@rplst8 posted:Isn't the real problem that they didn't cut the worm correctly?
The "shim fix" is just trying to use the threads that are cut toward the front that are cut all the way.
I'm wondering if the ones that "work" have the threads cut all the way.
Twist my arm either way, ….either they cut it too short, or it’s pressed on the motor not enough ….pick your poison, ….
BTW, …thanks for helping Mike with the K4 pics!!…..I told him what a jerk you are!!……..NO, that’s a joke man!!!
Pat
@Paul Kallus posted:I appreciate you guys sharing the fixes, however I am not ashamed to admit, well, slightly embarrassed, that what you're discussing appears beyond than my admittingly average to below average skill set, given some health conditions that I don't want to get into. What are the remedies for blokes like me? Up a creek without a paddle? I will suggest the fix would make a great magazine article, though you guys seem very busy, and writing articles takes a good deal of time. Good thing we have a forum.
Paul, I’m another bloke like you! 😄 I could probably do the washer fix without messing it up too much!
However, I didn’t buy an affected engine. I’m not sure why I started following, but the ride has been quite educational! 🧐
@harmonyards posted:Twist my arm either way, ….either they cut it too short, or it’s pressed on the motor not enough ….pick your poison, ….
BTW, …thanks for helping Mike with the K4 pics!!…..I told him what a jerk you are!!……..NO, that’s a joke man!!!
Guilty.
With a mismatch of 0.3mm, could the problem be due to variations in how far the worm was pressed onto the motor shaft? Or perhaps, the raw chassis casting was smoothed excessively before it was painted? Or, the engineers overestimated the thickness of the paint!? My kingdom for a real gearbox!!
@Mark Boyce posted:Paul, I’m another bloke like you! 😄 I could probably do the washer fix without messing it up too much!
However, I didn’t buy an affected engine. I’m not sure why I started following, but the ride has been quite educational! 🧐
Mark, I am leaning the same way...while this engine is a must have for PRR fans, it seems a guy would be getting in over his head, at least for me, for a $800 - $900 model. Factor in that John's engine was back at Lionel and they didn't know what was wrong. I just hope the I1 doesn't have this shortcoming.
@rplst8 posted:Isn't the real problem that they didn't cut the worm correctly?
The "shim fix" is just trying to use the threads that are cut toward the front that are cut all the way.
I'm wondering if the ones that "work" have the threads cut all the way.
It would be interesting to compare a working and non-working sample. 
@Paul Kallus posted:Mark, I am leaning the same way...while this engine is a must have for PRR fans, it seems a guy would be getting in over his head, at least for me, for a $800 - $900 model. Factor in that John's engine was back at Lionel and they didn't know what was wrong. I just hope the I1 doesn't have this shortcoming.
Paul, I agree. I’m okay with taking apart an old engine, but not a new one and risk breaking something. I could void a warranty. Yes, hopefully the I1 doesn’t have the same problem!!!!
Knock on wood, my son appears to have ended up with one that works as advertised. Only issue was the lack of grease. It’s actually one of the smoother engines I’ve tried. Hopefully I didn’t jinx it by posting this, but I think it’s good to let people know they don’t all appear to be defective.
I really considered purchasing a L1. But the gearbox issue and the color issue convinced be buy a used engine instead. It was considerably cheeper and I will not feel bad if I have to open it up for repairs or send it off to be fixed. BTW after clearing up some minor shipping problems with the drawbar, pilot and headlight the engine runs great. If this was brand new I would be really upset with these issues on a brand new engine.
@Ted S posted:With a mismatch of 0.3mm, could the problem be due to variations in how far the worm was pressed onto the motor shaft? Or perhaps, the raw chassis casting was smoothed excessively before it was painted? Or, the engineers overestimated the thickness of the paint!? My kingdom for a real gearbox!!
My feeling is that the worms have to be installed onto the shaft with the same clearance within a pretty tight tolerance or the threads need to extend a bit further. Comparing this worm to some K-Line stuff laying around in my shop, these are a bit shorter than the old K-Line 2-start worms. These motors have very little ability to take up any thrust so the centering of the worm gear and wheel is critical. Still gotta wonder how these are assembled and tested. Seems like they would want to have these assembled without shimming each one individually. Wonder why other examples of this style gearbox don't exhibit this issue. 
