Be very careful when getting your transmission serviced by anyone. I have recently found out why my gc trans failed and i'm not at all happy about this. There's a rubber check ball in the cooler lines to prevent drainback from the cooler. well what i found out is when you take the thing in to get the trans flushed shops often put in additives that swell seals and gaskets which are also made of rubber. This also causes the check ball to swell and prevent flow too the cooler which sends the trans temps sky high especially at speeds going up inclines. Anyhow i'm replacing my trans this weekend and putting a brass check ball in it so i don't have to worry about this anymore.

frankley , i never trusted the trans flush by machine , friends car trans died within a few blocks after having it done , better to do it the old fasioned way , drop the pan , change the filter /gasket , refill, messy , but SAFE

I'm about to tap the tranny pan to add a drain plug and do the ATF+4 upgrade. Start by changing the filter and fluid, then drain and fill every 50 miles until it cycles 4 times to get all the old fluid out. At $5.20 a qt, that comes out about 1/3 the price of a flush and my filter actually gets changed and I know it gets done right.