How hard to change out torque converter 4L80E-1 ton Chevy Truck C3500

[Big Bubba]

All right,
I have a question for all the transmission guys out there. How hard is it to swap out a torque converter on a 2000 year, C3500, 1-Ton Chevy crew cab truck? I lose fourth gear after it has been driven a while and when the transmission engine is fully warmed up and I get no check engine light on the dash. I have read that the torque converter could be an issue causing loss of fourth gear due to a worn out lock-up clutch or the backing plate that the clutch engages into is cracked and causing loss of pressure and slipping. Here is the pi that someone on another forum has posted. And when this happens my rpms go up it drops down to third gear and I get firmer/harder shifts going from 1 to 2 gears. Here is the pi..

PIP3047A: 00-01 4L80-E Harsh TCC Apply/DTC P1870 or P0741 - kw 4L80E apply automatic converter DTC hard harsh shift TCC torque transmission - (Sep 16, 2004)

Subject:00-01 4L80-E Harsh TCC Apply/DTC P1870 or P0741

Models:.


The following diagnosis might be helpful if the vehicle exhibits the symptom described in the PI.
<A href="http://gsi.xw.gm.com/si/showDoc.do?docSyskey=1550127&from=sm#ss1-1550127">Condition/Concern:

2000 - 2001 light duty trucks, vans and utilities equipped with the 4L80E automatic transmission may experience a harsh TCC apply and/or a DTC P1870 or possible P0741.
<A href="http://gsi.xw.gm.com/si/showDoc.do?docSyskey=1550127&from=sm#ss2-1550127">Recommendation/Instructions:

Now that you have completed the service diagnostics in SI with no resolution, replace the torque converter to repair the concern.
.
Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance.

If the torque converter need to be replaced then how hard of a job is it for an average back yard mechanic. I can turn a wrench and have some mechanical ability to do the job. Let me know and I did replace the valve body with a brand new one about a month ago and it is still dropping out of fourth gear/overdrive after it has been driven a while and warmed up. Also, when I dropped the transmission pan the fluid that I drained into a yellow catch pan looked pretty dark dark red to almost black but didnt seem to smell burned to me. What do you think???

 

[rockyrude]

Re: How hard to change out torque converter 4L80E-1 ton Chevy Truck C3500

Does overdrive drop completely out or does it try to re-engage only to drop back out? On mine when the torque converter clutch went out, it would drop out of overdrive then try to re-engage and drop out again. Either way, the trans get to come out.

 

[Bondo]

Re: How hard to change out torque converter 4L80E-1 ton Chevy Truck C3500

All right,
I have a question for all the transmission guys out there. How hard is it to swap out a torque converter on a 2000 year, C3500, 1-Ton Chevy crew cab truck? I lose fourth gear after it has been driven a while and when the transmission engine is fully warmed up and I get no check engine light on the dash. I have read that the torque converter could be an issue causing loss of fourth gear due to a worn out lock-up clutch or the backing plate that the clutch engages into is cracked and causing loss of pressure and slipping. Here is the pi that someone on another forum has posted. And when this happens my rpms go up it drops down to third gear and I get firmer/harder shifts going from 1 to 2 gears. Here is the pi..

PIP3047A: 00-01 4L80-E Harsh TCC Apply/DTC P1870 or P0741 - kw 4L80E apply automatic converter DTC hard harsh shift TCC torque transmission - (Sep 16, 2004)

Subject:00-01 4L80-E Harsh TCC Apply/DTC P1870 or P0741

Models:.


The following diagnosis might be helpful if the vehicle exhibits the symptom described in the PI.
<A href="http://gsi.xw.gm.com/si/showDoc.do?docSyskey=1550127&from=sm#ss1-1550127">Condition/Concern:

2000 - 2001 light duty trucks, vans and utilities equipped with the 4L80E automatic transmission may experience a harsh TCC apply and/or a DTC P1870 or possible P0741.
<A href="http://gsi.xw.gm.com/si/showDoc.do?docSyskey=1550127&from=sm#ss2-1550127">Recommendation/Instructions:

Now that you have completed the service diagnostics in SI with no resolution, replace the torque converter to repair the concern.
.
Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance.

If the torque converter need to be replaced then how hard of a job is it for an average back yard mechanic. I can turn a wrench and have some mechanical ability to do the job. Let me know and I did replace the valve body with a brand new one about a month ago and it is still dropping out of fourth gear/overdrive after it has been driven a while and warmed up. Also, when I dropped the transmission pan the fluid that I drained into a yellow catch pan looked pretty dark dark red to almost black but didnt seem to smell burned to me. What do you think???

Ayuh,... Ya either gotta pull the motor, or drop the transmission, as the T/C lives 'tween the two...

 

[gm280]

Re: How hard to change out torque converter 4L80E-1 ton Chevy Truck C3500

Now knowing if your 1 ton truck is four wheel drive or not, there could be some cross members and/or transfer case to remove just to get to the transmission to remove it. It isn't actually hard but does take some time and understanding how the things have to be removed and in what order to remove the transmission... And if it is four wheel drive, a lot of those parts will be on the heavier side. So make sure you are not under any of those parts then when you take out the last fasteners and if you can buy or rent a transmission jack, it makes such work a little more bearable... Take lots of pictures before you start any work if you have never done any of this before. It never hurts to see how everything was fitted before removing it all and wondering how this line or that bracket was originally installed. Oh and one last thing. Find you a sucker, I mean friend to help you...

 

[CharlieB]

Re: How hard to change out torque converter 4L80E-1 ton Chevy Truck C3500

Before replacing that converter I would want someone to diagnose the problem, TO BE SURE.

