transmission lockup question
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Intermediate
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transmission lockup question
85 corvette transmission blew obtain a 86 trans in the car shifts great but when im.coming to a stop car bogs down like not coming out of lockup I disconnect the lock up plug no issues a friend of.mine says its the tcc solenoid sticking but one of my other post a guy said his 86 had two wires off his lockup plug power and 4th gear switch my 85 had 3 coming off the harness power 4th and ground did the 86 vette have the the ground internally ground to trans housing and could the ground on 85 harness be messing up the ecu when to come out of lock up ?
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Almost forgot to add when lock up plug is disconnected theres no.issues no bogging ur jerking its perfect plug it back in in bogs and jerks like a manual transmission coming to a stop so im.guessing if its not the wiring most likely be the tcc solenoid thanks for the help
Race Director
Joined: Apr 2003
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From: moraga ca
If it was the lock up solenoid stuck in the closed position, it wouldn't make any difference if the connector was disconnected. Your problem is the signal going to the connector from the ecm not telling the tcc to release.
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I did not.have this issue with old tranny just started when I.put.this tranny in couple days ago anything I should look for ?
Racer
Joined: Dec 2007
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Pinched wire.
Different lock up switches.
I'd take all the lock up stuff off the old trans and put it back in the car.
In the ATSG manual theres a ton of pages on tcc wiring because it seems they changed it every year for every application. A LOT of variables (possible).....
Different lock up switches.
I'd take all the lock up stuff off the old trans and put it back in the car.
In the ATSG manual theres a ton of pages on tcc wiring because it seems they changed it every year for every application. A LOT of variables (possible).....
Thread Starter
Intermediate
Joined: Dec 2014
Posts: 40
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Pinched wire.
Different lock up switches.
I'd take all the lock up stuff off the old trans and put it back in the car.
In the ATSG manual theres a ton of pages on tcc wiring because it seems they changed it every year for every application. A LOT of variables (possible).....
Different lock up switches.
I'd take all the lock up stuff off the old trans and put it back in the car.
In the ATSG manual theres a ton of pages on tcc wiring because it seems they changed it every year for every application. A LOT of variables (possible).....
Racer
Joined: Dec 2007
Posts: 416
Likes: 3
What I used to do in universal 700R4 swaps was used a three position toggle switch. On/ Off/ Automatic. I put a pressure switch in fourth that closes when in 4th gear. This way I could switch the tcc on any time, off all the time, or automatic in 4th.
Your best bet is to see what swiches you have and wire it to lock automatically in 4th. If you have a pressure switch that grounds with pressure run a fused key on power wire to the plug, then to the to the tcc solenoid, the other side of the solenoid to the presssure switch. It will automatically lock in 4th. You can put a switch to break the power wire going in if you want.
Then you have to make sure your tcc solenoid isn't self grounding....if your pressure switch opens with pressure, or has two terminals. Any of these you have to wire it different.
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Race Director
Joined: Apr 2003
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From: moraga ca
I have always locked
Up
My converter using the overdrive switch on my console ( converted 4+3). I used the lockup as a fifth gear in the freeway. Just unlocked it when slowing down. Now at the track, I lock up the converter in 2nd or 3rd gear at wot.
Up
My converter using the overdrive switch on my console ( converted 4+3). I used the lockup as a fifth gear in the freeway. Just unlocked it when slowing down. Now at the track, I lock up the converter in 2nd or 3rd gear at wot.
Race Director
Joined: Apr 2002
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From: Anaheim CA
That was part of a thread that showed a diagram of the trans connector and wiring. I was thinking of stealing that picture but didn't. I'll look for it and see what I can find.
Found it (posted by crowz):
Last edited by Cliff Harris; Dec 29, 2014 at 01:28 AM.
Drifting
Joined: Mar 2013
Posts: 1,952
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From: Venice Cali.
I would think the brake switch(cruise /tail) unlocks the tc also I can feel it unlock when I am driving make sure it is working
Racer
Joined: Dec 2007
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The brake switch shouldn't make it lug when almost to a stop because it should have downshifted out of fourth by then. If it's not in fourth there is no pressure to the switch on the valve body.
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well I changed the.brake switch no change does in to.lock up fine just doesnt disengage with the harness unplugged theres no issues I figure the tcc solenoid is cheap proply gonna try that like I said above had no issues with lock up on old trans
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used the old trans for a core. Is there anyway that the solenoid not disengaging all the way cuz it does down shift perfect and up shift perfect when the lock up pluged in engagement is fine just that when downshift to 3rd has alittle bucking then coming to a stop acts like about to die then regains itself.with the plug unplugs those issues are not there n drives perfect just seems like its not disengaging my friend works on vette for living n he said the tcc solenoid may not be disengaging right like hanging up alittle
Racer
Joined: Dec 2007
Posts: 416
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used the old trans for a core. Is there anyway that the solenoid not disengaging all the way cuz it does down shift perfect and up shift perfect when the lock up pluged in engagement is fine just that when downshift to 3rd has alittle bucking then coming to a stop acts like about to die then regains itself.with the plug unplugs those issues are not there n drives perfect just seems like its not disengaging my friend works on vette for living n he said the tcc solenoid may not be disengaging right like hanging up alittle
I'd unplug it and use a dvom to see is the car side of the plug has a wire grounded to the chassis. Like it's pinched somewhere. Most tcc solenoids are 12 volt powered and switched by ground.
There are some valves in the trans that might be stuck also.
Thread Starter
Intermediate
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It doesn't lock up with the plug disconnected, or it shouldn't.
I'd unplug it and use a dvom to see is the car side of the plug has a wire grounded to the chassis. Like it's pinched somewhere. Most tcc solenoids are 12 volt powered and switched byground.
There are some valves in the trans that might be stuck also.
I'd unplug it and use a dvom to see is the car side of the plug has a wire grounded to the chassis. Like it's pinched somewhere. Most tcc solenoids are 12 volt powered and switched byground.
There are some valves in the trans that might be stuck also.
When its pluged in it gets stupid
Race Director
Joined: Apr 2002
Posts: 10,036
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From: Anaheim CA
My car locks the TCC over 40 MPH. I believe the unlock speed is the same, so it should unlock under 40 MPH.
You can monitor the TCC signal from the ECM by connecting a test light from terminal F of the ALDL connector to ground on pin A. The signal is "backwards" -- the light will be on when the TCC is NOT locked and will turn off when the TCC locks:
You can monitor the TCC signal from the ECM by connecting a test light from terminal F of the ALDL connector to ground on pin A. The signal is "backwards" -- the light will be on when the TCC is NOT locked and will turn off when the TCC locks: