Hi all.

Working on my sons 80 volare slant 6, 904 automatic.

It is shifting funny from 2nd to 3rd....hard to describe....sort of a slip but not really...revs thru first into second ok....revs up to 3rd and shifts, but then "slips" back to 2nd briefly then grabs 3rd again.....kind of like a delayed soft shift.

As some may recall, we had pulled the engine for a rebuild....noticed no issues prior...had the shop redo the oil pan gasket with the engine in the car due to a subsequent oil leak, but to do so they had to jack the driver side of the engine up.....they did have tow tweak the trans lines a bit to do so but other than that, I saw no major issues.....

It's likely just chance.....the car is high mileage and likely all original so....

We have only had the car since summer and much of that was downtime due to the rebuild. But it shifed fine before.

We did do a super 6 conversion which meant switching to the bouchillon kickdown cable setup. We think it's setup right.

Maybe all those extra ponies with the Super 6 upgrade is too much for the trans...LOL.. JUST KIDDING.

No history on the trans. We have not done a fluid change yet, and I am hesitant to do so since we dont know if it has ever been done before and if so when.......the fluid looks/smells ok...not burnt.....

Could this be a simple fluid swap and band adjust or does it bode a full rebuild given you guys' experience with the 904?

Start with dropping the trans pan & changing the filter & fluid.

You will get a chance to inspect what is inside & you can adjust the bands & main line pressure, while the pan is off.
DD