Max Power
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The information in this post is for information purposes only. I hold no responsibility for any damage to your vehicle, yourself or others. Do not attempt this on vehicles that do not have the proper speed rated tires.
I figured out how to remove the top end speed limiter on all 01,02, and 03's with the Allison. It is a very easy mod and can be done in less then 30 minutes. It is also cheap $0-$10. Unfortunately it has side effects.
The side effects are:
1) No speedo however your Attitude will still read your speed!
2) Service Brake system warning will turn on. This inclues 'service brake system' on the DIC as well as the park brake light and ABS light will be illuminated. You will also hear a very loud chime for about 30 seconds.
3) You will have no ABS Brakes.
4) There will be a code stored
5) You will have no cruise control
6) You may get a speeding ticket.
What you need to do is remove the 2 bolts holding the TCM in place. The bottom plug is the plug we need to work with. Unplug it from the TCM. In Pin position 27 you will see a yellow wire. You have 3 choices.
1) You can either remove that wire from the TCM altogether. This will remove your speed limiter until you put the wire back in position. This will also come with all the side effects above until you plug it back in.
2) You can cut the wire and splice in 2 wires, run them into the cab and hook those 2 wires to a switch. This will allow you to turn it on and off as you choose. The only problem with this is you will have a cut wire to deal with later on.
3) You can get a pin from your GM dealer as it is the same pin as used for the high idle. Remove the yellow wire and find a way to afix a wire to that pin once it is removed. Then put your new pin and wire into the hole that you removed the yellow one. Run both wires into the cab and hook up a switch same as above.
Thats it! The transmission seems to shift normally. You can take it right up to red line in 5th gear. Your attitude will display the proper speed so you know how fast you are going. If you run switch into the cab you can easily turn it on or off as you need it. Once you turn it back on you will have full funtion of everything as normal.
There might be some other side effects as I only tested it for a few miles Use at your own risk. I am not responsibe for any damages.
I had my truck up to 110 mph but I had to back off because there was too much traffic ahead.
I haven't tested this on an 01 but the schematic is the same and it should have the same effect.
I figured out how to remove the top end speed limiter on all 01,02, and 03's with the Allison. It is a very easy mod and can be done in less then 30 minutes. It is also cheap $0-$10. Unfortunately it has side effects.
The side effects are:
1) No speedo however your Attitude will still read your speed!
2) Service Brake system warning will turn on. This inclues 'service brake system' on the DIC as well as the park brake light and ABS light will be illuminated. You will also hear a very loud chime for about 30 seconds.
3) You will have no ABS Brakes.
4) There will be a code stored
5) You will have no cruise control
6) You may get a speeding ticket.
What you need to do is remove the 2 bolts holding the TCM in place. The bottom plug is the plug we need to work with. Unplug it from the TCM. In Pin position 27 you will see a yellow wire. You have 3 choices.
1) You can either remove that wire from the TCM altogether. This will remove your speed limiter until you put the wire back in position. This will also come with all the side effects above until you plug it back in.
2) You can cut the wire and splice in 2 wires, run them into the cab and hook those 2 wires to a switch. This will allow you to turn it on and off as you choose. The only problem with this is you will have a cut wire to deal with later on.
3) You can get a pin from your GM dealer as it is the same pin as used for the high idle. Remove the yellow wire and find a way to afix a wire to that pin once it is removed. Then put your new pin and wire into the hole that you removed the yellow one. Run both wires into the cab and hook up a switch same as above.
Thats it! The transmission seems to shift normally. You can take it right up to red line in 5th gear. Your attitude will display the proper speed so you know how fast you are going. If you run switch into the cab you can easily turn it on or off as you need it. Once you turn it back on you will have full funtion of everything as normal.
There might be some other side effects as I only tested it for a few miles Use at your own risk. I am not responsibe for any damages.
I had my truck up to 110 mph but I had to back off because there was too much traffic ahead.
I haven't tested this on an 01 but the schematic is the same and it should have the same effect.