At one point I considered milling a wide slot lengthwise down the cover to get a visual on the gears.
@Norm Charbonneau posted:My feeling is that the worms have to be installed onto the shaft with the same clearance within a pretty tight tolerance or the threads need to extend a bit further. Comparing this worm to some K-Line stuff laying around in my shop, these are a bit shorter than the old K-Line 2-start worms. These motors have very little ability to take up any thrust so the centering of the worm gear and wheel is critical. Still gotta wonder how these are assembled and tested. Seems like they would want to have these assembled without shimming each one individually. Wonder why other examples of this style gearbox don't exhibit this issue.
At one point I considered milling a wide slot lengthwise down the cover to get a visual on the gears.
I can't understand what would be the purpose of making the installation so critical, that seems like you're just asking for these kinds of problems! Why wouldn't you just cut the worm threads long enough to allow for some tolerance in assembly and remove any possibility of this happening? What did they really save by making the worm "just long enough"?
I just wonder how all the other ones like this didn't seem to suffer this lockup issue. The multi-start worm is kind of interesting though and probably helps to keep this drive loose/more compliant in back-drive scenarios.
@gunrunnerjohn posted:I can't understand what would be the purpose of making the installation so critical, that seems like you're just asking for these kinds of problems! Why wouldn't you just cut the worm threads long enough to allow for some tolerance in assembly and remove any possibility of this happening? What did they really save by making the worm "just long enough"?
More than likely, they used existing components in their arsenal, which saves them money in manufacturing. Combine that with a retooled chassis, and stuff just didn’t jive …..so the gear on the motor probably already existed, as well as the gears in the well, and they crafted, or attempted to craft the new gear box around those parts,…..and obviously they failed,…..as far as why aren’t more falling out, the inconsistencies in casting the drive block ( shrinkage, etc, ) more than likely plays a role in which ones fail, and which ones survive, ……
Pat
@harmonyards posted:More than likely, they used existing components in their arsenal, which saves them money in manufacturing. Combine that with a retooled chassis, and stuff just didn’t jive …..so the gear on the motor probably already existed, as well as the gears in the well, and they crafted, or attempted to craft the new gear box around those parts,…..and obviously they failed,….
Pat
I thought this was the same K Line chassis used in every other problematic loco, modified to accept the MTH L1 shell.
@RickO posted:I thought this was the same K Line chassis used in every other problematic loco, modified to accept the MTH L1 shell.
Nope, ….there’s clear evidence they worked the MTH chassis Rick. I pointed that out early in this thread. The grounding towers for MTH’s 3/2 rail option is still there, casted in the frame.
Pat
I stand corrected Pat. Oh wait, they used the MTH chassis?
That's a good thing,......oops, nevermind lol!
Pete, Lou & myself discussed this engine when I first opened up Dave’s and I could not for the life of me understand why they went the route they did. I wondered why they didn’t leave the bullet proof MTH chassis alone, and redesign the electronics around it, but I guess that big board needs a fair amount of real estate, so they did what they did for that purpose, ….had they left the MTH chassis alone, the board as it sits would have to live in the tender, ……
Pat
I think if Lionel did the Canon drive in this, the price would have been too high for being a less than perfect model with that mismatched tender. Also having a tether and crowding out the nice sound setup they have in the tender would not have made any sense at all.
BTW, now that I can finally start to enjoy these engines I do have to say the sounds are really good. There seems to be a new chip set on the sound board.
Pat and others, could it be that MTH merely sold or leased the shells and not the chassis design? I don't mean to steer off topic but isn't that what the legal issue was all about, or in layman's terms, the chassis = sub-assembly is "where the money = engineering is." If so, MTH was very smart as they kept the rights to make all these models using their sub-assemblies in the future.
As for some people not experiencing the gear lockup, could it be as simple as they're not running the engines under the same load in reverse? I admit when I test run an engine that is new, I only test it forward and backward, and not under load. This topic has taught me a lesson, or two!
@Norm Charbonneau posted:I think if Lionel did the Canon drive in this, the price would have been too high for being a less than perfect model with that mismatched tender.
The Lionel L1s with the non-doghouse tender aren't mis-matched.
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