transmission question
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transmission question
Hello all I have a question about my 97 f350's auto tranny. I'm not sure what transmission is in it but it has over drive. I bought it used and the tranny slides into gear when it shifts. When it makes the 2 to 3 shift always at 35 it slams like its going into gear. I believe it is the torque convert locking up because the rpm's go way down when it slams in like that under moderate accleration and its like a extra shift before going into overdrive. I've been doing some searching and I think a new torque converter would cure it because the Od light dosen't flash like anything is wrong. Is a transmission rebuild in order? Or I maybe wrong. What is a good replacement torque converter? Any advice and help would be greatly appreciated!
Transmission Rebuilder
Joined: Jul 2008
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From: North Georgia
If lock up is coming on and holding I would say the torque converter is doing its job. It sounds like you have a control issue, It would be helpful to know it the computer has applied the converter clutch or if it is coming on when not commanded. This will tell you if you need to look at the tranny or the computer and its information. A scanner with data stream would be what you need to do this.
Things to try, drive the truck with the brakes barely applied (just enough to turn on the brake lights), if the symptom is gone I would look for a control problem outside of the trans.
If it still has is problem then I would look at the valve body especially the solenoid block. Could also have a problem in the pump, that is where the lock up valves are.
Things to try, drive the truck with the brakes barely applied (just enough to turn on the brake lights), if the symptom is gone I would look for a control problem outside of the trans.
If it still has is problem then I would look at the valve body especially the solenoid block. Could also have a problem in the pump, that is where the lock up valves are.
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Sweet thanks for the reply. I'll try the brake trick today and see what happens. I forgot to mention I've changed the filters and oil and put in a bully dog shift enhancer and it did firm up the shift a bit but it still slams like I said. Which valve body has the solenoid block in it? Thanks again!
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It did it before I put in the shift enhancers and changed the fluid and filters. The shift enhancers were just 3 springs and a replacement valve piece in the front most valve body. I think it locks up harder with the shift enhancers in. Thanks in advance!
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I drove it a few hundred miles pulling a trailer with quads on it and on the freeway in overdrive it would feel like its slipping under heavy acceleration. But usually only on steep grades. Any ideas would be great.
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Hello again I tried holding the brake and accelerating threw the gears and it still locked up pretty hard. But I did have a small trailer hooked up to the truck. Will try soon without any weight in or on the truck. Thanks
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Frmr Ford Trans Engr
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From: SE Florida
There are four solenoids. One is the pressure control solenoid, it controls line pressure in the trans. Another solenoid turns the torque converter clutch on or off. Two others shift each forward gear in the trans.
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I tried the brake trick and when it got to 35 mph it revved up from about 1500 rpm to 2000 rpm then back to 1500 rpm it did this cycle about 3 times til I let off of the gas and brake pedal. Is this the torque converter locking and unlocking? If so what does this mean a control issue? I seen another post where a guy hooked up a switch to manually lock the converter when needed. If I have to i'll do this but is there any other way to fix this? Switching this on and off sounds like a real pain and I know me i'd frequently forget to switch it on and off. Any help would be appreciated!
