you will get all the fluid with one drain.

Yes, the 98 has the same separate differential chamber. I have a different problem there because that drain plug is so close to the engine subframe I'm having trouble with the 10mm hex socket on the wrench inserted to remove the plug. I can get it inserted and barely loose, but then the head of the wrench is butted against the subframe and won't move any further out, nor allow removal of the wrench/socket. I either need to cut off about half of the 10mm hex key (which so far seems impossible with just a hack saw), or get a 10mm L-shaped hex wrench and a hammer (which doesn't lend itself to getting it properly torqued after the drain/refill is done. Any other suggestions there would also be appreciated.

[sickwilly]

bust it loose with your current wrench/hex socket, but only turn it about a haft turn or so. Then use the L shaled allen, or one of those allen wrenches that are are rounded off to allow their use at an angle, to loosen it.

I am fortunate, my local oil change place drains and refills both the tranny and differential for $26.95-- not seperate charge for the differential. I just don't get to pick my fluids.