91 loyale transmission

[dkbgreengo]

Just recently bought this 91 loyale for a winter car--all fluid levels fine
til one day evidently ran out of trani fluid--never showed any sign of
leak--so now, after using bars leak in transmission w/ new fluid it shifts
fine til 45--after that it doesn't want to shift but will eventually--those
rpms are getting up there--all set to take to the shop but am wondering why
it shifts fine in lower gears if the transmission is shot--want to avoid
being sold new transmission if not neccessary---anybody out there with any
ideas?---any pre-garage direction would be appreciated.

 

[johninKY]

Goof chance the vacuum modulator has a small leak and the ATF is being
sucked into the intake manifold. Just pull the vacuum line at the
modulator. Any sign of ATF means you need to replace this part. The
shifting problem also could be governor-related. Folks over at
www.usmb.net have described how to repair this component.