I'm having trouble with the front guide wheels on my 2037 locomotive. I had a couple of directional switches that I swapped out because the wheels would hop off the track when they passed through the switch. Some were OK if they were on the inside loop but would mess up right away on the outside loop.
After a lot of frustration I bought a set on eBay that were nearly new and cut the derailing to about 40% of the time but it was still frustrating. I put a little stiffer spring over the top of the one on the assembly but that didn't help and sometimes caused a complete derailment. I ended up pulling them off and it runs fine except it looks funny with nothing there.
What is the remedy for this???

They measure the same. I took the wheel assembly and ran it across the switch and don't feel anything weird.

O27 #1122

Since the 1122 switches operate on track power, check to make sure the swivel rails are moving all the way over. They may be acting sluggishly due to low track voltage. Turn the lantern by hand to insure the swivel rail is fully over. If this helps, you may need higher voltage to properly throw the switches. That will involve modifying the switches to accept a constant voltage source.

What transformer are you using?

Larry

Push the locomotive over the switch by hand and observe the front truck. If it derails, exactly where on the switch does it derail?

Larry

If you are talking about it derailing on the 'X' shaped piece, you can gently pry it up and take it out. Try your locomotive without that piece and see how it works.

Larry