ChevyVanMan

Just turned 50K on my 2016 Express and believe in preventive care. I asked dealer about a price on dropping the Transmission pan and doing a filter change. They said most opt to do a flush , replace fluid nowadays unless they let it go way beyond 100k. Never had it done and just wondered if anyone else has done this ?
Thank you
Ken

mountainmanjoe

Yes. What would you like to know about it? Just do what it says in your manual.
The filter is cheap compared to all the fluid needed.

tech2

I was informed from my shop foreman....from gm engineering...if you do complete fluid changes from new following the regular maintenance schedule...you don't need to change the filter. I prefer complete fluid exchanges...why leave half the old fluid in there?
The first trans fluid service is the most important...it will remove 80% of the particles that will circulate for the life the trans...from assembly, mating of clutch packs.

mountainmanjoe

I've heard the opposite from transmission shops. Partial fluid changes are usually good enough. (unless the fluid is really old, or the transmission has been working really hard.). You will never get it all out anyway because a lot of it is hung up in the torque converter, cooler and lines, and all the nooks and valleys.

The particles will be in the filter, because that's what it's there for. Would you leave your old engine oil filter in place?

oilcanhenry

You wont get that choice with lots of the new automatics. They have the filter built into the housing. Impossible to change without disassembling the transmission case.

That said, no never have had a flush done. Just change the fluid often, and change the filter....if you can.

tech2

there is always different opinion. partial changes are ok...complete fluid changes are better.
jatco, one of the biggest suppliers of Asian trans doesn't even use a filter...a coarse mesh screen. depth filter in a trans in not as fine as an oil filter.

And yes, you will get all the fluid out of the convertor, line, cooler... the pump and convertor are what move the fluid into the exchange machine.
I've seen pan drops done and new fluid put in...next service...looks like the fluid was never changed cause it mixed with old fluid. with an exchange, it always looks new.

ChevyVanMan

Looks like a flush then as they say if you get them it is better and cheaper than dropping the pan and doing filter change and keeping a lot of the old oil in there.
Appreciate all the comments.
Thank you
Ken

tech2

Is it cheaper? what is the cost for each service? I know the labour times but not the retail costs.

mountainmanjoe

I was thinking of a pan service. Yes those exchange machines get most of it out, but you'd have to pump quite a bit to get it all.

How a fluid looks isn't a reliable indicator of condition I think. If it's dirty then it's doing it's job. Trans fluid doesn't have to deal with combustion contamination like engine oil does. It mainly needs to transmit hydraulic power which it will do for a long time before needing total replacement.

tech2

remove the trans cooler line and start the vehicle and see how fast it comes out...with the equipment, you will exchange 17 liters in under 10 minutes.
smell and colour is a very reliable indicator of trans fluid condition...if its brown and smelly it need replacement. maintaining the correct friction co-efficient for clutch pack life, detergent life are keeping the valve body clean are all reasons to change the fluid.