[SilverOLDS]

Originally Posted by base1hits

Well, I didn't post the original note on Sea Foam, but I read about it. So, I did use Sea Foam per directions on my 2000 Venture with 128k miles. The transmission was shifting hard, especially when hot. I poured in half a can, drove for several miles until hot, shifted through all gears including reverse, then drained/cleaned/changed tranny fluid and filter. The Sea Foam MAY have decreased the hard shifting somewhat but it was still not eliminated. It did, however, remove lots of gunk from the transmission when I cleaned it out. I then ordered and installed the ZZ performance shift kit to adjust the shift points from 1-2 and 2-3. This has made a major difference, and the tranny has worked well for for 3K miles now, no hard shifting even when hot. My tranny was in pretty good shape to start with, so I hope the shift kit will take care of it. I would recommend using the Sea Foam only to clean out the tranny, and then install the kit IF your tranny is still working but only with occasional hard shifts. So far so good for me.

I had the same hard shifting issues. Did exactly as above and all the hard shifting has gone. I used the Transco shift kit. The only issue is that the tranmission still has a whine to it in 1st and 2nd gears.