4L60E Transmission struggling to shift into Overdrive?

I have a 96 gmc k1500 with the 5.0 and 4L60E. It drives and shifts perfectly other than recently, after its warmed up it seems to struggle to shift into overdrive. It will get stuck at 2000 rpm and even if I put the pedal on the floor it will not rev any higher. Its not my fuel pump or filter as they are brand new. I also have a brand new MAF sensor and speed sensor. When it is stuck at 2000rpm it will almost gurgle or stutter. I honestly have no idea what it could be other than maybe needing a rebuild. I also have no codes.

RyleeBoh said:

I have a 96 gmc k1500 with the 5.0 and 4L60E. It drives and shifts perfectly other than recently, after its warmed up it seems to struggle to shift into overdrive. It will get stuck at 2000 rpm and even if I put the pedal on the floor it will not rev any higher. Its not my fuel pump or filter as they are brand new. I also have a brand new MAF sensor and speed sensor. When it is stuck at 2000rpm it will almost gurgle or stutter. I honestly have no idea what it could be other than maybe needing a rebuild. I also have no codes.

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It will not upshift into 4th at all; stays in 3rd gear or it does upshift and feels like it's in neutral?

Check fluid condition and smell. Not sure what "gurgle" means but if by "stutter" you mean to say "slip", the 3-4 clutch pack and/or band is shot and it needs to come out for overhaul.

If 4th gear only, check servo piston apply by dropping the pan and putting compressed air into the little exhaust port on the pan rail surface right under the servo bore to see if you have band apply. If so, 4th gear servo sealing ring is in good shape and thus not the problem.

To know for sure what the trans and ecm are actually doing, connect a bi directional scan tool, fire it up and take for a drive with live transmission data being displayed. Look to see what gear is being commanded/what gear the exm thinks the trans is in and compare that to what gear it's in based on your count of upshifts.

ETA: what brand of speed sensor and MAF? Should be OEM/AC Delco for the speed sensor and OEM (Delphi, I think) for the MAF.

RyleeBoh said:

I have a 96 gmc k1500 with the 5.0 and 4L60E. It drives and shifts perfectly other than recently, after its warmed up it seems to struggle to shift into overdrive. It will get stuck at 2000 rpm and even if I put the pedal on the floor it will not rev any higher. Its not my fuel pump or filter as they are brand new. I also have a brand new MAF sensor and speed sensor. When it is stuck at 2000rpm it will almost gurgle or stutter. I honestly have no idea what it could be other than maybe needing a rebuild. I also have no codes.

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I'm experienceing the same thing with my 97 5.7 it does the exact thing

I have done some research and I have found my trani will most likely need a rebuild.

RyleeBoh said:

I have a 96 gmc k1500 with the 5.0 and 4L60E. It drives and shifts perfectly other than recently, after its warmed up it seems to struggle to shift into overdrive. It will get stuck at 2000 rpm and even if I put the pedal on the floor it will not rev any higher. Its not my fuel pump or filter as they are brand new. I also have a brand new MAF sensor and speed sensor. When it is stuck at 2000rpm it will almost gurgle or stutter. I honestly have no idea what it could be other than maybe needing a rebuild. I also have no codes.

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I had to do this with mine for about 6 or so years now! Manualy shift it on the column and when towing heavy loads don't use cruise control because you just throwing fuel right out of the exhaust!!

so did you get the transmission inspected? What was found? Did they rebuild it? I hope it is better now for you!

I never did find out the Issue and it still does it. Same transmission and no rebuild. I think it is something with the motor. It shutters like its slipping but on an extreme scale. Almost like it is losing power randomly and starts stalling. The Trani shifts flawlessly driving around town and when she is hot she shifts a bit hard from 1st-2nd but I believe that is unrelated. Its got good fuel pressure and runs very good. It only happens when ive been driving 65mph+.

RyleeBoh said:

It will get stuck at 2000 rpm and even if I put the pedal on the floor it will not rev any higher.

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That doesn't sound like a transmission problem,sounds like an engine problem. First thing I would be checking would be a clogged catalytic convertor, the second would would be fuel pressure. Just because a fuel pump is new doesn't mean it's any good.