MY Polar Express engine's front wheels constantly come off the track. Any ideas? 
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Is it always happening at the same spot? Had the same problem with my MTH CHRISTMAS train. The track joint was off just enough. Drove me nuts for 4 hrs. I was about to see if trains could fly
Does it rotate freely, is the spring in place, no signs of being bent Wheel spacing equal to track spacing? G
What kind of track are you using......
Do the front wheels go off track just before a curve?
What radius curves are you using?
Turn it over and look closely at the wheel bearings at the end of the axles in the pilot truck. I think you will find that one is broken and the axle end can move around. It would be broken at the top.
Lionel has these available. Not really a dealer stocked part.
happened to me and took a while before I discovered it. They snap in, so press on the bearing edge with a flat screwdriver, one on each bearing. Pushing on the axle, while tempting, may break the new bearing.
Contact Boxcar Bill, he can hook you up with the bearings. Mine fell out and he has them. They snap right in.
| 6208616051 | AXLE BEARING / PLASTIC / PILOT TRUCK |
for the Polar Express
https://ogrforum.ogaugerr.com/profile/2415514336262158
Jerry
Also note if any turnouts are involved. I had many problems with 2 wheel pilots transitioning turnouts.
Stack
Originally Posted by BFI66:
What kind of track are you using......
Do the front wheels go off track just before a curve?
What radius curves are you using?
O36 Fastrack. Usually go off at curves. I've tried hammering down those places where connection does not seem smooth. This seems to help some.
Can you clarify which PE you are using?
You can add a little stick-on wheel weight to the pilot to assist. We do that with G equipment all the time. 
Please don't hammer Fastrack. You can loosen the tabs and lower/raise the track a bit to level it out. Mashing the top just makes it deform on the sides.
Another thought: You may have WWS (Wobbly Wheel Syndrome). I've had to send two, yes TWO PEs back to lionel for wobbly wheels. You will notice the engine rock side to side on straights, and on curves it sometimes derails as the force drives it sideways.
You can also flip her over and apply power to the pickups with spare wire to rotate the wheels. If they are out of round, she needs a wheel set.
Originally Posted by Volphin:
Can you clarify which PE you are using?
You can add a little stick-on wheel weight to the pilot to assist. We do that with G equipment all the time.
Please don't hammer Fastrack. You can loosen the tabs and lower/raise the track a bit to level it out. Mashing the top just makes it deform on the sides.
Can you please what you mean by a "...add a little stick-on wheel weight to the pilot...". Not sure how to do it, not sure what to use. Thanks.
Can you post a picture of the pilot. The engine shouldn't do this, so you either have an issue with a bent axle, bent pilot frame, poor wheel spacing, or such. G
Dude, stop by your local tire store. They will toss you a few .oz for free. It is a thin strip of lead with a self adhesive back used for balancing car wheels where standard clip-on wheel weights can't be used due to the lack of a wheel flange... (the lip of the wheel).
But G is right... something is not right with that pilot axle, or your main drivers are bent. Does it waddle down the track on straight sections or roll evenly?
If its one of the new engines that have the problematic bearing caps that break and fall out, it could be that they are coming loose. When that happens, the pilot truck hits the steam chest in the curves, restricting the trucks movement. Those plastic axle bearings must be shoved all the way in... they should be deeper down than just being flush with the bottom of the truck.
Take your engine, sit it on a flat table...no track, and see if that pilot truck moves freely from side to side? Or does it hit the steam chest on either side??
Take your engine, sit it on a flat table...no track, and see if that pilot truck moves freely from side to side? Or does it hit the steam chest on either side??
I hope this'll help. I responded here on another thread:
Legacy NKP 765 parts in box. Help!
https://ogrforum.ogaugerr.com/t...68#38737270696118068
December 7, 2014 7:23 PM
--Jim
Originally Posted by GGG:
Can you post a picture of the pilot. The engine shouldn't do this, so you either have an issue with a bent axle, bent pilot frame, poor wheel spacing, or such. G
Here you go...
Attachments
Images (2)
It looks to me like the right (as shown in your pictures) bearing is missing on the pilot truck. It could be just a shadow though.
J White
I also have this problem, identified but not fixed yet: one of the wheel bearings has a casting flaw that looks like not enough plastic was injected. The missing area is part of the actual bearing surface. It's a gap big enough for the axle-end to pop out, and then pony truck derailment. I have some brass axle bearings somewhere that I'll try (when I find them )
The left rear trailing truck large wheel bearing looks suspect, although it may just be the photo.
The right side rods are bent and could be jamming. They need to straightened, but without the correct nut driver, I don't know how you can do it properly. They need to be removed. Prying them outward will only put another bend it.
Just grab the rear trailing truck axle with some needle nose pliers and gently pull towards you. It should not move at all.
