July 22nd, 2015, 2:34 PM
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4L80 transmission problems
February 12th, 2014, 10:48 AM
#11
Is anyone now or in the past had a problem with their reverse gear barely or in a bumpy fashion move their vehicle to only creep along at first then finally gain momentum but not without much protest from somewhere.It is difficult to feel where the problem is directly coming from.This is a"95" Tahoe with 190,000 miles but otherwise runs like a champ.No otherdrive issues, not even play in u-joints.
Allan
July 13th, 2014, 2:14 PM
#12
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overdrive issue
I have a 2002 silverado that in the morning i have overdrive for about 15 mins and once i slow down to where it shifts out of overdrive it doesnt go back into it. even after it has sat at work for 8 hours i still dont get it back until the next morning. any ideas what it might be?
October 28th, 2014, 3:35 PM
#13
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I also have a 2000 model chevy, 2500 series with 4L80E transmission with 80K miles.
I could start out in the morning, transmission oil cold, and it worked fine for about 5-6 miles or even further if I stayed on level roads.
If I came to a hill it would shift out of OD 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, transmission would shift into OD after the stop until I got to the next hill. Sometimes, it would shift out of OD on level road.
GM Tech said in time it would get to the point that it would no longer shift into OD at all.
Tech said the reason for the hard shift, 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 transmission would not shift into OD, all shifts were very hard/jerky shifts like it had a shift kit installed).
He said some type piston in torque converter was busted/cracked and would not allow the torque converter to maintain the proper oil pressure to stay in the lockup position.
All I know, is a new torque converter fixed the problem, just a mechanical failure.
Tech said GM changed thetorque converters in the 2000 models, had a number of failures and changed back to the old setup. Again, do not know if this is true, but a$1000 torqure converter replacement fixed the problem.
Good luck with yours, hope you come out better.
I could start out in the morning, transmission oil cold, and it worked fine for about 5-6 miles or even further if I stayed on level roads.
If I came to a hill it would shift out of OD 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, transmission would shift into OD after the stop until I got to the next hill. Sometimes, it would shift out of OD on level road.
GM Tech said in time it would get to the point that it would no longer shift into OD at all.
Tech said the reason for the hard shift, 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 transmission would not shift into OD, all shifts were very hard/jerky shifts like it had a shift kit installed).
He said some type piston in torque converter was busted/cracked and would not allow the torque converter to maintain the proper oil pressure to stay in the lockup position.
All I know, is a new torque converter fixed the problem, just a mechanical failure.
Tech said GM changed thetorque converters in the 2000 models, had a number of failures and changed back to the old setup. Again, do not know if this is true, but a$1000 torqure converter replacement fixed the problem.
Good luck with yours, hope you come out better.
October 31st, 2014, 6:55 AM
#14
Hello,
Code P1870 means transmission component slipping, this code is usually sets because of a problem with lock-up. Which could mean converter,pump or stator bushing, rings,valvebody or solenoid. If you have a good scanner sometimes you can look at rpm slip when the computer commands lock up. I see the code set after a long drive on the parkway, thats usually when the computer sees the slip. Gary
Code P1870 means transmission component slipping, this code is usually sets because of a problem with lock-up. Which could mean converter,pump or stator bushing, rings,valvebody or solenoid. If you have a good scanner sometimes you can look at rpm slip when the computer commands lock up. I see the code set after a long drive on the parkway, thats usually when the computer sees the slip. Gary
November 4th, 2014, 11:04 AM
#15
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thank you Gary last week i had the torque converter taken out and opened up the torque converter and found that the TCC torque converter clutch was busted up pretty bad thats what was causing the slippage because the guy who had it before me like a moron towed up hills with out the towing package which tell the computer not to go into OD while its on (GM tech told me that) so with a new torque converter it runs great now no more slippage.
if any one out there that tows/ hauls big loads remember if you have a automatic please make sure you turn on the towing package or use the gears that are there and do not let it go into OD for the life time of the torque converter is lessened by half
if any one out there that tows/ hauls big loads remember if you have a automatic please make sure you turn on the towing package or use the gears that are there and do not let it go into OD for the life time of the torque converter is lessened by half
March 12th, 2015, 9:49 AM
#17
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When the transmission begins getting too warm the transmission "clunks" between gears to prevent slippage and further damage. The torque converter clutch(TCC) most likely failed. The debris collects in the tranny cooler and causes further overheating. A solenoid or fluid change will most likely do nothing but cost $ for nothing. My truck has been to 5 GM mechanics in 3 days and they have ALL confirmed this. My torque converter will be replaced today as well as a tranny flush and filter change and I will see if this fixes it. $2000 for this so I have my fingers crossed.
March 12th, 2015, 10:06 AM
#18
If i may put my 2 cents in, i have a trans shop in new york, Did you confirm a bad converter, did you see the rpm slip, these transmissions have more issues than just the converter. Im in new york i get 2000 wholesale price for a complete overhaul with a converter. Gary
April 12th, 2015, 4:04 PM
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I have a 2000 chevy silverado 2500 6.0Lwith only 115000kms on it over the last couple monthsthe4L80 transmission hasbeenhaving really hard shifts after drivingon the highway for 30-40 min in D4 the engine light comes on and the code p1870 comes up on the code reader i had the chevy dealershipreplace the solonoidand pressure valveflush out everything and 700 bucks later i still have the problem they said i need a new tranny i took my truck to a transmission shop they installed a regulatorand said there was a littleblack soot in the valve body and is hinting towards a new torque convertor but with noguarantee to fix the problemand once again 550 bucks later SAME PROBLEM if there is anyone out there who could shoot me some good advice would be awesome
April 13th, 2015, 10:03 PM
#20
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4L80E 1st gear hardshift
I don't know if this is a big issue or just a simple tranny flush, but I am having some interesting shift issues from 1st gear to 2nd gear. Granted, 1st gear in any automatic is prone to going before any other gear because, well it's 1st gear! Anyways, it doesn't matter if I left the truck warm up or drive cold (which I'd advise never to do if you can help it), but for some reason 1st gear will be hard and slow to move thru and then after climbing to 2500RPM or 3000RPM some days, she'll shift to 2nd and be fine after that with no problems.
I am just wondering if again if this is something I should be worried about OR I just need a tranny flush. Personally, I don't wanna replace my damn tranny, I'd rather just do a flush and filter change (if needed).
Anyone got an idea?
EDIT 1: My mileage is at 165,xxx now and it has been happening since I bought the truck. Don't know if this is normal for a high mileage 4L80E.
I am just wondering if again if this is something I should be worried about OR I just need a tranny flush. Personally, I don't wanna replace my damn tranny, I'd rather just do a flush and filter change (if needed).
Anyone got an idea?
EDIT 1: My mileage is at 165,xxx now and it has been happening since I bought the truck. Don't know if this is normal for a high mileage 4L80E.
Last edited by blckdragn22; April 13th, 2015 at 10:05 PM. Reason: Missing info.