Well, I swear, I have through gallons of both due to leaks and failures on my two Olds powered vehicles. I even replaced the usual seals that fail on both transmissions. Torque converter seal, rear housing plus a bushing in the TH350. Plus pan gaskets and new filters. This time I used regular Dexron 3 in the TH2004R and Type F in the TH350 to help with leak issues. All seemed fine on the 2004R, it now either leaking at the front seal or the front of the pan. I may have the torque converter pulled too far forward, aftermarket replacement. The TH350 pan looks to have seepage or from the dipstick tube, reverse light switch or all of the above. It actually shifts pretty soft with the Type F compred to what it did, should be the other way around. All these GM trans seem to leak from somewhere and fail easily. Were Dodge and Ford as bad? Pretty sure the 904 and 727 were really good in the day.

 

I would reply re: leaks but I don't want to jinx myself

 

Just venting. The TH350 went from shifting shift kit firm to OK and doesn't seem to shift down into first at a stop. Unless I manually shift to first, won't spin the tires otherwise. It could be the $70 to replace gas pedal kick down cable that came apart and may be sticking. I went with Type F to help with leaks and firm up the shifts, it did neither. I am hoping adding washers will fix the 2004R leak by pushing the converter back. I even had to add 2 washers between stock TH350 converter and flex plate.