Ok so I have another transmission question. Last night I was under the dash tying up some loose ends. Adjusted the headlight dimmer switch, removed an old aftermarket alarm and pulled the instrument cluster to fix the tac (which failed), and replaced a bunch of burned out dash bulbs. While I was under there I noticed that there was two layers of carpet. So I tried to pull the top layer back and cut out some of the bottom layer. in doing so I torqued on the gas peddle a bit. Now when I'm on the throttle even driving at a steady speed it will not go into 4th, just stays in 3rd and the shift light on dash stays on. If I let off it goes into 4th and the light goes off. I can feel it downshift back to third if I move the shifter to 3rd. As soon as I put it back into fourth it shifts into fourth, but as soon as I touch the throttle it goes back to 3rd again. Is there any adjustment to the overdrive control on the throttle and also does the break switch have anything to do with this?

 

have you checked the tv cable to make sure it wasnt knocked out of adjustment.

 

I have not but will tomorrow. Although every thing else works as should. I know there's a sensor connected to the throttle to control the shift to 4th but I don't know where it is. Been combing the internet all night trying to find info on it, If I knew what it's actually called it would help.

 

700r4 right? the throttle postion does that through the tv cable. there is a switch for converter lock on the brake switch that unlocks converter.

 

Yea that dawned on me last night laying in bed. Gonna do some checking here in a bit see what I can find.

 

The shift light in the dash is for a manual trans, the bulb isn't installed in the cluster with an automatic. It would appear you accidentally put a bulb in that place when you replaced them, which is why it's now showing up. The fix for your goofy acting light is to remove the bulb that should not be there.

 

In the wiring diagrams there is a switch called the "fourth clutch switch" that is wired to what I assume is the temperature switch for the trans. That just prevents the shift to 4th until the temp is up to operating temp correct. That makes sense on the shift light.

 

No, that temp switch controls torque converter lockup once the trans is in 4th gear only. The t.c. won't lockup until the trans reaches a certain temperature, it has nothing to do with preventing the trans from shifting into 4th. The 700R4 isn't an electronically shifted trans like it's brother the 4L60E is.

 

thats for the converter clutch lockup in 4th/od. it prevents lockup

 

Ok, I'm clear on the the switches. It's an issue with the TV or TV cable. I readjusted per factory procedure and then it would go into 4th but then I'm back to original problem of rpm flash when shifting to 3rd. Trying to find a happy place manually adjusting where both work. I may just have to pull trans and rebuild it. Or at very least put the corvett servo in to help the sloppy 2-3 shift.