RobH
Full Access Member
Hi. I need advice.
Situation: 2016 two wheel drive Tahoe with a 6L80E and the Max Trailering package.
I bought the Tahoe three years ago with 80,000 miles and have put 40 thousand miles on it. It now has 123,000 miles. I had the pan dropped and the fluid and filter changed at 90,000 miles. I have pulled a 3,300 pound Casita Travel Trailer about 10,000 miles with it. The trailer weight is based on weighing ready to depart on a trip. No idea what the previous corporate owner did with the Tahoe. I do not have the trailer on my current trip.
Earlier on my current trip, I filled the tank with fuel. Immediately thereafter I experienced a hard shift from 1st to 2nd followed by jerking. I immediately pulled over to check the transmission fluid level and it was correct and the fluid looked reddish, not brown. By feathering the throttle I was able to get it to drive to a motel. I thought bad fuel. But, I noticed that when I put it in Reverse, it didn't do anything and then engaged with a clunk.
Running at 60 miles per hour in fifth and 2000 RPM on the level, the torque converter seems OK. But when I go up a hill, the RPM increases. So I figure a slipping torque converter lockup clutch. So, I back off on the accelerator when going up hills to prevent the RPM from increasing.
I took it to a NAPA shop and they said there were no codes, but observed the hard shifting and shuddering. They used their controller to command the lockup to not occur, and the shifts were smooth with the usual smooth overall operation, albeit without the lockup, fluid coupling only.
They said that flushing the fluid "might" improve things if I wanted to spend the money on it. They said the fluid they removed from it had fine pieces of metal, "sparkles" under light, in it.
Initially it was a little bit better, but it deteriorated. The 4th to 5th shift occurs at the usual RPM when the transmission temperature is below 170F but is delayed when the temp is above 180F. The temp is between 180 and 195 when warmed up. I've never seen a temp above 200F. Usually it is 185 or less.
I am limping home using fifth gear for cruising and modulating the accelerator pedal to prevent or minimize torque converter clutch slippage. All gears are now hard engaging except for first thing in the morning when the fluid is warming up. When above 180F, I have to rev it up to 3,000 RPM and 70 MPH, and then back off the accelerator pedal abruptly to get it to upshift from fourth into fifth.
Initially I had about 2,500 miles to get home. For the first seven or eight hundred miles, there were no Check Engine Lights. Since then I have had four or five CEL's in the last couple of days. I have a Scan Gauge II and check the codes and then clear them. The throwing of the codes normally is associated with one of the delayed upshifts from fourth to fifth. Most of the code combinations have been a P0700 with a B2AAA. Once there was a P0741 with a B2AAA.
I understand the premise that a re-manufactured transmission may or should have upgraded parts in the torque converter and elsewhere to prevent known problems. I will also change the fluid as specified in the "Maintenance Schedule - Additional Required Services - Severe" schedule. I have no information on whether the fluid was ever changed before I bought the Tahoe with 80,000 miles on it.
Do I conclude that the transmission is toast and get a GM or Jasper re-manufactured transmission to have something that will last for another hundred thousand or more miles without interrupting a trip on me? Do I get it "repaired" with a shorter warranty?
The Owner's Manual says to drain the fluid and replace the filter, which requires dropping the pan. Flushing the fluid does not allow changing the filter. Is it better to
1. drain and refill including changing the filter or is
2. a "100% change of the fluid" by flushing better?
I can drain the fluid at home a lot more cheaply than at an oil change shop and may just do it every other year depending on whether that is the recommended way to change it. I'm not set up for a "100% flushing".
Regardless, I will ensure that a TSB 70 Centigrade Thermal Bypass Valve goes in. I wish I had known about it when I did the fluid and filter change 30,000 miles ago.
Thank you all in advance for sharing your knowledge. Rob
Situation: 2016 two wheel drive Tahoe with a 6L80E and the Max Trailering package.
I bought the Tahoe three years ago with 80,000 miles and have put 40 thousand miles on it. It now has 123,000 miles. I had the pan dropped and the fluid and filter changed at 90,000 miles. I have pulled a 3,300 pound Casita Travel Trailer about 10,000 miles with it. The trailer weight is based on weighing ready to depart on a trip. No idea what the previous corporate owner did with the Tahoe. I do not have the trailer on my current trip.
Earlier on my current trip, I filled the tank with fuel. Immediately thereafter I experienced a hard shift from 1st to 2nd followed by jerking. I immediately pulled over to check the transmission fluid level and it was correct and the fluid looked reddish, not brown. By feathering the throttle I was able to get it to drive to a motel. I thought bad fuel. But, I noticed that when I put it in Reverse, it didn't do anything and then engaged with a clunk.
Running at 60 miles per hour in fifth and 2000 RPM on the level, the torque converter seems OK. But when I go up a hill, the RPM increases. So I figure a slipping torque converter lockup clutch. So, I back off on the accelerator when going up hills to prevent the RPM from increasing.
I took it to a NAPA shop and they said there were no codes, but observed the hard shifting and shuddering. They used their controller to command the lockup to not occur, and the shifts were smooth with the usual smooth overall operation, albeit without the lockup, fluid coupling only.
They said that flushing the fluid "might" improve things if I wanted to spend the money on it. They said the fluid they removed from it had fine pieces of metal, "sparkles" under light, in it.
Initially it was a little bit better, but it deteriorated. The 4th to 5th shift occurs at the usual RPM when the transmission temperature is below 170F but is delayed when the temp is above 180F. The temp is between 180 and 195 when warmed up. I've never seen a temp above 200F. Usually it is 185 or less.
I am limping home using fifth gear for cruising and modulating the accelerator pedal to prevent or minimize torque converter clutch slippage. All gears are now hard engaging except for first thing in the morning when the fluid is warming up. When above 180F, I have to rev it up to 3,000 RPM and 70 MPH, and then back off the accelerator pedal abruptly to get it to upshift from fourth into fifth.
Initially I had about 2,500 miles to get home. For the first seven or eight hundred miles, there were no Check Engine Lights. Since then I have had four or five CEL's in the last couple of days. I have a Scan Gauge II and check the codes and then clear them. The throwing of the codes normally is associated with one of the delayed upshifts from fourth to fifth. Most of the code combinations have been a P0700 with a B2AAA. Once there was a P0741 with a B2AAA.
I understand the premise that a re-manufactured transmission may or should have upgraded parts in the torque converter and elsewhere to prevent known problems. I will also change the fluid as specified in the "Maintenance Schedule - Additional Required Services - Severe" schedule. I have no information on whether the fluid was ever changed before I bought the Tahoe with 80,000 miles on it.
Do I conclude that the transmission is toast and get a GM or Jasper re-manufactured transmission to have something that will last for another hundred thousand or more miles without interrupting a trip on me? Do I get it "repaired" with a shorter warranty?
The Owner's Manual says to drain the fluid and replace the filter, which requires dropping the pan. Flushing the fluid does not allow changing the filter. Is it better to
1. drain and refill including changing the filter or is
2. a "100% change of the fluid" by flushing better?
I can drain the fluid at home a lot more cheaply than at an oil change shop and may just do it every other year depending on whether that is the recommended way to change it. I'm not set up for a "100% flushing".
Regardless, I will ensure that a TSB 70 Centigrade Thermal Bypass Valve goes in. I wish I had known about it when I did the fluid and filter change 30,000 miles ago.
Thank you all in advance for sharing your knowledge. Rob
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