4L80e - low RPM vibration when converter is locked up
#11
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When you go into lockup do you have full lockup or that partial engaged PWM bull crap that lets the converter slip a little? I know on the half tons that have this they reach full lockup at around 55 mph but a 3/4 ton may be different. Sounds to me like you are getting some converter clutch shudder. I've replaced two converters because of this. One was in a 05 half ton Sierra and the other in a GMC Acadia of all things. On both I could watch the slip speed and when it started the shuddering it would be all over the place as high as 150 and as low as 0. Once it hit full lockup it held fine and there was no more shuddering. At the speeds you are saying I think this may be kind of a stretch but its worth looking at if you have the scan tool to view your slip speed.
Are you sure you don't have an ignition related misfire? You usually get those right around 55-75 light load cruising speed when the mixture is kind of lean and the load is kind of high like pulling a hill and that weak little spark can't quite make the big bang happen.
Are you sure you don't have an ignition related misfire? You usually get those right around 55-75 light load cruising speed when the mixture is kind of lean and the load is kind of high like pulling a hill and that weak little spark can't quite make the big bang happen.
#14
no vibrations in 1st or 2nd . . . .
I only get the vibrations when it's locked in 3rd and 4th
I ordered the valve body repair kit, but I ended up getting the refill kit vs the new drill/reamer and new valves . . . I'll have to wait for another week.
I only get the vibrations when it's locked in 3rd and 4th
I ordered the valve body repair kit, but I ended up getting the refill kit vs the new drill/reamer and new valves . . . I'll have to wait for another week.
#15
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Had the same problem with my 2500HD 2 years ago and it ended up being a bad converter. Replaced it with an OEM spec replacement along with a new filter/oil......still going strong with over 200K miles.
I'm not saying this is the case but you might want to double check before dropping a lot of coin on more parts.
-Isaac-
I'm not saying this is the case but you might want to double check before dropping a lot of coin on more parts.
-Isaac-
#17
I still have a clanging metallic dragging noise that's going on while in park or in neutral. The oil is still clean, even after I got my truck back from being stolen.
#19
Needless to say I was embarrassed that it was as simple as an injector adapter
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