TH-350C question - Pirate4x4.Com : 4x4 and Off-Road Forum

sapperfitz · 12-29-2005, 06:35 AM

I have a TH-350C tranny in my '82 K10. I don't know what it is out of originally. It has a two pronged electrical connector coming out of the passenger side of the case just behind where the TV cable goes in. Does anyone know what this is? Thanks.

echos · 12-29-2005, 07:15 AM

You positive it isnt a 700r4?

KWTMECH · 12-29-2005, 07:26 AM

700s had the connector on the drivers side. Is the connector internal to the case or is it like an oil pressure switch?

sapperfitz · 12-29-2005, 07:58 AM

The connector is like an oil pressure switch. The TH350C has a locking converter like the 700r4, and has the same connector on the drivers side. On some older, non-locking TH350's there was a solenoid for the TCS in the same spot, but I thought the TCS was discontinued in '75 and the TH350C didn't come out until around 1980.

KILLER"B"3 · 12-29-2005, 08:02 AM

It is a lockup 350, the inards are the same. The pump and valvebody are different as well as the case. It can be made to be a non lockup trans but you will have to use some regular t-350 parts. There is nothing wrong woth that trans, I do alot of these for the fact that normal t-350 are getting harder to find. To use the lockup all you need is a brake/lockup switch from an 85 and newer s-10. One wire is the 12v sorce from the switch, and the other is a ground.

sapperfitz · 12-29-2005, 09:10 AM

Sorry, let me try to clarify my question. I am using the lock-up. I know all about the transmission except what the connector on the passenger side was for. The reason I need to know is because I have a leak originating there and it is in a very cramped space. I need to know what it is so I can go to autozone, see if they have one, ask if I can look at it, and then figure out what size socket fits it. It will require a deep socket bigger than 1". I don't have any bigger than 1" and only want to buy 1 socket.

chevychevrolet · 12-29-2005, 10:22 AM

some of those trannys had a reverse light switch in that location.

sapperfitz · 12-29-2005, 04:20 PM

I figured out what it was. It is a pressure sending unit. I don't know what it was for, though. Anyone familiar with GM Transmission Controlled Spark? I suspect that is what it was for. Thanks for all the help.

KWTMECH · 12-29-2005, 06:23 PM

You're right, TCS. That is why I asked if it looked like an op switch. Just plug it off. TCS was GMs way of controlling Nox in the earlier vehicles, it would not allow vac advance until the trans shifted into 3rd.

12-29-2005, 06:35 AM	#1 (permalink)
sapperfitz Registered User Join Date: Dec 2005 Member # 64299 Location: Colorado Springs Posts: 18	TH-350C question I have a TH-350C tranny in my '82 K10. I don't know what it is out of originally. It has a two pronged electrical connector coming out of the passenger side of the case just behind where the TV cable goes in. Does anyone know what this is? Thanks.

12-29-2005, 08:02 AM	#5 (permalink)
KILLER"B"3 Registered User Join Date: Oct 2005 Member # 54970 Location: Nashville Tn. Posts: 415	It is a lockup 350, the inards are the same. The pump and valvebody are different as well as the case. It can be made to be a non lockup trans but you will have to use some regular t-350 parts. There is nothing wrong woth that trans, I do alot of these for the fact that normal t-350 are getting harder to find. To use the lockup all you need is a brake/lockup switch from an 85 and newer s-10. One wire is the 12v sorce from the switch, and the other is a ground. __________________ stuck in the garage

12-29-2005, 09:10 AM	#6 (permalink)
sapperfitz Registered User Join Date: Dec 2005 Member # 64299 Location: Colorado Springs Posts: 18	Sorry, let me try to clarify my question. I am using the lock-up. I know all about the transmission except what the connector on the passenger side was for. The reason I need to know is because I have a leak originating there and it is in a very cramped space. I need to know what it is so I can go to autozone, see if they have one, ask if I can look at it, and then figure out what size socket fits it. It will require a deep socket bigger than 1". I don't have any bigger than 1" and only want to buy 1 socket. Last edited by sapperfitz; 12-29-2005 at 09:13 AM.

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12-29-2005, 07:15 AM	#2 (permalink)
echos Registered User Join Date: Nov 2005 Member # 61997 Posts: 64	You positive it isnt a 700r4?

12-29-2005, 07:26 AM	#3 (permalink)
KWTMECH Registered User Join Date: Sep 2002 Member # 13786 Location: moved 7 miles to colfax, ca. Posts: 4,224	700s had the connector on the drivers side. Is the connector internal to the case or is it like an oil pressure switch?

12-29-2005, 07:58 AM	#4 (permalink)
sapperfitz Registered User Join Date: Dec 2005 Member # 64299 Location: Colorado Springs Posts: 18	The connector is like an oil pressure switch. The TH350C has a locking converter like the 700r4, and has the same connector on the drivers side. On some older, non-locking TH350's there was a solenoid for the TCS in the same spot, but I thought the TCS was discontinued in '75 and the TH350C didn't come out until around 1980.

12-29-2005, 10:22 AM	#7 (permalink)
chevychevrolet Registered User Join Date: Jul 2005 Member # 50553 Location: Billings, Mt Posts: 106	some of those trannys had a reverse light switch in that location.

12-29-2005, 04:20 PM	#8 (permalink)
sapperfitz Registered User Join Date: Dec 2005 Member # 64299 Location: Colorado Springs Posts: 18	I figured out what it was. It is a pressure sending unit. I don't know what it was for, though. Anyone familiar with GM Transmission Controlled Spark? I suspect that is what it was for. Thanks for all the help.

12-29-2005, 06:23 PM	#9 (permalink)
KWTMECH Registered User Join Date: Sep 2002 Member # 13786 Location: moved 7 miles to colfax, ca. Posts: 4,224	You're right, TCS. That is why I asked if it looked like an op switch. Just plug it off. TCS was GMs way of controlling Nox in the earlier vehicles, it would not allow vac advance until the trans shifted into 3rd.