TH350 Torque Converter Lockup
Drifting
Joined: Feb 2002
Posts: 1,987
Likes: 3
From: Manchester, Dead Center in the Middle of TN 25 miles to Jack Daniels,10 miles to Geo Dickle, and .8 mile from the Liquor Store at I-24 Exit 114
St. Jude Donor '05
Re: TH350 Torque Converter Lockup (UKPaul)
Sounds good to me UK, I just didn't realize my lock up style was one year only.
This may be relative to the subject or not. I had an '81 one time to work on for a friend. The '81 has a "Computer" (if you can call it that) operated Distributor and with the "Electric Q-jet".It is a quite primitive system compared to todays systems.
If I remember correctly the "Computer" was actually a board that operated the dist. & carb. I was looking for a board to replace the one in this car and checked my friends Hollander Interchange book and the board was the same as a Chevette and several others. If anyone needs to know for sure I can reference this book for you.
It is amazing what parts interchange from other vehicles with a Corvette. Some years ago I had a '66 coupe. I think the arm rest on it was the same as the rear door armrest on a '62 - '64 rear four door Chev. Impala. JIM
This may be relative to the subject or not. I had an '81 one time to work on for a friend. The '81 has a "Computer" (if you can call it that) operated Distributor and with the "Electric Q-jet".It is a quite primitive system compared to todays systems.
If I remember correctly the "Computer" was actually a board that operated the dist. & carb. I was looking for a board to replace the one in this car and checked my friends Hollander Interchange book and the board was the same as a Chevette and several others. If anyone needs to know for sure I can reference this book for you.
It is amazing what parts interchange from other vehicles with a Corvette. Some years ago I had a '66 coupe. I think the arm rest on it was the same as the rear door armrest on a '62 - '64 rear four door Chev. Impala. JIM
Thread Starter
Pro
Joined: Aug 2000
Posts: 573
Likes: 0
From: Alpharetta GA
Re: TH350 Torque Converter Lockup (ksems)
Thanks all for the replies.
I hope to be able to get on this tonight as I will be going out of town this weekend.
Sure would like to start troubleshooting this problem.
Kevin
I hope to be able to get on this tonight as I will be going out of town this weekend.
Sure would like to start troubleshooting this problem.
Kevin
Le Mans Master
Joined: Nov 1999
Posts: 5,768
Likes: 3
From: San Diego CA
Re: TH350 Torque Converter Lockup (ksems)
Also if I remember correctly, the early lock up autos had a bad habit of locking and unlocking continuously at certain speeds - this was common and to be expected. especially on early 700r4's which used to hunt for gears all the time.
anyway - hope everything above has helped - let us know.
anyway - hope everything above has helped - let us know.
Racer
Joined: Apr 2000
Posts: 499
Likes: 0
From: Kristiansand
Re: TH350 Torque Converter Lockup (ksems)
UKPaul: In the 1980 TH350C there is a switch in series with the lockup solenoid inside the transmission. This is controlled by govenor pressure and close at a certain speed. If this switch is bad you wont get lockup.
Have you tried to feed 12V directly to the transmission (green wire at my 1980)? This will verify if the problem is inside the TH350 or not.
Have you tried to feed 12V directly to the transmission (green wire at my 1980)? This will verify if the problem is inside the TH350 or not.
Safety Car
Joined: May 2001
Posts: 3,758
Likes: 3
From: Surrey
Re: TH350 Torque Converter Lockup (Ingar, Norway)
Hi Ingar,
Thanks for the reply. Mine is an '81 - will it still have the switch? I've tried feeding 12V directly into the g/box connector & grounding the other terminal but it still didn't lock up. Once I've finished putting the engine back together I'll drop the trans pan & have a look.
Do you get good views of the Aurora Borealis (SP?) where you are?
Paul
Thanks for the reply. Mine is an '81 - will it still have the switch? I've tried feeding 12V directly into the g/box connector & grounding the other terminal but it still didn't lock up. Once I've finished putting the engine back together I'll drop the trans pan & have a look.
Do you get good views of the Aurora Borealis (SP?) where you are?
Paul
Racer
Joined: Apr 2000
Posts: 499
Likes: 0
From: Kristiansand
Re: TH350 Torque Converter Lockup (ksems)
UKPaul:
If you have two wires going to the transmission, then its different from the 1980.
As seen on the shop manual drawing it has only one wire (12v) and the switch grounds the signal when govenor pressure is high enough.
I'm still pretty sure your transmission has a switch.
