Torque Converter Drain & Proper Transmission Refill Level

[EROD]

We have a pre-owned 2009 CX-9 GT FWD that we purchased from previous owner at 70K miles on it (mostly highway miles as she traveled between Dallas and Corpus Christi almost on a monthly basis for 4 years....plus it's still on it's original brake pads which lends credence to her claim). It is now at 80K. Previous owner stated she never had the transmission fluid changed and I would like to get it done now (better late than never?). I think a flush would probably not be recommended at this stage. Not sure which side to believe: the one that claims high-mileage flushes (when no routine flushes were done previously) will loosen up debris that will cause problems or the one that claims nothing bad happens. In any case, since neither side can totally convince me, I will err on the side of not risking it and will instead just do a drain and refill with filter change, which seems to have a consensus agreement that nothing bad will come of it. Now having said that, I know the majority of the fluid is in the torque converter and I really don't want to do the multiple drain and refills to dilute the old fluid if at all possible. That will never get all the old dirty fluid out, is wasteful, and I certainly don't want to be under the darn thing all day long. So...has anyone found a way to drain the torque converter? I've always owned RWD cars where the transmission and differential are two separate units which made for real easy access to the torque converter and it's drain plug. Since this is a FWD and has a transaxle, does this eliminate access to the torque converter? Finally, at what temperature should the fluid level be checked? I've got an infrared thermometer I've used on all my other cars to take the temp at the pan to determine when to check the level and it's always gotten me to within a couple of ounces of what the OEM spec called for.

 

[sts7049]

i don't believe in transmission flushes. drain and refill only. better to do that twice in my mind than take the risk of stirring stuff up.

 

[Bgallodoro24]

I did mine three times using 9 quarts of T-IV

 

[cpb406]

According to the service manual for the 2012 there is a cover to gain access to the torque converter to flywheels mounting hardware. There is no mention of a drain plug for the torque converter but it might be worth a look.

 

[brandini]

The torque convertor itself is the pump for the 'flush', it's more accurately a fluid exchange. A machine is attached that keeps the fluid leaving and fluid entering the transmission balanced so you don't suck in air.

A flush before 75k should be fine, but at higher mileage I'd do 1 drain and fill, wait ~10k miles, and then flush since the new fluid will help suspend contaminants and counteract any acids that have built up. You want to do this gradually the older the car is.

Otherwise a first flush at 30k will go a long way to removing break-in wear particles. Subsequent flushes will depend on the quality of the fluid you use, or you can take the guesswork out and get fluid analysis done for ~ $30 to determine future change intervals.

The drain and fill frequently method should be followed to keep the 'oldest' fluid from reaching the standard 'full flush' mileage. For example if a 12 quart transmission drains 3 quarts and a flush is due every 60k you'd be draining and filling every 15k miles or every 3rd oil change. This method would not completely remove all break in wear like a flush would, so starting this process after a 15-30k break in period with no changes, a flush, and then doing 15k D&F intervals would be a great compromise between the labor cost of a flush and keeping the newest possible fluid in the car.