3 speed automatic transmission will not shift gears.

Asked by deadxbyxdawnx62 Mar 23, 2009 at 01:47 AM about the 1996 Geo Prizm 4 Dr STD Sedan

Question type: Maintenance & Repair

My girlfriend recently bought a 1996 geo prizm, we drove it about 200 miles from where we bought it to where we live.. everything worked fine. I went to autozone and bought new belts, plugs, plug wires, oil/filter/pan gasket, air filter, pcv valve, thermostat/coolant, new exhaust manifold (the one that was on there had a crack in it)trans fluid/filter kit, and a battery. First thing I did was change the tras. fluid/ filter.. or atleast thats what i had planned to do... when i got the pan off there was a bunch of jb weld on the side of the trans. and no gasket..just silicone and alot of it... they jb welded a piece of the side in.. apperantly they broke it off when taking out or putting in the motor... anyhow, i decided to replace the trans. took it out..put the other one in...everything is back together all wires hooked back up...all cables adjusted all fluids filled... went to take it for a drive... it started everything seemed good, put it into reverse, it worked fine...put it in drive and worked fine, got onto the road and it would not shift out of first... got up to almost 6000 rpms, then i stopped and too it back home and parked it...checked all fluids, adjustments etc..tryed again, and the same thing... i tryed putting it in 1st and the to second, but still wouldnt do anything..im stumped completely, please hep if you can, thank you!!!!

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Nick answered 13 years ago

When you swapped the transmission, did you remember to swap the computer? It sounds like your computer is dead and not sending the rpm signal to the transmission to make it shift. Does the trans shift manually?

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Bowlpacker answered 11 years ago

did you make sure you bought the right type of trans fluid (if you used anything but the one specified in the manual your transmission is toast). Also with transmissions they tend to be if its shifting ok don't mess with them, Even if you used the right fluid it can shock the tranny and ruin it. i was told by every mechanic i know if the transmission shifts DO NOT mess with it. usually bad things happen. Do a complete tranny flush, put new fluid and filter in and reset it. Also check the computer if its still no go the tranny is probably toast

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