I bought a used BLI 4-8-4 J Class with sound a few weeks ago and recently noticed that it didn't sit straight on the track. After following it around the layout I noticed that the cab projects out from the tender either to the left or right, depending on which direction the curve is that it just exited from. The cab remains 'cocked' out on the straight runs and when coming out of the next curve it does the same thing following the outside of the curve, whichever direction that is. I can twist the loco side to side quite a lot but don't see what is causing it to have so much play. I can straighten it out on a straight section of track but once it goes through a curve, it stays 'cocked' to the outside of which ever direction the curve is. Any ideas or suggestions as to what to look for?
-Bob
Life is what happens while you are making other plans!
Get an NMRA gauge and check all the drive wheels to see if some are out of gauge.
Maybe that's why it was for sale.
I checked the drivers and pilot/trail wheels and all are in gauge. I just checked the side play on the drivers and the rear driver has .086" of side play; the other three drivers are all around .034" to .050". I don't know what is normal, but it looks like the rear driver needs a shim to limit the side play? Just don't understand why there is so much play in the rear one. The drivers don't show any wear on the treads.
Did you check the drawbar to see if it is binding up??
charlie
BOB,
Read the reply's from this site, about your Loco and what some did:
http://www.modelrailroadforums.com/forum/showthread.php?32693-MTH-or-BLI-N-amp-W-J-class
Frank
[quote user="zstripe"]
If your "J" has one of those "different" draw bars, your drivers are NOT the problem! Your loco is experiencing "crabbing" caused by the "self-extending" draw bar not returning to center when leaving a turn. There is a little cover on the loco covering this device (two screws, if I remember correctly). There's a teeny little coil spring under there, it needs to be TIGHTER. This can be done by either shortening the existing spring, or finding a stronger spring, from who-knows-where. You will notice that spring is what pulls the draw bar straight. The weight of the cars is what's not letting it work. OR the spring is broken, or MISSING! Be carefull not to cut off too much, or the spring will get SPRUNG! PS: I remember on the first one I did (I've done three, and they all worked perfectly afterwards) I drilled a small hole FARTHER FORWARD, and inserted a small screw, in order to stretch the sping more for more tension. That's another way of doing it. When done correctly, the draw bar should "snap" forcefully back to center, when pivoted to either side. There's like a "notch" in the bar itself that keeps it straight on straight track, once the spring pulls it there. You'll understand when you see it. Quite a ingenious design, actually. Keeps the tender close to the engine, as it should be. UNLIKE the MTH version, with a 20-foot gap there!
Mike C.
Oh, and it's a good idea to add some weight to the tender!
wobblinwheel If your "J" has one of those "different" draw bars, your drivers are NOT the problem! Your loco is experiencing "crabbing" caused by the "self-extending" draw bar not returning to center when leaving a turn. There is a little cover on the loco covering this device (two screws, if I remember correctly). There's a teeny little coil spring under there, it needs to be TIGHTER. This can be done by either shortening the existing spring, or finding a stronger spring, from who-knows-where. You will notice that spring is what pulls the draw bar straight. The weight of the cars is what's not letting it work. OR the spring is broken, or MISSING! Be carefull not to cut off too much, or the spring will get SPRUNG! PS: I remember on the first one I did (I've done three, and they all worked perfectly afterwards) I drilled a small hole FARTHER FORWARD, and inserted a small screw, in order to stretch the sping more for more tension. That's another way of doing it. When done correctly, the draw bar should "snap" forcefully back to center, when pivoted to either side. There's like a "notch" in the bar itself that keeps it straight on straight track, once the spring pulls it there. You'll understand when you see it. Quite a ingenious design, actually. Keeps the tender close to the engine, as it should be. UNLIKE the MTH version, with a 20-foot gap there!
wobblinwheel,
You were right! I took the two screws out and removed the cover and the spring was not connected to the chassis pin! Also, the wire harness was misplaced between the cab backplate and the cab, causing the cable to pull on the tender. I replaced all the parts in correct order and location and now the engine runs straight even with 5/6 passenger cars pulling on it. Also noticed the cab floor hinged plate wasn't setting down on the tender so I got it to work properly too. Guess I should have spent more time investigating the issues to see what else might be wrong. Thanks for the great comments and fine detail in the fix. As always, this is the best place to find answers to ANY problem in model railroading.
-*Bob
Always glad to help! You know now, if it ever happens again, what to do. Sometimes, more cars MIGHT make it try to "crab" again (maybe not). Just cut a loop or two out of that little spring and re-attach. You'll be "good-to-go"!
wobblinwheel Always glad to help! You know now, if it ever happens again, what to do. Sometimes, more cars MIGHT make it try to "crab" again (maybe not). Just cut a loop or two out of that little spring and re-attach. You'll be "good-to-go"!
BLI was in a hurry to manufacture and ship my N&W J that I bought about 7 years ago. I sent it back twice because the motor was popping out of it's mounts when going around a corner or under strain like pushing cars. It looks great but mechanically didn't work well. It's better now, after complaining numerous times.
Modeling the N&W freelanced at the height of their steam era in HO.
Daniel G.
The Bachmann Spectrum J's had this problem as well. The "slop" built into the loco to allow for use on tighter radii curves was the cause of this. With the Bachmann, it was an easy fix. Simply take 4 grey and 4 red KD washers, cut thru the washers on one side and then slip one color of each onto both sides of the front and rear drivers, between the frame and the drivers. No need to do the middle 2.
One of our club members has one and he uses it to pull a brass 12 car Powhattan Arrow. We did this to his and what a difference. Where it use to come out of a curve, as my Dad would say, "cattywhompus", it now came out straight everytime. Pulls the train with no problem at all, and the "crabbing" is completely gone.
Carey
Keep it between the Rails
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cjcrescent The Bachmann Spectrum J's had this problem as well. The "slop" built into the loco to allow for use on tighter radii curves was the cause of this. With the Bachmann, it was an easy fix. Simply take 4 grey and 4 red KD washers, cut thru the washers on one side and then slip one color of each onto both sides of the front and rear drivers, between the frame and the drivers. No need to do the middle 2. One of our club members has one and he uses it to pull a brass 12 car Powhattan Arrow. We did this to his and what a difference. Where it use to come out of a curve, as my Dad would say, "cattywhompus", it now came out straight everytime. Pulls the train with no problem at all, and the "crabbing" is completely gone.
I had the same issue as Bob with my BLI Class J #600 when coming out of curves. I just finished correcting it, using cjcrescent's fix of using the split washers over the axle between the drivers and the frame. I only tried the rear drivers first, and it seemed to have worked fine. I also added a puff of Kadee Grease 'em to the drawbar pivot to make it swivel more freely. Anyway, problem solved and the engine runs straight and true. But boy was it a trick getting the second pair of washers on the axle! Not much slack left to work with after getting the first pair on the other side! Whew!
I'm afraid shimming the axles might appear to cure some symptoms, but not cure the problem. The problem, as I said earlier is the "self-centering drawbar". Without proper tension on it's spring, the drawbar cannot "self-center" especially when pulling a load. Removing all the side-to-side play in your drivers will almost surely cause you troubles down the road. The drivers on a 4-8-4 need to shift latterally in order to negotiate many switches, crossovers, and tight curves. As long as the tender drawbar centers itself, so will the loco, regardless of the axle play! Do yourself a favor: fix the REAL problem!