changing transmission fluid

[marvin]

i have been hearing that flushing your tranny is not the way to go. people have told me that just changing the fluid and filter is better. can someone please let me know which is better.

[fastblackmerc]

i have been hearing that flushing your tranny is not the way to go. people have told me that just changing the fluid and filter is better. can someone please let me know which is better.

If you just change the filter and replace the fluid that drips out you'll never replace all the fluid. The torque converter doesn't have a drain plug and you won't get any fluid out of the cooler.

You can change the fluid your self but it's a messy job.

This is what I'd do if the tranny has never been serviced.


Take off the pan and replace the filter
Replace any fluid lost
Drive to a place that power flushes the tranny
Get the tranny power flushed

[BlueFusion]

If the fluid isn't dirty, just do it at home by dropping the pan. If you want to get even more out, pull the valve body (a great time to do the J-mod, too). You will not get what's in the torque converter or cooler, but you will get about 8 quarts of fluid out which is a pretty good amount for cheap.

[RF Overlord]

marvin, if the transmission in your car has been serviced at intervals appropriate to the driving conditions since new, then simply doing a pan-drop and filter change every 30,000 miles is adequate. If not, or if you bought the car used and have no maintenance history, then doing a complete fluid exchange (not a "power flush") would be advisable. This can either by done by a shop with the right equipment, like a T-Tech machine, or you can DIY by disconnecting the line going TO the cooler, and letting the fluid pump into a bucket while replenishing the fluid through the dipstick tube. Either method works equally well.

[JimmyXR7]

marvin, if the transmission in your car has been serviced at intervals appropriate to the driving conditions since new, then simply doing a pan-drop and filter change every 30,000 miles is adequate. If not, or if you bought the car used and have no maintenance history, then doing a complete fluid exchange (not a "power flush") would be advisable. This can either by done by a shop with the right equipment, like a T-Tech machine, or you can DIY by disconnecting the line going TO the cooler, and letting the fluid pump into a bucket while replenishing the fluid through the dipstick tube. Either method works equally well.

Included in the trans pan drop would be to clean the magnet so it works as new.
Some techs recommend to do the pan drop one service and the flush the next time. and then repeat.
One member here did not know the history of his MM, so he did both. Remember $150 for a flush or pan drop is a lot cheaper than $1500+ for a rebuilt transmission with the extended down time.
Do a search for my post with the photo of the magnet in the trans pan for more info.
Jim

[musclemerc]

Read this thread, post #9
http://www.mercurymarauder.net/forums/showthread.php?t=63712&highlight=transmission+fluid

[RF Overlord]

i have been hearing that flushing your tranny is not the way to go.*sigh* ...that old myth again.

Not only is there nothing wrong with doing a complete fluid exchange, it's the method recommended in the factory service manual.

The one caveat: if the fluid is brown, burnt, and smelly, you may already have enough damage that changing the fluid will be a case of too little too late, but rest assured that if the transmission fails at that point it's because of neglect/abuse, not because you did a flush.

/soapbox

Having said all that, if the transmission has been serviced at intervals appropriate for the type of use, then doing a pan-drop will be adequate. If the transmission has not been properly serviced or has an unknown maintenance history, do a fluid exchange and install a new filter now, then simple pan-drops will be all that is required in future.