[Robby]

General Motors specifically recommends AGAINST a flushing process of any sort......I might add that EVERY domestic manufacturer recommends against the proceedure.

I cannot speak for the imports but wouldn't be surprised if they make the same recommendation.

If the manufacturer felt that flushing was a viable service, they would provide machines......no domestic does.
The only flushing machines available are those made by aftermarket companies and dealers that have them were sold the 'Hype'

The actual flushing is occuring in your wallet......

Your car, your call.

Rob

There is only one time a flushing process is called for and that is to flush the trans cooler after a catastrophic trans failure.....the trans is not connected to the machine for that service and actually a formal flushing machine is not required.....they just want fresh fluid hand pumped both ways through the cooler.

I added this cause I hit the save button too soon.

 

[Robby]

I wouldn't touch it. Imo. But if you feel you want to, drop the pan, make sure to change internal filter (but sure what type of filter is in this one) otherwise don't bother. Cooler line won't do anything but stir up contaminants inside the transmission. In most cases there is also a magnet on the bottom of transmission pan for metal filings and such. Those transmission flush machines do not clean the transmission the sediment will still be in the bottom of transmission. That's a direct comment from a journeyman GM tech

There is no 'pan' to drop on this trans......a drain bolt, a fill hole, and a rather huge ball screen type filter that lives within the case halves, designed to filter successfully for the life of the trans.

I often wonder if that filter, or any internal filter, is why 'flushing' is not recommended.......maybe the potental of dislodging debris that is harmlessly sitting in a corner (such as the normally sheared bits of clutch material and bits of metal) could foul the filter and present a flow restriction???

Admittedly a WAG but seems quite feasable.

Rob

 

[Robby]

Clutch steels are just that....steel....so to the roller bearings/races, the spiders, the ring, the chain, the sprockets.....you get the drift....lots of ferrous.....and a rather fair amount of shearing takes place.

As far as the process, I can only repeat the stance GM has taken.....and they don't give a breakdown of 'This process is OK and that process isn't'.

As a result, my conclusion is no flushing process that requires the assistance of any machine that must be tapped into the lubrication system of the trans is acceptable.

There was a time I did a annual fluid /filter change.....turbo 350's of the 70's, turbo 700 R4's of the eighties, 4L60's of the nineties.
This was a simple pan drop/filter change/assemble and fill service......never had a trans failure regardless of mileage.

Now, I tend to run with the manufacturer.....leave it alone.

Rob