2000 Year, Chevrolet, C3500 4L80E Transmission?

[Big Bubba]

Hello everyone,
How is everyone doing today? Well I got a question concerning my 2000 year, C3500, Chevrolet Dually. Anyway, I need to know if automatic transmission fluid slowly oozing out of the electrical pass through connector on the drivers side of the truck will cause the transmission to lose overdrive occasionally and have harsher shifting? I removed mine, the electrical connector, today for the first time and of course a little bit of automatic transmission fluid was oozing out especially out of the small, tiny contact holes inside that connector. Let me know if that would cause an issue. Other than that the transmission shifts flawlessly when it does not happen to kick out of overdrive. I did go to AAMCO transmissions in town today and they told me I need a complete rebuild and they found a code P1870, "Transmission Component Slipping". No other codes where found. I don't have much money to through away and if the pass through connector with a little automatic transmission fluid is causing my issues then I will purchase a brand new interior pass through electrical connector and replace that and the tranny fluid and filter as well. That will be alot cheaper than paying for a full rebuild and also my motor has approximately 126,000 miles on it. Thank you for your help, Bob

 

[rockyrude]

Re: 2000 Year, Chevrolet, C3500 4L80E Transmission?

I wish I could remember if ATF is electrically conductive. The ATF could be shorting the signal causing PCM issues.

 

[RogersJetboat454]

Re: 2000 Year, Chevrolet, C3500 4L80E Transmission?

ATF is not electrically conductive. Half the electrical components inside an automatic trans have no insulation, and are bathed in ATF.

If the leaking pass-through is causing enough fluid loss that the trans dosen't have enough fluid to work correctly, that's a problem. If it's just weeping fluid, but the fluid level is still around a normal level, that's not a problem.

When is the last time you did a transmission flush to it? A truck pulling heavy loads, or plowing, we usually recommended them to be done at least every 30K.

 

[Big Bubba]

Re: 2000 Year, Chevrolet, C3500 4L80E Transmission?

RogerJetBoat 454,
So you don't think that my pass threw connector wet with automatic transmission fluid is not causing and issue with overdrive kicking out and going into limp mode once in a while. Like I said when the transmission is working it shifts great but it does kick out of overdrive sometimes going into limp mode and harsher shifting. I was planning on replacing the internal transmission pass threw connector and just cleaning off the exterior pass threw connector with CRC Contact cleaner and using air compressor to blow out the connector and I was also going to replace the transmission filter and fluid. What do you think? Thanks again, Bob

 

[NYBo]

Re: 2000 Year, Chevrolet, C3500 4L80E Transmission?

I'm not surprised at what that transmission shop told you.
AAMCO= All Automatics Must Come Out

 

[Big Bubba]

Re: 2000 Year, Chevrolet, C3500 4L80E Transmission?

NyBo,
That is too funny. I am glad I have did some major on-line researching and DID NOT fall for the full, complete rebuild on my transmission. There are other things it could be. Just today, I drove my truck and the transmission shifted flawalessly without any hiccups. Then on my return home it kicked out of overdrive and at a stop light I put my truck in park shut it off and restarted it and she drove fine. I am thinking some kind of electrical issue like that wet pass through connector going into my transmission might be the culprit and causing my head aches on my transmission. I did find that someone had the same thing happen on there truck and they changed out there internal pass through electrical connector wire harness because of fluid leakage, TCC Solenoid, Pressure Control solenoid, and there transmission issue is solved. I think, I hope, that that will fix my current issue, I just have to wait until 1 January 2013 to purchase these parts so I can do the job. Wish me luck because I need it and hoping, praying that I DON"T need a rebuild on my transmission.

 

[RogersJetboat454]

Re: 2000 Year, Chevrolet, C3500 4L80E Transmission?

RogerJetBoat 454,
So you don't think that my pass threw connector wet with automatic transmission fluid is not causing and issue with overdrive kicking out and going into limp mode once in a while. Like I said when the transmission is working it shifts great but it does kick out of overdrive sometimes going into limp mode and harsher shifting. I was planning on replacing the internal transmission pass threw connector and just cleaning off the exterior pass threw connector with CRC Contact cleaner and using air compressor to blow out the connector and I was also going to replace the transmission filter and fluid. What do you think? Thanks again, Bob

In a nutshell... No. ATF does not interfere with the electrical function of the tranny. Most oils act as an insulator, not a conductor. If leaking oil into a connector was a problem, all the manufacturers would be bumming, most the solenoid/sensor connections inside the transmission are exposed to oil.

Hate to say this, but it's sounding like the PCM is detecting slipping, and ramping up line pressure when it does. When you cycle the key, your truck is probably reverting back to normal shifting.

Changing out the filter, and a few quarts of ATF is usually a last ditch effort. And as I said in my previous post, sometimes it makes matters worse when there's new fluid added to a sick transmission.

