Th350c torque converter relay
Thread Starter
Instructor
Joined: Jan 2015
Posts: 200
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From: shreveport Louisiana
Th350c torque converter relay
Can someone please tell me where the relay is for the th350c. I am thinking its staying locked up all the time. So instead jacking up the car and throng to find where the wires go into the transmission I was hoping there was a place under the hood to just unhook it and test it out
Le Mans Master
Joined: Dec 2006
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Can someone please tell me where the relay is for the th350c. I am thinking its staying locked up all the time. So instead jacking up the car and throng to find where the wires go into the transmission I was hoping there was a place under the hood to just unhook it and test it out
1)A one pin packard style plug that you disconnect to set timing.
2)A 4 pin weatherpak plug that goes to the dizzy.
3)A 3 pin weatherpak plug that runs down to the tranny. Unplug that 3 pin jack marked ABC
Le Mans Master
Joined: Dec 2006
Posts: 8,837
Likes: 1,028
Le Mans Master
Joined: Dec 2006
Posts: 8,837
Likes: 1,028
Just inboard of that are 3 connectors just going wiring to wiring. Take that picture and post.
(Between that relay and the dizzy, just loose and hanging there).
Drifting
Joined: Aug 2009
Posts: 1,346
Likes: 160
From: new iberia la
Your TCC cannot stay locked all the time.. the engine would die when you stop ..It should only be engaged while trans is in high gear ,, watch your tach, you can see it lock and unlock by 200-300 rpm change at steady throttle in high gear at 40-45 mph
Team Owner
Joined: Jan 2006
Posts: 37,637
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From: Crossville TN
There could be a computer malfunction, a wiring fault, etc. So "things" can happen that you don't expect. Whether an 80 or an 81, there should be a relay that is fired by the L/U circuit or the ECM. If that relay has failed in the 'closed' position, it would cause a problem.
It is possible that the ECM actuates the L/U clutch directly, but it would be unusual for a computer to pass significant current that way.
I don't have an 80 or 81, so I don't own the documentation for directly answering your question.
It is possible that the ECM actuates the L/U clutch directly, but it would be unusual for a computer to pass significant current that way.
I don't have an 80 or 81, so I don't own the documentation for directly answering your question.
Last edited by 7T1vette; Dec 26, 2016 at 01:11 PM.
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Le Mans Master
Joined: Dec 2006
Posts: 8,837
Likes: 1,028
There could be a computer malfunction, a wiring fault, etc. So "things" can happen that you don't expect. Whether an 80 or an 81, there should be a relay that is fired by the L/U circuit or the ECM. If that relay has failed in the 'closed' position, it would cause a problem.
It is possible that the ECM actuates the L/U clutch directly, but it would be unusual for a computer to pass significant current that way.
I don't have an 80 or 81, so I don't own the documentation for directly answering your question.
It is possible that the ECM actuates the L/U clutch directly, but it would be unusual for a computer to pass significant current that way.
I don't have an 80 or 81, so I don't own the documentation for directly answering your question.
Thread Starter
Instructor
Joined: Jan 2015
Posts: 200
Likes: 15
From: shreveport Louisiana
Thanks for all the input. Big2bird I found the wires you were referring to and got them unplugged and that seemed to fix it for the most part. It actually broke the wheels loose for the first time and didn't seem to be sluggish like it always has lol. Now I just need to figure out w it won't shift manually. I can put it in drive and it will go through all the gears but if I put it down to first I pulls good when I shift to second the doesn't do anything but slip then when I shift to third it chirps the tires nicely. Idk
Last edited by Danny.reamer; Dec 26, 2016 at 09:24 PM.
Le Mans Master
Joined: Dec 2006
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Thanks for all the input. Big2bird I found the wires you were referring to and got them unplugged and that seemed to fix it for the most part. It actually broke the wheels loose for the first time and didn't seem to be sluggish like it always has lol. Now I just need to figure out w it won't shift manually. I can put it in drive and it will go through all the gears but if I put it down to first I pulls good when I shift to second the doesn't do anything but slip then when I shift to third it chirps the tires nicely. Idk
If your going to do that, I suggest upgrading to a 700R. It will cost you double the rebuild or more, but it's a great upgrade.