The pilot truck bearings look ok, but check all of the axles with a gentle pull with the needle nose pliers.
Attached photos zoomed and annotated.
Attachments
Images (2)
Originally Posted by Firewood:
I also have this problem, identified but not fixed yet: one of the wheel bearings has a casting flaw that looks like not enough plastic was injected. The missing area is part of the actual bearing surface. It's a gap big enough for the axle-end to pop out, and then pony truck derailment. I have some brass axle bearings somewhere that I'll try (when I find them )
The bearing has a small snap tab and pushes in to the side plate. You definitely have a broken bearing. You really need the replacement part, but, your fix may work for Christmas. You can order them online at Lionel or call customer service.
Since the trail truck doesn't derail I am going to assume the bearing is just a shadow.
The front pilot does look fine, but you need to make sure it rotates freely around the mounting screw. Also there should be a spring on the rivet that it rides against. A side angle picture could also shed light on this. Is the spring in place? Does it provide firm pressure to keep the pilot down, does the pilot rotate freely around the screw? G
Originally Posted by GGG:
Since the trail truck doesn't derail I am going to assume the bearing is just a shadow.
The front pilot does look fine, but you need to make sure it rotates freely around the mounting screw. Also there should be a spring on the rivet that it rides against. A side angle picture could also shed light on this. Is the spring in place? Does it provide firm pressure to keep the pilot down, does the pilot rotate freely around the screw? G
All of that is fine. I took the truck off and added some lead strips. This is an elevated track. On some curves if i "bank" the trestle a little, it helps some.
When my PE was new back in 2005 or 2006, it had a similar problem with the front truck derailing on a curve portion of a O36 turnout. No other engines or cars had any problems--just the Polar Express front truck, and mostly on one 036 turnout. I remember "banking" the track slightly for the curve which helped a lot, but that just masked the problem.
I measured the gauge of the track on the turnout and it was dead on, but when I measured the gauge of the front truck, it was slightly off. Apparently, when going at a reasonable speed on the curve, the front truck would ride up just enough to derail and mostly on that one turnout although it rarely happened on other turnouts. I contacted Lionel while still under warranty at the time and they sent me a new front truck which I just swapped out and the problem was gone forever.
I have a PE Berkshire engine (around 2007 - 2010 year) where the front pilot and driver wheels would derail on 027 - 42" diameter curves. I then tried running it after removing the front pilot truck, but the driver wheels would still derail. The linkage and rods all operate smoothly. The trailing truck operates fine. All the track is level on a plywood table top. Still trying to figure it out
Dave
@Drummer3 posted:I have a PE Berkshire engine (around 2007 - 2010 year) where the front pilot and driver wheels would derail on 027 - 42" diameter curves. I then tried running it after removing the front pilot truck, but the driver wheels would still derail. The linkage and rods all operate smoothly. The trailing truck operates fine. All the track is level on a plywood table top. Still trying to figure it out
Dave
It may be the rail height is too low if you are using 027 track. O gauge 036 curves for the Berk as a minimum.
@Moonman posted:O gauge ... ... curves for the Berk as a minimum.
Is this stated somewhere in Lionel's documentation or on its website?
Or perhaps, is it a rule of thumb (undocumented feature - LOL)?
Mike
@Drummer3 posted:I have a PE Berkshire engine (around 2007 - 2010 year) where the front pilot and driver wheels would derail on 027 - 42" diameter curves. I then tried running it after removing the front pilot truck, but the driver wheels would still derail. The linkage and rods all operate smoothly. The trailing truck operates fine. All the track is level on a plywood table top. Still trying to figure it out
Dave
Some of those PE starter set engines from that time period I’ve noticed the driver wheels are extremely soft castings, and the flanges get ground down to the point they jump the track,…., and tube track seems to accelerate their demise. I’ve fixed oodles where they needed a front driver set. Sometimes both the front & last set of drivers……especially if all the did was circle around the Christmas tree for hours on end….post up a picture ( close up ) of the front set of drivers on your engine,….that’ll clear up the mystery…..
Pat
Put the engine upside down on a towel or soft cradle and apply power to the unit via jumper wires. Operate the engine slowly forward and reverse. Betcha the leading or trailing drivers are bent. I've fixed several (including my own) after getting tired of sending them in.
Volphin, if the drivers are bent, how did you straighten them? Also, I am using 42" diameter curve track, but they are the lighter O27 gauge, not O-gauge.
@Drummer3 posted:Volphin, if the drivers are bent, how did you straighten them? Also, I am using 42" diameter curve track, but they are the lighter O27 gauge, not O-gauge.
You don't. You replace them with a new front and/or rear wheel set from Lionel. They should have lots of them in stock.