Someone on the internet shot-gunning part's into their tranny got lucky. What most likely fixed their issue was either the TCC, or PCC. Those can either get plugged up with crap (clutch material/metals), or can have a bad solenoid (usually resulting in a circuit code).

You never said if you've ever done a flush...

 

[Big Bubba]

Re: 2000 Year, Chevrolet, C3500 4L80E Transmission?

I have done some research and they say that the valve body being aluminum and having steel valves/spools wears the bore out in the TCC isolator boar etc and that could cause issues with the high pressure and hard shifting and loose of overdrive when the transmission comes up to temp and the fluid thins out casuing the pressure to bleed off and causing the PCM to increase line pressure to max and cause it to go into limp mode and code P1870 thrown. Also could be a bad torque convertor. I am just confuse on what to do??? I guess I need to get it on a live scanner and see what it is that is causing the issue. I just hope I do not have to do a rebuild becuase I do not have $2,000.00 to pay for it but if it is a worn valve body or a bad torque convertor or torque convertor going out I could swing that repair. Decisions, Decisions to be made???? I just need someone with some knowledge to help me out here. Take care and thanks for the replys so far.

RogersJetBoat454:

No I have never done a flush on this transmission since I have owned this truck for 3 months so far. So you think I should do that?

 

[Big Bubba]

Re: 2000 Year, Chevrolet, C3500 4L80E Transmission?

RogersJetBoat454:

No I have never done a flush on this transmission since I have owned this truck for 3 months so far. So you think I should do that? I also do not know the history on this transmission either.

 

[RogersJetboat454]

Re: 2000 Year, Chevrolet, C3500 4L80E Transmission?

I have done some research and they say that the valve body being aluminum and having steel valves/spools wears the bore out in the TCC isolator boar etc and that could cause issues with the high pressure and hard shifting and loose of overdrive when the transmission comes up to temp and the fluid thins out casuing the pressure to bleed off and causing the PCM to increase line pressure to max and cause it to go into limp mode and code P1870 thrown. Also could be a bad torque convertor. I am just confuse on what to do??? I guess I need to get it on a live scanner and see what it is that is causing the issue. I just hope I do not have to do a rebuild becuase I do not have $2,000.00 to pay for it but if it is a worn valve body or a bad torque convertor or torque convertor going out I could swing that repair. Decisions, Decisions to be made???? I just need someone with some knowledge to help me out here. Take care and thanks for the replys so far.

Valve bodies do wear, and often times manufactures have updated certain things in the valve bodies to fix problems. Looking up this issue on Mitchell on Demand, GM released a service bulletin (01-07-30-023B) regarding issues with worn valve bodies that apply to '96-'99 model year trucks. BUT... this bulletin was for trucks with the 4L60-E. I just hope where ever you're looking for info, people aren't mixing problems from one common truck transmission to another.

If you want to get a good idea how badly the clutches are worn, pull the pan and look at what's waiting for you in the bottom.

If there's a little bit of dust at the bottom (grey mud from the clutches), and a tiny bit of metal stuck to the magnet, then things are relatively normal. You could roll the dice and see if changing out the control aspect (sensors, possible valve body) will fix your issue. If there is thick layer of mud, and a decent amount of metal, chances are the clutches and steels are in poor shape.

Hard to say if your torque converter is the problem, or if its the victim of a problem.

You can use a scan tool to monitor the TCC slip speed. May want to find someone with a GM Tech II, or at least a GOOD scan tool to do this (a good scan tool being one that supports vehicle specific PID's, not just generic OBDII). It will probably confirm the code is legitimate, but won't tell you what's failed.

 

[RogersJetboat454]

Re: 2000 Year, Chevrolet, C3500 4L80E Transmission?

RogersJetBoat454:

No I have never done a flush on this transmission since I have owned this truck for 3 months so far. So you think I should do that? I also do not know the history on this transmission either.

NOPE!!!
Transmission flushes done routinely from the time the transmission is new makes a big difference in keeping the transmission healthy for the long run.

Transmission flushes done on a sick transmission usually make things allot worse. You would be flushing out all the thick fluid for thin, new fluid. It usually exacerbates the problem, or if things are really bad... causes the permanent "stuck in neutral" syndrome (every gear selected is neutral).

 

[gm280]

Re: 2000 Year, Chevrolet, C3500 4L80E Transmission?

