I now have my first P4 converted locomotive. My Bachmann 08.
I've had the Ultrascale wheels for long enough and there was nothing on the TV so, spurred on by Yans progress with his first P4 conversion with the thought that my 6 coupled 08 couldn't be any more difficult than his 6 coupled Pannier Tank. I pulled the model out of the box.
The P4 wheels are just a straight replacement for the old ones. It's as simple as that. You don't have to do any major disassembly of the chassis. Just pop out the plastic strip that holds the brake gear in place and unscrew the keeper plate that hold the wheels in place. Take the old wheels out. Put the new ones in and swap over the connecting rods. Though you do have to drill the crank pin holes out to 2.1mm to fit over the new crank pins. Not a difficult task just be careful. Pop the keeper plate back in place and the brake gear strip and put it on the track turn on the power and...
It doesn't go.
Because these wheels are narrower and further apart than the old ones the contacts on the backs of the wheels for current collection don't. Contact the wheels that is. So you have to undo everything you just did. Remove the wheels bend the contacts so that they touch the back of the wheels.
Pop it on the track. Turn the control and...
It works! it runs just as smoothly as before.
Got to admit to feeling pretty pleased with myself tonight.