A friend of mine (Pete) once suggested that I take the frame/driver/truck assembly (without the boiler) to the club tracks and make sure everything works right without binding before permanently mounting the boiler.  That way, if you need to make any changes, it would be much easier.  So...  I brought the frame assembly to the club and hitched her up to my switcher.  I pulled her around the track several times and had no problems on the mainline.  The yard was another matter as it has a very tight turn.  Not sure what the radius is but I figured that if I was going to run at this and other clubs, I wanted to make the 4-8-4 to be as flexible as possible.

We'll, MAJOR work needed to be done.  First, I disassembled nearly everything.  Off went the side rods, drivers, trucks...  I re-machined the driver journals to increase the lateral movement.  I then decided to remake all the brass bushings for the side rods as thin as possible to give the rods more room to move.  Here are the new ones I made.

The heart rockers in the front truck were rubbing on tight corners so I disassembled the front truck and did some liposuction on the heart rockers.  The rockers on top are before modifications, the ones on the bottom are after.

Now this part is where things get a bit radical.  My rear truck wheels were scraping in the frame during turns.  I had no alternative except to start cutting away.  You can see in the picture below the steel bars that were bolted on the the frame to compensate for the cutouts..  It gave me another 5/8" in each direction for the rear wheels to swing.  I know this looks like crap but after the boiler is put back on, it will hardly be notice.  I felt operation was more important than looks.

Rock and Roll...

You know the saying, fix one thing and something else breaks.  Well... the rear rockers couldn't swing as far as the truck could now move.  So, I made new ones out of brass and installed a roller bearing.  I installed a plate on the bottom of the frame which rides on top of this "rigid" rocker.  The old rocker is in the foreground.

After I made all these modifications, I took her back out to the club to see if all my work paid off.  I have to say, for a Northern, this thing takes pretty tight turns now.  I know I could have used blind drivers, but I just couldn't bring myself to cutting off those flanges.