Hi,
I have a 1996 xj6 4.0 and I am not very mechanically inclined so I rarely do the maintenance work on it myself. I brought it in for an oil change and the mechanic said that the transmission had more fluid in it than it should. He proceeded to tell me that I will blow seals and ruin the transmission if I leave it that way. I looked at it at home and it appears to be about a quart over full.
Questions:

Is it as detrimental as he implies? I have heard that it isnÔÇÖt good to have too much fluid but they want $150.00 to drain the transmission and refill it.

Is there a simpler way of getting the quart out ÔÇô siphon or other?

Should I not drive it until it is removed?

And, the last back and forth I keep getting, online and in personal opinions, is that changing or flushing the transmission fluid can lead to transmission trouble down the line if it hasnÔÇÖt been done on a regular basis. Since I have only had the car for a little over a year I donÔÇÖt know the history in that regard.

Thanks for your help in advance and sorry to be taking your time on what must be something that is not quite ÔÇ£forumÔÇØ level questions.

ED

Submitted by mfrank@westnet.com on Wed, 06/08/2011 - 22:11

First question is how did he measure the fluid level? Check your owners manual...if the fluid needs to be checked with the engine running, it will read high when the engine is off.

If you run with excess fluid, there's a chance it will foam and cause serious damage. But I'm inclined to think that the fluid level is fine, and your mechanic is the problem.

If the fluid is really high, the simplest and safest way to fix it is to suction it out through the dipstick tube. If you don't have access to a vacuum tank, just get a long length of small gauge clear plastic hose from home depot. Pass it down through the dipstick tube. Place a pan at ground level, lead the plastic tube to the pan. Make sure you have an extra foot or so, loop it up out of the pan. Suck until fluid reaches the level of the pan, then quickly drop the end into the pan. Fluid will drain out on it's own, stop by raising the end of the tube higher than the transmission.

Submitted by NE48-24099 on Wed, 06/08/2011 - 21:46

Ed, I've used a spare electric fuel pump to remove/replace the fluid. I simply shove a long narrow hose down the filler dipstick tube and turn on the electric fuel pump.....no mess, and you watch what you are doing. It will suck out about 1 qt / min.

Submitted by mfrank@westnet.com on Wed, 06/08/2011 - 21:43

First question is how did he measure the fluid level? Check your owners manual...if the fluid needs to be checked with the engine running, it will read high when the engine is off.

If you run with excess fluid, there's a chance it will foam and cause serious damage. But I'm inclined to think that the fluid level is fine, and your mechanic is the problem.

If the fluid is really high, the simplest and safest way to fix it is to suction it out through the dipstick tube. If you don't have access to a vacuum tank, just get a long length of small gauge clear plastic hose from home depot. Pass it down through the dipstick tube. Place a pan at ground level, lead the plastic tube to the pan. Make sure you have an extra foot or so, loop it up out of the pan. Suck until fluid reaches the level of the pan, then quickly drop the end into the pan. Fluid will drain out on it's own, stop by raising the end of the tube higher than the transmission.

Submitted by dougdwyer1@com… on Wed, 06/08/2011 - 20:21

I've inadvertantly run a trans a quart over filled for months and never knew it!

Yes, overfilling can be a bad thing but personally I don't think one quart is a problem . I'm not sure how much WOULD be a problem....it probably depends on the type of transmission in question.

If the fluid on the dipstick in frothy, that's bad, and suggests the the overfilling is enough to aerate the fluid.....which means it can't do it's job.

Of course the first sign *gross* overfilling would be fluid coming out of the breather, as Wiliiam mentioned.

Cheers
DD

Submitted by wljenkins@usa.net on Wed, 06/08/2011 - 15:20

Steve's right. I should have said that you really need to have an assistant start the car and sit in the driver's seat so you can alert them to shut the car off once enough fluid gets drained out. Draining a quart of fluid should only take five to ten seconds, those transmission pumps do pumps quite fast, take it from someone who has forgotten to reconnect transmission lines in the past and has wound up will lots of fluid on his garage floor.

Submitted by emallia@cox.net on Wed, 06/08/2011 - 14:58

Thanks for your help, Steve.

I'll have my wife sit in the car since I wouldn't know where to find the coil HT lead anyway.

If I was smarter I'd sit in the car and let my wife take the messy side :)

Thanks again,
Ed

Submitted by wljenkins@usa.net on Wed, 06/08/2011 - 14:54

Well, my guess is your transmission has been "overfilled" for quite some time so I don't see how another three days would matter. Your oil change guy may have a point but I've been working on cars for a very long time and I've never heard of a transmission blowing seals because of too much fluid in the case. That just doesn't make any sense to me. I've rebuilt General Motors automatic transmissions in my day and I've over filled a few from time to time and I've never had one fail because it had too much fluid in it. On GM automatic transmissions, there is almost always some kind of breather or overflow port on the top and my guess is there is also something similar on your transmission as well. The transmissions in the XJ40s and your X300 are virtually indestructible. I think they're a German "ZF" automatic transmission but I can't remember...

Submitted by emallia@cox.net on Wed, 06/08/2011 - 14:25

Thanks a lot William for the "less costly" way for me to solve the problem.

Can I drive it at least until the weekend before draining the fluid?

Ed

Submitted by wljenkins@usa.net on Wed, 06/08/2011 - 14:20

You can disconnect one of the transmission cooler lines on the radiator, on the tank on the left side of the radiator, start up the engine and let it pump out a quart of fluid.

I would disconnect the top one and put some kind of an extension hose on it and have it drain into a can. I believe the fluid comes from the transmission via the top line on the radiator tank and returns via the bottom line.

I do understand their $150.00 charge to drain and replace the fluid because the whole pan has to be removed from the transmission as there is no drain plug.