What I learned from installing the 700r4 is that GM uses lots of different lockup wirings, for the 700r4 there are at least 15 different configurations. But nearly all of them use a switch to control lockup.
The easiest way might be as you say to drop the pan, then you can test the solenoid and switch also. NO switches closes at ca 10psi, NC switches opens at ca 5psi.
You have to be in the norther part of Norway to see Aurora Borealis, or northern light as we call it here, I'm in Kristiansand.
But I used to work up north before, and it's really a wonderful phenomena.
It can occasionally bee seen in the Oslo area, but not as strong as up north.
[Modified by Ingar, Norway, 11:50 AM 3/13/2002]
If you have two wires going to the transmission, then its different from the 1980.
As seen on the shop manual drawing it has only one wire (12v) and the switch grounds the signal when govenor pressure is high enough.
I'm still pretty sure your transmission has a switch.
What I learned from installing the 700r4 is that GM uses lots of different lockup wirings, for the 700r4 there are at least 15 different configurations. But nearly all of them use a switch to control lockup.
The easiest way might be as you say to drop the pan, then you can test the solenoid and switch also. NO switches closes at ca 10psi, NC switches opens at ca 5psi.
You have to be in the norther part of Norway to see Aurora Borealis, or northern light as we call it here, I'm in Kristiansand.
But I used to work up north before, and it's really a wonderful phenomena.
It can occasionally bee seen in the Oslo area, but not as strong as up north.
[Modified by Ingar, Norway, 11:50 AM 3/13/2002]
Thread Starter
Pro
Joined: Aug 2000
Posts: 573
Likes: 0
From: Alpharetta GA
Re: TH350 TC Lockup - UPDATED ! (ksems)
Hi all,
I went ahead and pulled the electrical connection for the Torque Convertor and drove around. The car is finally running correctly. The shifting smooth and
strong and no more pinging overload sound from my engine
yeee haaww.....
now I have to figure out why this plug isnt working.....
I took my car and got the emissions test done - it failed the NOX level ...I got a 2903 and only 1047 is allowed
Please tell me this isnt related.
Thanks
Kevin
[Modified by ksems, 2:15 PM 3/14/2002]
I went ahead and pulled the electrical connection for the Torque Convertor and drove around. The car is finally running correctly. The shifting smooth and
strong and no more pinging overload sound from my engine
yeee haaww.....
now I have to figure out why this plug isnt working.....
I took my car and got the emissions test done - it failed the NOX level ...I got a 2903 and only 1047 is allowed
Please tell me this isnt related.
Thanks
Kevin
[Modified by ksems, 2:15 PM 3/14/2002]
Heel & Toe
Joined: Jul 2013
Posts: 24
Likes: 0
Recently joined, seems like a lot of knowledge on this forum...
And I hope someone can help me.
I have a 1980 , stock 350. Idles great revs even nicer, but when I put it in gear (turbo 350) it just dies, in both fwd and reverse.
A friend of mine told me it may be that my converter is locked????
Any suggestions???
Would unpluging or change the lockup solenoid help?
Update 7-20-13
Unplugged the only wire I could see, on driver's side just behind shifter assy, no luck same problem... shuts off when I put it in drive or reverse...
Any suggestions?
Do I need to pull the tranny and take it to a shop?
And I hope someone can help me.
I have a 1980 , stock 350. Idles great revs even nicer, but when I put it in gear (turbo 350) it just dies, in both fwd and reverse.
A friend of mine told me it may be that my converter is locked????
Any suggestions???
Would unpluging or change the lockup solenoid help?
Update 7-20-13
Unplugged the only wire I could see, on driver's side just behind shifter assy, no luck same problem... shuts off when I put it in drive or reverse...
Any suggestions?
Do I need to pull the tranny and take it to a shop?
Last edited by Ray384; Jul 20, 2013 at 02:02 PM. Reason: Continuing to seek help
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Melting Slicks
Joined: Oct 2006
Posts: 2,193
Likes: 156
From: Navarre FL
Recently joined, seems like a lot of knowledge on this forum...
And I hope someone can help me.
I have a 1980 , stock 350. Idles great revs even nicer, but when I put it in gear (turbo 350) it just dies, in both fwd and reverse.
A friend of mine told me it may be that my converter is locked????
Any suggestions???
Would unpluging or change the lockup solenoid help?
And I hope someone can help me.
I have a 1980 , stock 350. Idles great revs even nicer, but when I put it in gear (turbo 350) it just dies, in both fwd and reverse.
A friend of mine told me it may be that my converter is locked????
Any suggestions???
Would unpluging or change the lockup solenoid help?