My 2 cents.
Thread Starter
Instructor
Joined: Jan 2015
Posts: 200
Likes: 15
From: shreveport Louisiana
Originally Posted by Big2Bird
Its rebuild time.
If your going to do that, I suggest upgrading to a 700R. It will cost you double the rebuild or more, but it's a great upgrade.
My 2 cents.
If your going to do that, I suggest upgrading to a 700R. It will cost you double the rebuild or more, but it's a great upgrade.
My 2 cents.
Le Mans Master
Joined: Dec 2006
Posts: 8,837
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Maybe so I'm no transmission gut but it just doesn't make any sense why it works perfectly n drive (3rd) but not manually. Why the 700? I was wanting to swap to a 200r if I have to do that because of the more direct fit but is there and better advantages to the 700?
I used a later model case, many upgraded new parts, and a hydraulic lock up kit in mine.
Bow-tie cross member, and shortened the driveshaft. Added the shiftworks shifter kit.
350C was not a very good tranny.
Le Mans Master
Joined: Dec 2007
Posts: 6,422
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From: McHenry Illinois
You should be able to unplug the connector from the side of the trans and drive it, if it doesn't go into lock up then the tcc solenoid is ok, it can fail. Not sure about the 350C, but the 2004r can get the tcc solenoid stuck and the converter will stay locked in all gears except 1st.
Team Owner
Joined: Jan 2006
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From: Crossville TN
In the one instance (in drive), the range valve is in 'drive' position and the valve body just does it's 'thing'. In the other (manual shifting), the range valve is moving through 1st, 2nd (where it just slips), and then 3rd. So, the difference is the range valve is in a different position. Also, you are moving the shift lever, so the shift cable/linkage is in a different position: drive rather than in specific range.
You should watch the action of your shift cable as it is worked through the ranges and look to see if it is a smooth action from one range to the next (and so on) or if there is some 'stop & go' type jerking as the cable is moved. It is possible that the range valve is not positioned properly in 2nd range and no signal to that clutch is sent.
P.S. So I agree with you that the 2nd range clutch should be OK, since it operates OK in automatic shift mode.
You should watch the action of your shift cable as it is worked through the ranges and look to see if it is a smooth action from one range to the next (and so on) or if there is some 'stop & go' type jerking as the cable is moved. It is possible that the range valve is not positioned properly in 2nd range and no signal to that clutch is sent.
P.S. So I agree with you that the 2nd range clutch should be OK, since it operates OK in automatic shift mode.
Last edited by 7T1vette; Dec 28, 2016 at 01:22 AM.
Thread Starter
Instructor
Joined: Jan 2015
Posts: 200
Likes: 15
From: shreveport Louisiana
Originally Posted by 7T1vette
In the one instance (in drive), the range valve is in 'drive' position and the valve body just does it's 'thing'. In the other (manual shifting), the range valve is moving through 1st, 2nd (where it just slips), and then 3rd. So, the difference is the range valve is in a different position. Also, you are moving the shift lever, so the shift cable/linkage is in a different position: drive rather than in specific range.
You should watch the action of your shift cable as it is worked through the ranges and look to see if it is a smooth action from one range to the next (and so on) or if there is some 'stop & go' type jerking as the cable is moved. It is possible that the range valve is not positioned properly in 2nd range and no signal to that clutch is sent.
P.S. So I agree with you that the 2nd range clutch should be OK, since it operates OK in automatic shift mode.
You should watch the action of your shift cable as it is worked through the ranges and look to see if it is a smooth action from one range to the next (and so on) or if there is some 'stop & go' type jerking as the cable is moved. It is possible that the range valve is not positioned properly in 2nd range and no signal to that clutch is sent.
P.S. So I agree with you that the 2nd range clutch should be OK, since it operates OK in automatic shift mode.