My automatic transmission in my 91 chevy astro was shifting funny intmittently (shifting too late, or wouldn't shift into highest gear). Some times it would shift ok almost all day, sometimes it wouldn't shift ok at all for a few days. Then my alt. started squeling and after a few days it froze up. I replaced the alt., and now the transmission shifts perfectly. It has now been a month and it hasn't shifted poorly once. When it started shifting funny, I checked it and it was low, but only a little. Could a new (good) alt. have fixed the shiting problem, or is it a coincidence?
TIA
PS I always award BA points.
2006-09-29 15:26:54 · 8 answers · asked by Anonymous in Cars & Transportation ➔ Maintenance & Repairs
Yes but if the power coming out of the alt was screwy (fluctuating, bad noise) couldn't that screw with the ecu and cause it to shift funny?
2006-09-29 15:36:07 · update #1
Many times if the battery is really low, the electronic transmission controls don't get enough voltage and send either NO signal or the wrong signal.
It is possible that caused it.
2006-09-29 15:34:57 · answer #1 · answered by Anonymous · 1⤊ 0⤋
An auto. transmission used to use a vaccum modulator that assited it to shift smoothly. but now if a modulator is used at all it would be electric. If an alternator is putting out less than 14.5 volts You are not maintaining a corrert charge for the system and components will not work. In other words you have solved your own problem...
2006-09-29 15:52:41 · answer #2 · answered by George L 2 · 2⤊ 0⤋
Yes, A voltage spike and or low voltage can cause the transmission to shift funny by causing the shift solenoid to apply too much or not enough pressure.
2006-09-29 15:35:01 · answer #3 · answered by Josh S 7 · 3⤊ 0⤋
If your tranny has sensors and electronic shifting, I suppose a fluctuatiion in elecrical current may send mixed signals to the transmission and make it act up the way it did---- I dunno. I DO know that running low on fluid can cause a tranny to do all the things you described even if it was only a little bit low on fluid. I'd have to say that replacing the alt. and fixing the tranny was an amusing and convenient co-inky-dink!!
2006-09-29 15:48:07 · answer #4 · answered by Dave Roaddogg 2 · 0⤊ 2⤋
i dont think the alternator has anything to do with transmissions...
the alternator powers the electrical in your vehicle
the trans problem most likely was from low fluid...or the ECU being reset usally fixes problems too..
2006-09-29 15:33:02 · answer #5 · answered by mommy2savannah51405 6 · 0⤊ 6⤋
the answer to your qestion is no...the alternator only runs the electrical part of your car and has nothing to do with your transmission...your transmission problems are probably due to low fluid or a bad/clogged filter in the transmission...
2006-09-29 15:32:41 · answer #6 · answered by Kenneth S 5 · 0⤊ 3⤋
no.the alternator has nothing to do with your transmission.try checking you modulater valve on the trans and the vacuum line running to it.It should be on the right side of your transmission and is a fairly cheap part.good luck
2006-09-29 15:38:45 · answer #7 · answered by bill b 5 · 0⤊ 3⤋
yes it can very well have an effect. why that 4L60E or 80E is electronic. if weak alternator, it may be it.
2006-09-29 15:35:42 · answer #8 · answered by topfueltech 2 · 3⤊ 0⤋