Torque Converter???? [Archive] - Forum


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02-11-2004, 05:50 PM
Alright all, if you recall my car "shuddering" problem, turns out as many suspected that it is infact my torque converter. What would replacing that be like? Im assuming that by the time I payed labor to have a new one swapped in I might as well have gotten a new transmission right? ANy idea how much this will run me?

Its a '99 with the 4t40E. THANKS

02-11-2004, 10:01 PM
What are you experiencing?

02-12-2004, 05:36 AM
One of my thousand other threads on this (

02-12-2004, 06:02 AM
Dave, the transmission has to be dropped, and the torque converter comes out. Your looking at about $100 for a new torque conveter (unless you want a high stall), and about 3 hours of labor. Total should be no more then $500 installed. If your getting a whole new transmission, your looking at no more then $1800 installed.

Edit: Not sure if you know this or not, but the only reason its shuttering in 4th gear is b ecause of TCC lockup.

02-12-2004, 06:29 PM
Is TCC lockup ( i have no idea what that is) something that can be fixed without replacing all that junk? Thanks BTW!

02-12-2004, 06:58 PM
The TCC lockup or Torque Convertor Clutch Solenoid can be replaced without removing the tranny. I've never done it but I have a friend who is a mechanic at the local pontiac dealer. We were just talking about those TCC solenoids going bad over a case of beer this weekend. The way he talked it isn't that hard to fix, but you better leave it to someone who knows what they are doing.

FYI everyone...he said that it is a very common problem along with those intake gaskets. So keep an eye out in the snow under your ride for anitfreeze drops. He said those gaskets go around 50 to 60 K.

02-12-2004, 10:01 PM
Thanks for the info silver. That manifold gasket thing is pretty notorious around here. Most of the 3.4 guys have a problem with it sooner or later. One advantage to my 2.4. Of course instead of that gasket, I have the bad water pump syndrome, a measly 700 dollar job...:rolleyes:

02-12-2004, 11:19 PM
Not to pick...but isn't our trans the 4t45e, not the 4t40? Just curious, and making sure I have my info straight!


02-13-2004, 06:33 AM
GT's have the 4T45E, SE's with the 4 cylinder have the 4T40E. The differance is strength (not by much) and mostly gearing.

02-13-2004, 10:02 AM
How did you come to the determination that its the Torque Converter? Diagnostics? Because if its just the selnoid, it shouldn't be too bad a fix. I actually just fixed my sisters Torque Converter selonoid on my old buick Century... it was sticking on and would stall the car at a stop. I just unhooked it, no more torque converter lockup, but its just a run around town car, so its an easy solution. It'll hurt highway mileage a little, but it'll keep her moving.

02-13-2004, 10:34 AM
Does more then that...if you unplugged the bulk head connector, your messing with a lot of things. First, it cant get the transmission temp. 2nd, since you have no lockup, your trans will overheat much easier and decrease the life of the transmission.

02-13-2004, 10:45 AM
No, not the bulk head connector, just the TCL selonoid. It would be a bad idea on a modern electronicly controlled tranny, this ones in an '89 Century, kickdown cable and all, so no computer problems. I've determined I can't kill that tranny either. Its got 190,000k on it, and I've towed more with that car than most people ever will with their pickup trucks. Boats, trucks, cars, trailers, you name it, I've had it behind me at one point with that car. Tranny still works great. Big cooler helps.

02-13-2004, 10:50 AM
Ahh, ok. I thought it was newer and you disconnected the bulk head.

02-13-2004, 01:44 PM
Ok, I know im an idiot, but what does a torque converter even do?

02-13-2004, 02:12 PM
The torque converter acts like the clutch on a stick shift. When at a idle, it allows the motor to spin freely untill it hits the stall speed. The stock stall is usually between 700-1100. When it hits that RPM's, that when the power gets transferred to tires. Thats why high stall torque converters are good on cars with lots of power. All they do is slam the gas, and it doesnt go untill you hit say 3000 or 3500 RPM's for a hard launch.

When the TCC (Torque Converter Clutch) locks up, that means that its not spinning by fluid, but rather the speed is matched with the actual RPM's. This way there is no slippage. Thats why if you have a misfire, you can tell its misfiring when its locked up because its like direct drive then.

Edit: You can learn all about them here: