08 Oct 07 11:22, mark lewis wrote to all:

 ml> my '95 Gran Prix has started to get a "slip" in it after
some time of
 ml> driving... in the past, i'd been told that there's no overdrive on my
 ml> vehicle but that it was using a "lock-up torque convertor" which
 ml> supposedly locks to the shaft to give a 1:1 turning ration once
 ml> cruising speed was reached...

Your car should have the 4T60-overdrive tranny in it. That's the front
wheel drive 4spd version of the 4L60, aka 700R4 overdrive. L means
longitudal drive (i.e. rear wheel), T means transverse drive. Final (4th
gear) drive ratio should be in the .7:1 range.

 ml> the symptom is that while cruising, you'll feel it
"shift"... almost
 ml> a "bounce"... if you watch the tachometer, you'll see it
go from 2000
 ml> and slide easily up to 2500 and then a few seconds later, you'd feel
 ml> that "shift" again and it'll drop back to 2000... it'll
do this a few
 ml> times and then generally settles out and operates normally...
 ml> sometimes i mash on it and force passing gear for a few seconds and
 ml> then back off of it... that seems to work, too...

Ever have that tranny serviced? What locks up the torque converter is an
electronic solinoid. If your foot is too far into the gas while the engine
control modules are sensing a need for more rpm, it'll do that. There's
also an adjustment at the throttle body for the TV cable. Unlike the
earlier hydromatics, this one uses that cable to apply pressure to the
internal clutches. Out of adjustment means you could burn out the tranny.
I suspect yours is just getting up there in age. Have it serviced by a
trusted mechanic and tell them to adjust the TV cable while they're at it.

 ml> so, i dunno... is there a lock-up torque convertor on this vehicle?

Definately.

 ml> what would cause it to unlock during normal cruising (~60mph)? could
 ml> it be something as simple as fluids? i've checked them by the owner's
 ml> manual and they seem to be fine :?

Service it.

                R\%/itt


"Mass Dinosaur Distinction?! The real truth is: Reptile Dysfunction!..."

--- Twit(t) Filter v2.1 (C) 2000