Speedo sensor location on Allison tranny

[poppagar]

Can anyone tell me where the speedometer sensor is on a 2018 Silverado Duramax w/Allison tranny. I need to recalibrate the speedo because I installed larger tires and my speedo is way off.  I'm thinking about using a "Yellow Box"  to recalibrate the speedometer but I'm not sure exactly where the sensor plug is. It's supposed to be on the side of the transmission but I don't want to disconnect anything until I'm sure of what I'm doing.

Any help would be appreciated.

[Vice305]

2 hours ago, poppagar said:

Can anyone tell me where the speedometer sensor is on a 2018 Silverado Duramax w/Allison tranny. I need to recalibrate the speedo because I installed larger tires and my speedo is way off.  I'm thinking about using a "Yellow Box"  to recalibrate the speedometer but I'm not sure exactly where the sensor plug is. It's supposed to be on the side of the transmission but I don't want to disconnect anything until I'm sure of what I'm doing.

Any help would be appreciated.

I think you best bet would be to get a hand held programmer though like superchips

[poppagar]

I am going to get a tuner/programmer instead of the "Yellow Box" which BTW is made in Australia. I guess that have a 

distributer somewhere in the US but I decided to take your advise and buy a programmer instead.

Thanks for the advise.