Transmission Trouble

elboberino · July 19, 2005

Ok, so I've been having trouble with my transmission. I took it to a shop in Phoenix, a guy who my mechanic has been using for 20 years, he trusts him and says he won't rip me off. Anyways, its back at their shop for the second time in 2 weeks. The guy said they finally figured out what was wrong with my transmission. He said the FORCE MOTOR was bad. Now, I don't know squat about a transmission, an engine yes, but a transmission, not a darn thing. So is there really a thing as a force motor or should i pick up some extra blinker fluid and some new muffler bearings when I go get my truck later tonight?

Bish · July 19, 2005

Ok, so I've been having trouble with my transmission. I took it to a shop in Phoenix, a guy who my mechanic has been using for 20 years, he trusts him and says he won't rip me off. Anyways, its back at their shop for the second time in 2 weeks. The guy said they finally figured out what was wrong with my transmission. He said the FORCE MOTOR was bad. Now, I don't know squat about a transmission, an engine yes, but a transmission, not a darn thing. So is there really a thing as a force motor or should i pick up some extra blinker fluid and some new muffler bearings when I go get my truck later tonight?

<{POST_SNAPBACK}>

I believe the Force Motor is a solenoid that controls line pressure.

HERE is some info on it.

shaink · July 21, 2005

Actually I just went through this. Let me guess is your tranny shifting hard slamming into 2nd? Well I had a brand new transmission put in 10,000 miles ago and it started doing this. Took the truck to the dealer and they said this is wht it was. So they channged it and it was fine for 2 days then "CLUNK" it's doing it again. Now it seems to be doing something else screwy, if it clunks the ALT. gauge goes up to about 18 volts then back down to 10 or so. So back to the dealer and now he says its a bad Alternator that is sending to much voltage to the Force motor or Solenoid and causing it to send full pressure to the lines and hence "CLUNK" so $240 Alternator later it's not doing it anymore but it's only been 2 days.

asepgrad98 · July 21, 2005

decribe the symptoms and mabye someone can internet diagnois it for ya thats what were here for

PELICAN · July 22, 2005

Actually I just went through this. Let me guess is your tranny shifting hard slamming into 2nd? Well I had a brand new transmission put in 10,000 miles ago and it started doing this. Took the truck to the dealer and they said this is wht it was. So they channged it and it was fine for 2 days then "CLUNK" it's doing it again. Now it seems to be doing something else screwy, if it clunks the ALT. gauge goes up to about 18 volts then back down to 10 or so. So back to the dealer and now he says its a bad Alternator that is sending to much voltage to the Force motor or Solenoid and causing it to send full pressure to the lines and hence "CLUNK" so $240 Alternator later it's not doing it anymore but it's only been 2 days.

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My truck is starting to shift really hard here lately. Should I have mechanic check the alternator or force motor first?

elboberino · July 22, 2005

I should have responded earlier but work has had me busy and I just come home and crash...

I got my truck back, $125 for the Force Motor. It's a tiny little sucker, looks a little like the solenoids in the tranny (had new ones put in as well, replacing the 2 day old ones for free!) From what I understand from the mechanic, the force motor gets the signal from the gas pedal about how much pressure your foot is applying to it. When it goes bad, as mine did, you can push in the gas pedal as hard as you want but the force motor doesn't realize this so it tells the tranny or something else that your foot is barely pushing the pedal. I know its more complicated than that but with the computers these trucks have now-a-days, its hard to understand it all.

The first symptoms I had were my shifts from 1 to 2 and 2 to 3 were really hard and the car seemed to want to try to shift but couldn't the first time so it would try again and get it the second time. It happened almost all the time no matter how much I was accelerating. Down-shifting was no problem. That turned out to be a bad spring that connected something to some valves or something. I don't know anything about it but the mechanic put in a spring from a "shift kit" and before the force motor went crazy, shifting was great. Then the force motor went bad, or had been bad this whole time. I believe this also caused the solenoids to go bad. The problem I had was that the computer was not having this code come up on the computer so the mechanic had to trace the problem. The force motor even properly ohmed out but upon further inspection of it, they determined it was bad. Anyways, it didn't cost as much as I thought it would and it saved me the cost of a bad transmission ($3K rebuilt). I am happy.

I'd say, find a good transmission shop or someone who knows what they are doing and knows the GM tranny and take it to them, the problem could be as simple as a $25 solenoid.

Good luck finding out what happened.!