Jump to content

4L80E problems

bigirondog
 Share

Recommended Posts

bigirondog Enthusiast

bigirondog

Posted
Posted

I have a 06 GMC 2500HD 4x4 6.0 4L80E 4:10.. 85,500 milage.....

 

my issue is the torque converter will unlock at random at about 70 mph.

I can pull a trailer with a heavy load and stay under 70 mph and all is great. power is good. however with NO load and level ground the torque converter unlocks and will not lock back up until I slow down to below 65 mph.

 

NO CODES.....

I have extra parts from other trucks to which I have changed the throttle position sensor, throttle body, ECU on the firewall under the hood, and the torque converter lock up in the trans. also changed the fluid, added lucas all with no change.

it takes it a long time to lock up when its cold, first thing of a morning.

 

this truck does great under a load or empty as long as I stay below 70 mph.

using the cruise or with out, no change.

 

any suggestions as to where to look and what at would be great.

 

 

 

Grumpy Tooch Enthusiast

Grumpy Tooch

Posted
Posted

@ about 75000mi I had problem with my tranny over heating. I had to have the TC replaced, along with all the lines too. They told me it was common with 4l80e

bigirondog Enthusiast

bigirondog

Posted
  • Author
Posted

I have owned it since 45,000 miles......I never drove it on the interstate or got above 70 until a year ago.

 

the temp guage never gets hot, trans seems to run cool. I replaced the stock cooler with a larger trans cooler.

 

it does this when its cold also. first thing of a morning takes a long time for TC to lockup.

ZachM1 Enthusiast

ZachM1

Posted
Posted

I had a similar issue with my 4l80e. Put a larger cooler on it and the same thing happened.

There is a temperature sensor in the transmission. When the trans fluid goes below a certain temp, torque converter lockup is canceled. When the temp goes above that temp, it is re-enabled.

When your torque converter is in lockup mode, the transmission is in a "cooling and overdrive planetary lube" mode.

 

With the larger cooler it is going below the temperature range that allows this when in lockup.

 

Not going into lockup with the 4l80e due to over cooling will not damage anything. It will just affect your mpg.

gmtech4 Senior Enthusiast

gmtech4

Posted
Posted (edited)

I had a similar issue with my 4l80e. Put a larger cooler on it and the same thing happened. There is a temperature sensor in the transmission. When the trans fluid goes below a certain temp, torque converter lockup is canceled. When the temp goes above that temp, it is re-enabled. When your torque converter is in lockup mode, the transmission is in a "cooling and overdrive planetary lube" mode. With the larger cooler it is going below the temperature range that allows this when in lockup. Not going into lockup with the 4l80e due to over cooling will not damage anything. It will just affect your mpg.

 

 

what ?,where did ya get that info ? i must check my blue book if i can find it lol

Edited by govtech4
ZachM1 Enthusiast

ZachM1

Posted
Posted

 

 

what ?,where did ya get that info ? i must check my blue book if i can find it lol

 

Oh just being a transmission specialist / rebuilder for well over a decade.

scooby5121 Enthusiast

scooby5121

Posted
Posted (edited)

Mine always unlocks on hills, pulling or not.

Scooby

 

Hot or Cold.....

Edited by scooby5121
Badass69 Senior Enthusiast

Badass69

Posted
Posted

Yeah but locking and unlocking at random is not normal. The most annoying thing I found was the wide open throttle lockup in 2nd gear that the 80E's do.... dumb. So neither of mine have that ability anymore lol.

 

I was convinced my 04's transmission was toast. My convertor would lock and unlock at random.... wouldn't unlock properly etc. Then the trans itself shifted really hard ( line pressure was maxing), hang up in gears etc... I had no codes, nothing that really stood out. So because I have parts I swapped the 3 things one at a time enginewise I thought it could be, being my throttle body ( so I got a known good tps), map sensor and MAF sensor. Low and behold it was my MAF... Now I have scanning software and I had very odd fuel trims at idle, random knock retard at WOT etc. The truck ran well enough and never did anything weird that without seeing the data no one would have noticed the engine issues ever.

 

It's worth a look anyhow. I have had a check engine light or anything either, and if the OP has parts to swap since you tried the throttle body give the mass airflow and map sensors a try.

