Looks like torque converter. I flushed it with wall mart tranny fluid after my bog hole experience few months ago. Then filled it with Valvoline/1 gal. high mileage Dex/Merc automatic transmission fluid. The synthetic version. Shudder Starts about 1500 1600 RPM's in 3rd gear or higher. If you gas it and downshifts to 2000+ RPM it stops shuddering.

Kinda sucks cruising in traffic cause that is the sweet spot just following traffic. If I gas it run up on car in front if I let off the gas guys behind gets pissed for loosing ground.

Any hope or miracle cure out there? Read the Tech Doc on SPIII tranny fluid. The valvoline syn stuff meets that spec. Would have went with the diamond high price stuff, but would had to order and wait for it.

I did all the fluid changing, but no filter change. Guess the pan has to drop for that one and there are a couple impossible bolts to get out without dropping the support arm which is a two man job looks like.