Flushing the transmission?

[DFrank]

I've been warned that when we drop the pan to change the oil in our auto trannies, much of it remains inside the unit. A local 4X4 shop reccomended a flushing process to get all of the gunk out. They charge $150 or so for this.



Would this be of much benefit? Is there a way for the average wrencher to get more of the residual fluid out when changing the ATF?



Also I think dodge reccomends service at 30K. This seems like a good one to do early; when have others been servicing?



Thanks, Dave.

 

[stacerbob]

Redneck Flush

Change fluid & filter as usual.

Have 2 empty buckets, fill one with how much fluid you want to flush through (2 gal) Disconnect cooler line, extend them discharge into empty, return in the clean new fluid. Start, when the empty one gets full, all the new should be in the transmission, for the most part, button it back up and top off the fluid.

 

[Ken F]

How can I determine which transmission line feeds the cooler and which one goes back to the transmission?



Ken.

 

[Rosco]

I wonder if all of those transmission shops and the like that are advertising these "transmission flush service" are using ATF+4 fluid? I highly doubt it, so unless you have this service done by a Dodge dealer you most likely will get ATF+3 which is not approved for our rig's.

 

[Fireman Dave]

I just drop my pan and drain it and change the filter. I change it often enough (once a year - about 12,000 miles), that I figure it cycles out on it's own pretty well. It's always been nice and clean when it comes out, so my system seems to be working fine. I've read on here before that the flush can actually stir up crap and cause trouble.

 

[ttreibel]

I also like the drain and fill what you can method, I don't have an auto on my truck to do this but I apply this to the anti-freeze.

 

[R.M.THOMPSON]

Been advised not to allow a flush at a shop due to unknown fluid types finding there way into our trannys. Frequent changes will keep contaminants diluted .

 

[RobertBolinger]

Originally posted by Ken F

How can I determine which transmission line feeds the cooler and which one goes back to the transmission?



Ken.

When I installed a trans cooler on another vehicle the instructions said to start up vehicle from cold-put in drive for 30 seconds, and then shut off-slightly hotter line is from transmission.