'96 gmc sierra speed buffer?

[Jorge6.5]

What is the purpose of the speed buffer?

If it goes bad what are the symptoms?

Where can I source a new or working unit?

 

[Burning oil]

If I remember it converts the signal so ECM and Speedo can use it.
Junk yard time.

 

[Big T]

If I remember it converts the signal so ECM and Speedo can use it.
Junk yard time.

It's called a VSSB or Variable Speed Sensor Buffer. Leroy is correct, it coverts or adjusts the signal from the transmission so the speedo reads accurately. Basically, every transmission sender emits the same signal and the VSSB is used to adjust it to the specific set-up of the vehicle. It adjusts for tire size, gear ratios, etc. the VSSB will have a series of Dip switches that are flipped to adjust to the specifics of the vehicle. Any speedo shop can adjust one to fit your vehicle set-up within a range. That said, the one on my son's '94 Burb could not be adjusted to within more than 9% of accuracy, so they had to add an adapter to bring his readout within accuracy.

BTW, I have a working VSSB from a '95 Burb with 4.10 rear end. Pay me USPS parcel rate and it's yours.

 

[THEFERMANATOR]

VSSB= vehicle speed sensor buffer. It converts the AC signal of the vehicle speed sensor from the 40 tooth per revolution output to a 2000 pulse per mile signal for the ECM and radio(for 95+ trucks), and it also makes the 128,000 pulse per mile signal that the ABS needs. it has jumpers oldered in from the factory to adjust the speed ofor gear ratio and tire sizes, but you can remove the jumpers and add in dip switches to make it easily adjusteable. If it fails your speedo will stop working, or it could fail and cause the speedo to read wrong.

 

[Jorge6.5]

Even though the '95 is obdI, will it work an obdII truck?

Thanks much for the replies guys. This is on going problem that I have been having since the t case swap I made, button t case to lever t case

 

[THEFERMANATOR]

Yes, the 95 VSSB will work in your 96 diesel(96+ gassers don't use them).