I have built many TH350's and 4L60-E's in my times. Most were from the 90's and early/mid 2000's though. Almost all of them were because of a Sun Shell stripped gears. However, I never had any problems with any valve bodies from over-worn bores allowing bleed through. Most had sticking valves in the VB. Once they were removed and all cleaned up they functioned perfectly. From reading about your situation, it sounds more like a intermittent PCM connection. All the solenoids in the VB are subject to transmission fluids and the fluid does not conduct electricity at all. Otherwise no automatic transmissions would ever function. You did state that it had 126,000 miles on it and if you did a lot of towing it could indeed need a going through... Automatic transmissions are seriously not hard to rebuilt though. I would much rather rebuilt an automatic trans then a standard auto engine any day. The cost of most trans rebuild for total parts is usually less then $150-$250 dollars, the rest is labor costs. And taking the trans out and reinstalling it is the biggest part of that labor too... If your transmission is on its last leg, you could remove it and take it to have it rebuilt saving much cost... If you're even more mechanically inclined you could even rebuild it yourself and save tons of dollars...not that hard to do. If I can anybody can. There are manuals and videos to support either effort you choose... ANd there is one other option. You could simply go onto the net and research rebuilt trans for less then having yours rebuilt and install it yourself with a better warantee and better built specs as well. There are many places that only deal with trans that built them to last...

 

[CVX20SPRINT]

Re: 2000 Year, Chevrolet, C3500 4L80E Transmission?

Bubba
You need to listen to RodersJet Boat 454.He knows what he's talking about.I don't know him but I know GM trannies(did them 15 years at a dealer myself).The only thing that I would add to what he said is to rip the filter apart(open the 2 cloth halves up) when you have the pan off.If there is clutch material coming off of the plates it will mostly be in the filter.There are no quick and easy repairs on these even though they are a very tough trans.If you are having issuse with a relatively high miles tranny it's going to need to be gone right though and install a new convertor.Anything else is just prolonging the inevidable IMHO.

You keep saying it's dropping out of OD.Is it losing 4th gear(which is OD)or is the convertor coming unlocked?Big difference.

 

[Big Bubba]

Re: 2000 Year, Chevrolet, C3500 4L80E Transmission?

FatwingChris,
Well when it is in fourth gear and it does go to fourth gear it kicks out and never goes into it again until I shut the truck off for a few seconds say 15 to 20 seconds then restart the truck and I have all my gears again until it does it again after a while. /////Update////
I have found another transmission shop that has been in business since 1992 and I talked to him after work today and I am getting s second opinion from him. He said those torque convertors are pretty tough on the 4L80E and he has did alot of Sonnex transmission shift correction kits on the valve bodies with success. What he wants me to do is bring my truck down to him and he will check for FREE do a scan and a road test with my truck to see exactly what it is doing in his presence. With what I told him today he thinks more on the lines of a Sonnex shift correction kit and do some updates to the tranny if that is what he sees when the truck is in his presence he gave me a quote of approximately $400.00 with removing the valve body reaming the AFL bore in the valve body and reinstalling a Sonnex shift correction kit and the new filter and the new fluid to add to it if that is what he sees or thinks will be the right thing to do. I just DO NOT have $2,000.00 dollars lying around to do a complete rebuild and I do not have the special transmission jack or equipment to do this job myself. I just wish I could be in on the complete transmission rebuild as a helper to save money and learn at the same time but I doubt a shop would do that especially if I would get hurt at there shop and to them I would be a liability in my opinion. Thanks for your help and take care. Also, I found this in my on-line researching on the 4L80E and basically this guys 4L80E tranny is doing the same thing mine is doing after warmup. It works flawlessly like a new transmission until it gets up to temp and then that is when I lose fourth gear and kicks into third gear and does not go back into fourth until I shut my truck off for about 10 to 20 seconds and restart my truck and then shifts flawlessly into all four gears just fine. So here is what I have found on-line: just found this thread again, sorry havent been here in awhile. Buddy what ever happened with your tranny? Have you done the surecure yet? PM me if you still need the reamer.

dont know about others experience with surecure, but it absolutely worked for me. I went thru a bunch of attmepts to fix mine before finding the surecure. Initially I thought it must be the tcc solenoid and changed that. Shift solenoids, then a couple different temp senders, finally took it to the best tranny shop around, great reputation, and they told me that 4th gear was blown, and I need a tranny. Now this isnt normally the type of place to not want to help, and just sell trannies. I kept asking how it could be a broken mechanical part but still work sometimes, and they had no answer. I was actually looking at doing the torque converter next. So after online research I found the surecure, and it sounded like it fit my problem perfectly. What my problem specifically was, is that when the tranny got up to a certain exact temperature, rpms would go up and it was like losing OD. What happened was when the fluid got hot and thin enough, it was leaking by the actuator valve, causing a hydraulic pressure loss. This is because after many years of sliding back and forth in it's aluminum bore, the actuator rod ovals out the bore. So to fix it, you drop down the valve body, pull out the actuaor, bore it out with the reamer, install steel sleeve (wont happen again) then put it all back together. Of course you need to be careful, keep things clean and don't lose any small parts, but it is by no means a difficult job. I did it myself in a couple hours in my driveway, and I am not a mechanic.
I forget now how many miles its been, probably 24k or more. I've been plowing hard, towing the trailers and generally beating the snot out of the truck. Tranny is tight as a drum. All told I put under $400 into the tranny for new solenoids, sonnax kit and tool, fluid and whatever else I bought. Money well spent compared to the $3000 they wanted for a new one.

