Don, your fears are why I only used half a can. And an earlier question....I don't think I'd leave it in. Doing this a week or so before a flush would be good. It needs time to do it'* thing.

So it'* tomorrow morning now. Cold tranny at 6am, no warm-up time....it'* better, but still doing it. Time may make it better, or if I use the other half pint. I need to drain some out from the tranny cooler to make room for more first. If I do that, I'm dropping my pan and changing my filter this weekend. Need to get my hands on a new tranny pan with a drain ASAP.

So the long and short of it is that the flush a couple weekends ago helped to take 10-15% of the harshness out of it, and yesterday took another 30% or so. It'* almost 50% better, which is good for the hard snap shifts that are trying to kill my diff. I'd prefer not to frag it this year if it can be helped.

There was some benefit, but again, I don't think I'd leave this stuff in long-term. I'll get the scantool on it this evening after work and check slip in TC lockup, and see if I can tell if the shifts are delayed as well as harsh. That'll help me narrow it down some. I still suspect the vacuum modulator may be a contributor at the very least, but I need to see if my downshifts are also harsher. The modulator should affect both.

Could a HD tranny be put on a N/A engine?

No. the Tranny is electronically controlled, those gears aren't what gear you're in, it'* your highest available gear allowed by the PCM. It'* not physically hooked up through the stick.

The car isn't in 3rd in D when you're at a stand still.