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torque converter symptoms


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isrummell's Avatar
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April 18th, 2010, 7:41 AM   #1  
torque converter symptoms

what are the symptoms of the torque converter going bad

 
maxxman04's Avatar
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April 18th, 2010, 9:30 AM   #2  
could have noticeable slippage in all gears, higher than normal rpm's to shift. what is your particular rig doing?

 
isrummell's Avatar
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April 18th, 2010, 11:05 AM   #3  
it drives normal pretty much the only thing i notice is when i cruising it runs about 200 rpms faster and it feels like it slips out of gear real quick then back in but the rp,s dont jump when it does it

 
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April 18th, 2010, 11:09 AM   #4  
you checked fluid level/condition? filter changed?

 
isrummell's Avatar
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April 18th, 2010, 11:37 AM   #5  
fluid level is fine never checked the filter

 
isrummell's Avatar
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April 18th, 2010, 2:57 PM   #6  
how often are u supposed to change the fluid. my dad always said he put over 200,000 miles on a few cars and changed the tranny fluid. lol but they probably leaked enough that he didnt have to

 
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April 18th, 2010, 3:02 PM   #7  
Depends on teh vehicle, if it's never been changed, it's okay to change the fluid and filter, but don't flush it. I'm flushign mine every 36k. Along with everythign else except the radiator.

 
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April 18th, 2010, 3:03 PM   #8  
35k-40k miles fluid and filter.

 
wellmax's Avatar
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April 18th, 2010, 10:29 PM   #9  
my experience with lose of torque converter


2000 model Chevy 2500 series, 350 engine, OBS, transmission flushed at 60K; torque converter gave way at 82K. Truck used to pull a 6500# travel trailer less than 2% of time most time it just hauls me around and is driven very easy.

When I first started off in the morning with the transmission oil cold; transmission torque converter would lockup fine for about 5-6 miles or even further if I stayed on level roads.

However, if I came to a hill the torque converter would unlock and then all shifts after that would be hard/jerky shifts until I stopped, turn motor off for about 30 secs.

Transmission tech said turning motor off reset the computer; torque converter would lockup again until I got to the next hill. Sometimes, it would unlock on level road, tech said if not repaired it would get to the point the transmission would not pull and I would have to have it repaired.

Tech said the reason for the hard shifts was the computer knew some type of transmission slippage was happening, so it automatically increases the shift pressure to insure the clutch discs do not slip and burn. (Do not know if this is true or not, but went torque converter would not lockup, all shifts were very hard/jerky shifts like it had a shift kit installed).

He said some type piston or seal in torque converter was busted/cracked and would not allow the torque converter to maintain the proper oil pressure to stay engaged.

All I know, is a new torque converter fixed the problem, just a mechanical failure. Transmission was fine, just replaced torque converter.

Tech said GM changed something in the 2000 model torque converter (4L80E transmission) that caused a number of defects, corrected the problem in the 2001 model.

When I arrived at the shop to pick my truck up there was another 2000 model NBS chevy 2500 series waiting to be worked on, he said it had the same problem. Both NBS and OBS 2000 models got the same 4L80E transmission.

Good luck with yours,

Note: Had GM tech run scan on compute because my engine service light never came on. His scanner showed what he called hidden codes, he said the fact that each time I turned motor off it reset the computer may have mast the problem and not have allowed the engine service light to come on and stay on.

Engine service light was working properly.

I bet its not overdrive you're losing but its the torque converter unlocking because of slippage. The cheap fix involves having someone install a kit in the valve body, the torque convertor clutch piston in the valve body wears the valve body and the pressure leaks by the piston causing the torque convertor to slip when it should not. And as another poster mentioned, when the PCM detects the slippage it commands max line pressure that gives you the hard shifting




.

 
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April 19th, 2010, 3:53 AM   #10  
sounds like it was not the actual verter but the TCC circuit. it controls your lockup. inside your verter is a clutch, and when mister compooper says lockup, in teh valve body a valve is triggered and then pressure flows to the verter to engage the clutch. and then your verter locks the motor and trans together. causing better fuel economy and a happy driving situation. when that clutch is badly worn it wont want to engage, or, what you called the KIT, is actually the new valve. sometimes you have to reem it, other times if its bad enough, you sleeve it. But, hidden codes, well... thats why i want a TECH 2 Scanner. lady came into my work, said her car overheated, wont go over 20 mph bla bla we broke it bla bla bla, i said you got a blown cat and your exhaust is clogged, we ran TECH 2 and the compooper told us her cat was blown for 13k miles. lol. yea we didnt do it.
if you have someone that is able to fully scan the computer. tell them to look in the paramaters of the TCC circuit. see how long it takes for the verter to lock up. the going theory is when it reads at or below the 50's calculation, its okay. when it goes 65-up its said to be time for a replacement verter clutch or verter.
gotta love automatic transmission 1135 at school!

 
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