Just got done installing a water pump and my code scanner just showed up. So I pulled a code from continuous memory 452 vss signal fault. I'm sure this would contribute to my hard/erratic shift problem. My question is where do I start? Already changed the vss on the diff. What's next wire, tone ring, bearings?

 

I will ask this: Did you clear the codes after you replaced the VSS?

 

Yes I have disconnected the battery several times. If I disconnect the battery the hard shifting will go away for alittle bit then ill drive it for a bit and it comes back along with not shifting at the right times.

 

You have already replaced the VSS, the next step would be to ohm out the wiring. I had some wires chewed up my some pesky squirrels on my last '93 Lightning. Amazing what those critters can do!

I have read somewhere you can use a DVM set to AC to measure the signal output. Jack up the truck, block the wheels, place the DVM on the VSS output, run the truck in Drive up to 30-35 MPH. The meter should read in the 3.0 - 3.5 volt range. If it does not then you may have a bigger issue such as a carrier bearing problem or broken teeth off the tone ring inside the rear differential.

Several here have found the RABS valve is dragging down the VSS signal, you could try disconnecting it as a test too.