01 Silverado 2500hd Shifting issues

[cjordan901]

Hi there! I have been trying to self diagnose an issue with my pick up for a while now and could really use some help. I have an 01 Silverado 2500HD 6.0 that shifts really hard into all gears. I was told it was the transmission going out, so we replaced the transmission with a rebuilt one and it did nothing for the shifting issues. We then had the transfer case rebuilt which also did nothing for our problems. My father who has some general mechanic knowledge is certain that the free floating rear end is not turning with the correct timing for the transmission shifting. No check engine lights come on at all during these issues. When I took it to a mechanic he told me I needed a new transmission and blew me off when I told him it was just replaced and what my dads thoughts are. I do not want to keep dumping money new transmission if its not going to fix the problem. Any insight would be appreciated!!

[j cAT]

Originally Posted by cjordan901

Hi there! I have been trying to self diagnose an issue with my pick up for a while now and could really use some help. I have an 01 Silverado 2500HD 6.0 that shifts really hard into all gears. I was told it was the transmission going out, so we replaced the transmission with a rebuilt one and it did nothing for the shifting issues. We then had the transfer case rebuilt which also did nothing for our problems. My father who has some general mechanic knowledge is certain that the free floating rear end is not turning with the correct timing for the transmission shifting. No check engine lights come on at all during these issues. When I took it to a mechanic he told me I needed a new transmission and blew me off when I told him it was just replaced and what my dads thoughts are. I do not want to keep dumping money new transmission if its not going to fix the problem. Any insight would be appreciated!!

harsh upshifting is when the PCM senses a slippage of the transmission. so if the speed sensors are reporting one speed and the tranny another the PCM commands max fluid pressures to reduce slippage.

your vehicle has a computer that stores all this stuff.my guess is you had some idiots rip you off by selling you transmissions. what this means is the proper scan tool with GM specific code ability will show all this stuff. no not a 100USD scan tool but a 2500 USD GM code reader tool .

your truck should have a locking rear differential. gearing should not effect shifting harshness...if in 2wd the diff just rolls along.

[cjordan901]

Originally Posted by j cAT

harsh upshifting is when the PCM senses a slippage of the transmission. so if the speed sensors are reporting one speed and the tranny another the PCM commands max fluid pressures to reduce slippage.

your vehicle has a computer that stores all this stuff.my guess is you had some idiots rip you off by selling you transmissions. what this means is the proper scan tool with GM specific code ability will show all this stuff. no not a 100USD scan tool but a 2500 USD GM code reader tool .

your truck should have a locking rear differential. gearing should not effect shifting harshness...if in 2wd the diff just rolls along.

Ok so I went out and bought a transmission vehicle speed sensor however when I pulled the old on off, they are completely different. The Napa guy assured me that I got the part I was looking for but the two look nothing alike. The new one has an elbow shape to it with a metal harness and the old one is straight with no metal attached. The old one looks similar to the wheel speed sensor is it possible that they could be switched or do I definately have the wrong part? How do I tell?

[j cAT]

Originally Posted by cjordan901

Ok so I went out and bought a transmission vehicle speed sensor however when I pulled the old on off, they are completely different. The Napa guy assured me that I got the part I was looking for but the two look nothing alike. The new one has an elbow shape to it with a metal harness and the old one is straight with no metal attached. The old one looks similar to the wheel speed sensor is it possible that they could be switched or do I definitely have the wrong part? How do I tell?

I would look up the part you need at rock auto parts. see what the part looks like and the part number. if the part looks wrong and the connector is not correct it is wrong. I would also use a OHM METER and measure the both sensor resistance.

I would also measure the amount of sensor depth that it would set into the tranny.

many times these part guys will give you the wrong part ..use the internet to find this info first before going to your local store.. advance auto/ auto zone also use to see what is the correct part as the have part numbers and pictures... with the correct part number then stores can use the data base to check for compatibility of other manufacturer made parts.