With everything warmed up find a nice long stretch of clear road, from a dead stop speed up to 55 - 60 while carefully counting shifts.

Pay attention, you should fell the 1 -2 shift, the 2 -3 shift, the 3 - OD shift, then feel the lockup of the converter.

Some trans programs will lockup in 3d, then shift unlocked into OD then lockup again, so you can feel/sense what seems to 5 gears.

my point is, if it is a shifting problem, most likely the trans needs to be opened, either the valve body or a clutch has a problem.

This is why it may be to your benefit to have a real trans guy check it out and give you a firm estimate, even if it cost you $30 to do it cause if you change the converter and it does not cure the problem, you are not going to be a happy camper.

I've made these kinds of mistakes. Ticks me off, so I tend to be a bit more conservative now.

 

[Big Bubba]

Re: How hard to change out torque converter 4L80E-1 ton Chevy Truck C3500

CharlieB,
Yeap, I am taking it to a local transmission shop in town next week for them to do a thorough check on why I am losing fourth gear or overdrive and it drops down to third gear and never shifts back to fourth gear after that until I shut the engine off for about 20 seconds or so. It is either the fourth clutch or the torque converter but not sure which one. I did notice that when I dropped the pan to swap out the valve body that the fluid was almost black when it was drained into a yellow drain catch pan. So something in the tranny must be worn out for it to look that color. I will see what they say next week and go from there.

 

[Bamaman1]

Re: How hard to change out torque converter 4L80E-1 ton Chevy Truck C3500

Trannys are not something you just throw parts into. They must be diagnosed 100% of the time.

And have you thought about going to the big Chevy truck blog to ask about the problem. When you have millions of such trucks on the road, their blogs are looked at by millions of knowledgible truck owners with transmission/torque converter experience.

I do know that transmissions are the weakest link in any truck's powertrain. Auto trannys don't last nearly as long as is thought in 1 ton and 3/4 ton vehicles. And the reason for most transmissions failing is heat--running too fast with too much weight. Go over 220 degrees for very long, and they're simply cooked. And to think that the failures can often be prevented by adding a $110 secondary transmission cooler like a TruCool or B&M. And every major auto parts store sells tranny coolers.

 

[CharlieB]

Re: How hard to change out torque converter 4L80E-1 ton Chevy Truck C3500

Parts for a complete rebuild are surprisingly cheap compared to the cost of taking the vehicle in and having it done.

Couple hundred for the kit and another couple for a new converter, compared to $2500 to $3500 for the trans shop to do it.

Carry the trans in and set it on their bench can save you substantially and still get you some warranty on the trans.

 

[Boomyal]

Re: How hard to change out torque converter 4L80E-1 ton Chevy Truck C3500

Just to give you an idea, it cost me about $600. to pull the trans on my E150 and replace a cracked flex plate. The plate was about $100. so figure the labor at about $500. They could have replaced the TC for the same effort.

And yes, there were crossmember(s) and exhaust to deal with.

 

[Bamaman1]

Re: How hard to change out torque converter 4L80E-1 ton Chevy Truck C3500

Last time I had a tranny rebuilt, it was a 13 hour base rate manual job.

My son in law is a superlative Chevy mechanic. On a 2 wheel drive C1500, he can drop the tranny and rebuild it in 75 minutes. Talk about beating the book! One of his mechanics can even beat that time.

And you can see how to rebuild them on UTube.com. There are also many sources on how to rebuild GM trannys online and in print. With millions of vehicles comes incredible UTube.com info.

 

[MTboatguy]

Re: How hard to change out torque converter 4L80E-1 ton Chevy Truck C3500

Last time I had a tranny rebuilt, it was a 13 hour base rate manual job.

My son in law is a superlative Chevy mechanic. On a 2 wheel drive C1500, he can drop the tranny and rebuild it in 75 minutes. Talk about beating the book! One of his mechanics can even beat that time.

Which NASCAR team did you say they work for?

:facepalm:

 

[CharlieB]

Re: How hard to change out torque converter 4L80E-1 ton Chevy Truck C3500

................................

My son in law is a superlative Chevy mechanic. On a 2 wheel drive C1500, he can drop the tranny and rebuild it in 75 minutes. Talk about beating the book! One of his mechanics can even beat that time.

..............................................

I got a BIL in the NW that would hire him in a heartbeat, your son could end up being one of the best paid trans mech anywhere!

PM me if he wants the name, location, and phone # of Brad's business

 

[hrdwrkingacguy]

Re: How hard to change out torque converter 4L80E-1 ton Chevy Truck C3500

My son in law is a superlative Chevy mechanic. On a 2 wheel drive C1500, he can drop the tranny and rebuild it in 75 minutes. Talk about beating the book! One of his mechanics can even beat that time.

As someone who worked at a Cottman transmissions when I was younger, I can say 100% that you can't rebuild that transmission from pulling it to building it in 75 minutes(properly and reliably)...I used to be called 2 to 1 Jeff at Cottman because I could pull out 2 700R4's to anyone's one...23 minutes was the fastest I ever did one...Complete tear down, hard parts in the parts washer and put back together properly with new clutches and bands and torque converter was a hour and a 1/2 if you were rocking and rolling...

I'm sure there are corners to cut and time to be save...The moral is I wouldn't want that kind of attention paid to my transmission if I were having it rebuilt...I have seen so many self destruct after 300 miles due to things being missed...

PS I have seen competitions where things are turned around uber fast like the wyotech guys changing a LS motor in 43 minutes and driving it off...Think of it like sex, Its always better to take your time and do it right...