th350 or th350C - The 1947 - Present Chevrolet & GMC Truck Message Board Network

my new 72 · 07-01-2002, 09:52 PM

What is the diffeence? Is it just that the C was the newer one made after 1980, and the th350 before 1980. Or does the C mean it requires a locking converter. What would it take to wire a locking torque converter in my 72.

Longhorn Man · 07-01-2002, 10:35 PM

Th350C is a locking verter...t is supposed to be run off of some kind of vacume switch.

Super Chevy · 07-01-2002, 11:34 PM

I have a TH350C,acts exactly like a th350,you dont have to hook the lock-up thing up,but i am,it has two prongs,im gonna hook it up to a cruise control brake swith so that it gets power when im off the brake and itll onlock the converter when im on the brake,itll lock up automatically when it has power to it around 50 but it wont un-lock itself i dont thing ,thats why im going with a switch...

LIKE This - http://www.700r4.com/Tech/TCC/GM_Switch.htm

Longhorn Man · 07-01-2002, 11:45 PM

From my understanding (I've been told this, but have no looked into it) The tranny will slip a little more than it should when yu do not put it in lock up.

Super Chevy · 07-01-2002, 11:51 PM

true longhornmail,my truck pulls like a bish off the line when my verter isnt hooked up,not sure if that causes it,but it jumps up to 1200 befor it takes off and takes off really hard,like your pulling a wholeshot all the time...

Longhorn Man · 07-01-2002, 11:57 PM

If it jumps to 1200 when you launch it, it is either a high stal (term used loosely) low on fluid, or gettin ready to puke.
My 1900 stall verter lunches at about 17-ish.
Actually, that is only a couple hundred above stock.

Super Chevy · 07-02-2002, 12:37 AM

its fresh and has low miles on it,i have gone though it befor i put it in, fluid is right on,but it did come out of a heavy utility box truck/van,mabe they had higher stalls? ( crossing fingers )

S-C

my new 72 · 07-02-2002, 08:16 AM

Is there a way to turn it on to lock up during takeoff, and then unlock untill cruiseing speed. I have seen that switch. I am gonna get one of those too.

crew70 · 07-02-2002, 09:00 AM

the converter will not lock up if it is not pluged in.
if you are toeing something with a 700r4 and you are over heating and dont have the power to cruz down the hyway all you have to do is unplug your converter . what happens is when the converter locks up it dosnt pump the oil as fast true the trani and cooler so the oiul gets hot and the motor is beeing luged so it getts hot and boils the oil out of the trani dipstick. fried!!!
what i do is install a toggle switch to turn of the converter when towing. saves the trani.gm knows this because they later put towing bottons in there trucks to do this very thing( also changing the shifting).

Longhorn Man · 07-02-2002, 05:45 PM

On the TH350C, with the vacume switch, it would come out of lock up when you speed up.

07-01-2002, 09:52 PM	#1
my new 72 faster, faster, faster Join Date: Dec 2001 Location: Houston ,Texas ,USA Posts: 1,354	th350 or th350C What is the diffeence? Is it just that the C was the newer one made after 1980, and the th350 before 1980. Or does the C mean it requires a locking converter. What would it take to wire a locking torque converter in my 72. __________________ I'm going to Law School, wanna debate? It's good practice.

07-02-2002, 08:16 AM	#8
my new 72 faster, faster, faster Join Date: Dec 2001 Location: Houston ,Texas ,USA Posts: 1,354	Is there a way to turn it on to lock up during takeoff, and then unlock untill cruiseing speed. I have seen that switch. I am gonna get one of those too. __________________ I'm going to Law School, wanna debate? It's good practice.

07-02-2002, 09:00 AM	#9
crew70 Registered User Join Date: Jan 2002 Location: shafer,mn,usa Posts: 316	the converter will not lock up if it is not pluged in. if you are toeing something with a 700r4 and you are over heating and dont have the power to cruz down the hyway all you have to do is unplug your converter . what happens is when the converter locks up it dosnt pump the oil as fast true the trani and cooler so the oiul gets hot and the motor is beeing luged so it getts hot and boils the oil out of the trani dipstick. fried!!! what i do is install a toggle switch to turn of the converter when towing. saves the trani.gm knows this because they later put towing bottons in there trucks to do this very thing( also changing the shifting). __________________ 70 chevy 3/4 ton 4x4 402ci crewcab 3/4ton 94 gmc 1 ton dually crewcab 454ci 99 suburban 5.7 2001 500cc ski-doo mxz 95 500cc ski doo fan 650 bombardiar 4 wheeler

07-01-2002, 10:35 PM	#2
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Th350C is a locking verter...t is supposed to be run off of some kind of vacume switch.

07-01-2002, 11:34 PM	#3
Super Chevy Registered User Join Date: Feb 2001 Location: Ohio Posts: 1,025	I have a TH350C,acts exactly like a th350,you dont have to hook the lock-up thing up,but i am,it has two prongs,im gonna hook it up to a cruise control brake swith so that it gets power when im off the brake and itll onlock the converter when im on the brake,itll lock up automatically when it has power to it around 50 but it wont un-lock itself i dont thing ,thats why im going with a switch... LIKE This - http://www.700r4.com/Tech/TCC/GM_Switch.htm

07-01-2002, 11:45 PM	#4
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	From my understanding (I've been told this, but have no looked into it) The tranny will slip a little more than it should when yu do not put it in lock up.

07-01-2002, 11:51 PM	#5
Super Chevy Registered User Join Date: Feb 2001 Location: Ohio Posts: 1,025	true longhornmail,my truck pulls like a bish off the line when my verter isnt hooked up,not sure if that causes it,but it jumps up to 1200 befor it takes off and takes off really hard,like your pulling a wholeshot all the time...

07-01-2002, 11:57 PM	#6
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	If it jumps to 1200 when you launch it, it is either a high stal (term used loosely) low on fluid, or gettin ready to puke. My 1900 stall verter lunches at about 17-ish. Actually, that is only a couple hundred above stock.

07-02-2002, 12:37 AM	#7
Super Chevy Registered User Join Date: Feb 2001 Location: Ohio Posts: 1,025	its fresh and has low miles on it,i have gone though it befor i put it in, fluid is right on,but it did come out of a heavy utility box truck/van,mabe they had higher stalls? ( crossing fingers ) S-C

07-02-2002, 05:45 PM	#10
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	On the TH350C, with the vacume switch, it would come out of lock up when you speed up.



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