  • Like 1
97CAIVIAROSS Enthusiast

97CAIVIAROSS

Posted
Posted

I didn't have the exact same symptoms as you but mine would lock then unlock and not lock again on the highway. Did some reading on this site and the solution to mine was a crank position sensor relearn. Did they with a SnapOn scanner believe it was a Modus and all is good now.

Grumpy Tooch Enthusiast

Grumpy Tooch

Posted
Posted

I have a 06 GMC 2500HD 4x4 6.0 4L80E 4:10.. 85,500 milage.....

 

my issue is the torque converter will unlock at random at about 70 mph.

I can pull a trailer with a heavy load and stay under 70 mph and all is great. power is good. however with NO load and level ground the torque converter unlocks and will not lock back up until I slow down to below 65 mph.

 

NO CODES.....

I have extra parts from other trucks to which I have changed the throttle position sensor, throttle body, ECU on the firewall under the hood, and the torque converter lock up in the trans. also changed the fluid, added lucas all with no change.

it takes it a long time to lock up when its cold, first thing of a morning.

 

this truck does great under a load or empty as long as I stay below 70 mph.

using the cruise or with out, no change.

 

any suggestions as to where to look and what at would be great.

 

 

 

I have the same truck same mileage and I had the same problem 6 months agohad to have the dealership replace a torque converter and all the lines going to the raditormy issue was is that the transmission was overheating

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing

  • Latest Articles

  • Posts

    • PunchT37
      OCI, not when but why?

      By PunchT37 · Posted

      When I was there, most to all did not have an hour meter. They just did 5000 miles on regular vehicles and 3000 on police stuff. The modern oil change monitors should take into account engine hours, weather, etc. I don`t use the monitor on my stuff. I pull the stick, look at it, smell it, rub it between my fingers, etc. That`s my oci.   I have had many engines. Some bracket race. No problems doing things my way. I was in the mechanic business for 30 yrs or so. I still do things the old school way. Don`t care who laughs at me.   Understand, I was in the main shop. We didn`t do oil changes or tires. We had a service station for that. I don`t remember the hours they used for tractors, lawn mowers, etc. Something in my head says 250 hours.
    • Chuck FB
      OCI, not when but why?

      By Chuck FB · Posted

      I don't know how far back vehicles had hour meters, be it driver accessible or diag accessible but was wondering if there was any rule of thumb your shop came up with in regards to an hour limit on engine oil regardless of the miles on the oil.    I know with construction or farm equipment its almost always based on engine hours for maintenance scheduling as no other metric really applies other than a seasonal time limit that one self imposes on items like engine oil.  
    • Chuck FB
      OCI, not when but why?

      By Chuck FB · Posted

      I'm not sure what to say on that mess but I will say that is an odd thing for that mechanic to speculate on as per assuming its been run out of oil a few times as the odds of that engine having instead piled up with a complete seizure would be very high if such events had actually taken place. However there is nothing saying that the oil has ever been changed although once again, what filter was on that engine as that would tell part of the story if its possible to figure out if its a factory installed filter or not. Too many items unknown and a lot of speculation, but regardless of that its one fubared mess that is mind boggling to see for a vehicle that new and its hard to imagine how it ever made it that far in life looking at the top of the engine.    His scanners, I've watched him before here and there and I'd have to say if I recall correctly that some of his scanning equipment is one or two steps up from a child's Exo Sketch 😋
    • PunchT37
      OCI, not when but why?

      By PunchT37 · Posted

      I agree. That`s a LOT of sludge for 12,000 miles. I tossed that out here since this is an OCI thread. There`s tons of people here that do not post.   I used to work on a city fleet. That includes police cars and fire trucks. Lesson is, not to only use the odo for oci. A police car has a ton of hours on the engine for the miles it shows. And, not just idling, directing traffic. They beat on these things.   Course, since it is a Kia, they were gonna use the "100,000 mile warranty" for their OCI.😉
    • AlVeron
      Manufactuer's Defect - Paint Failure - Cherry Red High Country 2021 Suburban

      By AlVeron · Posted

      CLASS ACTION SUITS?  Does anyone know if there is already a class action suit for the paint - which was to have been fixed, changed in after the 2020 GM vehicles?  Does it look like this?    Just started 3 weeks ago - No help from GM as of yet - Dealer will not assist in speaking with GM on my behalf. Confirmed it is the paint they use along with the way the put it on that causes it to fail.  Clearly a Manufacturer's Defect. 

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...