 

[CVX20SPRINT]

Re: 2000 Year, Chevrolet, C3500 4L80E Transmission?

Sounds like your new tranny guy knows what he's talking about and is on the up and up.I was going to say in the first place to get a second opinion as wellwhen I first read the post.I've never personally heard of this actuator repair,but it seems to me that it would work if you were losing 4th every time it got into 4th(which you are not if I understand you correctly).You say that if you shut it off and then restart after a few min. then all the gears work normally after that correct?That would send me more towards an electrical problem(PCM-sounds like something is resetting)) as a short stop wouldn't cool the fluid enough to stop it from bleeding by the actuator pin.If the pin bore is that bad that it's bleeding the fluid enough to loose 4th IMHO you would loose 4th everytime it made it into 4th.Good luck and keep us posted.

PS I would still be interested in how much metal and clutch material is trapped in the filter.This is a pretty good indication of the condition of the trans.

 

[Big Bubba]

Re: 2000 Year, Chevrolet, C3500 4L80E Transmission?

////////UPDATE////////
Yeap, I was able to take my 2000 Chevrolet C3500 Dually 4-door crew cab truck with 7.4 liter truck to another transmission shop to get a second opinion. We'll he looked everything over and he took his infrared thermometer gun and crawled underneath the truck to check the transmission temperature and said it was showing 140 degrees both on the infrared gun and I believe on his OTC scanner that he also hooked up underneath the dash on the drivers side. He also said that there were no codes shown at all in the computer. He also took it for a drive and I was with him on the test drive and he said it was going into TCC lockup and he tested the TCC lockup release by touching the brakes and he said the brake switch on the pedal felt right to him and it was unlocking like it was supposed to. He said that I definitely do not need a rebuild on it because to him feels good to him but he said that the valve body AFL valve might be worn somewhat causing some slip and he also said that he has replaced alot of Pressure Control Solenoids on the valve body on past transmissions. He said that he would do some more research on my issue and get back with me on it and let me know Also, I was thinking of doing a complete changeout of transmission fluid by pushing the old tranny fluid out and replace it with new tranny fluid and filter. I might replace that Pressure Control solenoid while I am at it. He said that the shifting solenoids are fine becuase if they were bad it wouldn't shift as good as it does. I might change out the TCC PWM lockout solenoid as well but he said they rarely go bad but he did say that he has swapped out alot of Pressure Control Solenoids on past transmissions. Yeap, I just talked to the guy that I had the second opinion with and he said that it will take a few days, he is so busy he said, but he is going to do up a quote to do a repair on the valve body. He definitely said the transmission does not need a rebuild just repair the valve body by installing, I think, a Transgo shift correction kit or a Sonnax, not sure which one but he was thinking the Actuator Feed Limit Valve, (AFL) is worn and will be reamed out and new sleeve and valve installed an he is also inspecting the other valves and doing updates if needed as well. Take care,Bob

 

[Big Bubba]

Re: 2000 Year, Chevrolet, C3500 4L80E Transmission?

,,,,

 

[RogersJetboat454]

Re: 2000 Year, Chevrolet, C3500 4L80E Transmission?

????

 

[Big Bubba]

Re: 2000 Year, Chevrolet, C3500 4L80E Transmission?

RogersJetBoat454,
No I don't have any questions just keeping you guys that care in the loop about my tranny issue. I do have one question though know that I think about it. Will a bad Throttle Position Sensor cause the issues I am having with my transmission acting up and kicking out of fourth gear/overdrive after the truck has warmed up. Like I said I do not have any check engine or service engine soon lights illuminated on the dash area. What do you think maybe I am grasping at straws, LOL?

 

[RogersJetboat454]

Re: 2000 Year, Chevrolet, C3500 4L80E Transmission?

A TPS is one of the contributing sensors used to calculate up-shift, and downshift. If they're glitchy, they don't always generate a fault code, but I would also think you may have more driveability concerns than just a transmission acting up.

Do you know how a TPS works?
You can easily check it with a scan tool that supports a live data stream. Pull up the PID for the TPS voltage. Throttle closed, it should read with-in the ball park of .5 volts (give or take a little). As you slowly open the throttle, the voltage should gradually, and smoothly increase up to around 5 volts ( a little under is fine) at WOT. If at any point you see the voltage drop off, or spike abnormally during the TPS sweep, than chances are your TPS has what's known as a "dead spot".

You could also do the same procedure with a volt-meter (either analog, or digital), as long as you're prepared to find and back-probe the correct wires.

Oh... any you may want to do it with the engine off (key on)...