My K4 Pacific is slipping under load. Any suggestions? Is there any easily accessible screw that holds the motor in place that perhaps has come loose? I'm not too keen on pulling it open unless there is a reasonable probability there is a simple fix that I am qualified to handle.
David
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Could you explain "slipping"? Are the wheels slipping on the track? Is the motor skipping gears under load?
If you run it that way, there is an excellent chance of stripping one of the gears, usually the hardest one to replace.
What is the catalog number? That will allow everyone to look at the parts diagram on the Lionel website.
Unfortunately, the Legacy K4's apparently have a weak gearbox design. Lots of information (none of it good for you) is in this thread:
@RoyBoy posted:Could you explain "slipping"? Are the wheels slipping on the track? Is the motor skipping gears under load?
If you run it that way, there is an excellent chance of stripping one of the gears, usually the hardest one to replace.
What is the catalog number? That will allow everyone to look at the parts diagram on the Lionel website.
Motor is slipping, not the wheels. You can hear the sound.
Adding to what Bob said. I was one of, if not the first to recognize this gearbox design as a problem.
Theres an intermediate gear that rides on a shaft that spins inside bushings pressed into the chassis.
If you turn the wheel so the spokes are facing upward, so you can see behind the wheel you will see this shaft in the bushing.
With the loco powered down rock it back and forth. You"ll likely see excessive play, shavings and an oblong bushing that allows the shaft to rock back and forth. Once this slop gets too bad the gears no longer engage.
The only way to repair this is to replace the entire chassis.
Gunrunnerjohn has seen/repaired several of these failures.
Worst part is, Lionel is currently putting this gearbox in just about everything.
@RickO posted:The only way to repair this is to replace the entire chassis.
Replace the entire chassis? Oh My Gosh! NH Joe
Does the vision line Hudson have this gear box? I thought I heard something similar with mine.
This is a classic failure, I've fixed a bunch of these. Unfortunately, the "fix" has been to replace the entire drive block! If one were to have the inclination, you could pull all the wheels and potentially fix the gear, but that requires a lot of work and quartering all the wheel sets again. It's plenty of work to install the new driveblock and move all the electronics and hardware from the old to the new.
With that scare out of the way, it is possible for the motor mount to come loose, that would be easy to fix. Sadly, my experience has been the issue is usually the internal gear.
John:
In your experience, does the fix keep the failure from repeating? If you don't mind, you can email me an estimate of that service. Looks like I will continue to do my part to keep you busy with Lionel failures.
The fix is not cheap David, it's a fair amount of labor to take the engine apart down to the frame and then build it back up again. Add to that the cost of the drive block, and you're looking a spending significant money.
That is unfortunate. It is a Harry Heike weathered piece.
Any video of the failure mode? I have two of these. Maybe it's time to peek at the gearboxes.
@RickO posted:Worst part is, Lionel is currently putting this gearbox in just about everything.
Yikes...why? 
Mark in Oregon
Is this issue exclusive to the Legacy K4s from 2017 or are the ones from 2010-2011ish safe? Also, Rick O you said they're putting it in just about everything...I'm no expert by any means, but does that include engines smaller or larger than a K4/J1 Hudson type? I would assume if it's a chassis issue then the smaller engines or larger might not have the same problem. Thanks!
@A.J. posted:Is this issue exclusive to the Legacy K4s from 2017 or are the ones from 2010-2011ish safe? Also, Rick O you said they're putting it in just about everything...I'm no expert by any means, but does that include engines smaller or larger than a K4/J1 Hudson type? I would assume if it's a chassis issue then the smaller engines or larger might not have the same problem. Thanks!
Going by what’s already been thrown out by more experienced modelers, this thing has been around since the 2011 run of the K4’s, and has been in almost everything of equivalent or larger size locomotives.
The Vision Hudson and the first run of the Berkshires didn’t have this (thank god), and I haven’t gotten indication if really small engines like the B6 or A5 have thus yet, but so far the K4’s are the most notable for this fatal flaw, at least here on the forum. I haven’t seen any other locomotives with this breakdown being fully discussed, at least not yet...
@A.J. posted:Is this issue exclusive to the Legacy K4s from 2017 or are the ones from 2010-2011ish safe? Also, Rick O you said they're putting it in just about everything...I'm no expert by any means, but does that include engines smaller or larger than a K4/J1 Hudson type? I would assume if it's a chassis issue then the smaller engines or larger might not have the same problem. Thanks!
Several of the K4's I've replaced the drive block on have been the 2011 version, so the answer is no.
Well, I've got two of the 2011 versions that I doublehead. Can I prepay for the drive blocks now
@Mikado 4501 posted:Going by what’s already been thrown out by more experienced modelers, this thing has been around since the 2011 run of the K4’s, and has been in almost everything of equivalent or larger size locomotives.
The Vision Hudson and the first run of the Berkshires didn’t have this (thank god), and I haven’t gotten indication if really small engines like the B6 or A5 have thus yet, but so far the K4’s are the most notable for this fatal flaw, at least here on the forum. I haven’t seen any other locomotives with this breakdown being fully discussed, at least not yet...
Not to stray off course, but for the record,....the legacy ESE, and the latest J3a offering are worm on single worm wheel ( what we’d like to see) ....the chassis differs from VL, to ESE and the latest J3 offering,......I can not speak of the VL Hudson as I don’t own one....( yet) .....all 3 chassis from what I can see, are altered Kline chassis, ....the VL, I’m going off pictures,.....the latest J3 and the ESE I have here in the shop, ....although the two chassis are very similar in some basic aspects to the Kline, they’re are distinctive differences even between the two,....notably the gear box design ( obviously since Lionel changed the way the motor faces) .....I took both the ESE and the latest J3 apart for observation,.....the ESE’s gear box is slightly different from the J3’s ,....however, again looking at pics of the VL Hudson, that gearbox design looks like the later J3’s .....so clearly they’ve been tweaking the redesign Kline chassis as they go along, .....probably ( my guess) to keep up with electronics or further cut costs,....
as far as the Legacy K4’s, somebody send me a dead chassis that doesn’t have the gears all ate up, and I’ll see about engineering a fix,....this will require pulling drivers, ....I see that coming, but I have the proper fixtures to do this right,.....😉
Pat
@harmonyards posted:Not to stray off course, but for the record,....the legacy ESE, and the latest J3a offering are worm on single worm wheel ( what we’d like to see) ....the chassis differs from VL, to ESE and the latest J3 offering,......I can not speak of the VL Hudson as I don’t own one....( yet) .....all 3 chassis from what I can see, are altered Kline chassis, ....the VL, I’m going off pictures,.....the latest J3 and the ESE I have here in the shop, ....although the two chassis are very similar in some basic aspects to the Kline
Pat
But, K Line didn't use the complex gearbox design correct Pat?
And why is it the Hudsons don't use/need this complex gearbox?
Lastly, why this gearbox migrating into everything? Is it compensating for something lacking in the capabilities of the Canon motor Lionel is using?
Lou had mentioned the backdriveability. The early legacy gearboxes with the simple worm and axle gear have backdriveability, so whats the point? ( I'll take video of myself pushing my powered down 2008 Legacy M1b around the layout if you don't believe me
)
Just for the sake of discussion here Pat, I welcome Lou's 2 cents as well.
Any way you slice it. More moving parts always has the potential for more problems. Of course, I'm not telling you anything you don't already know.
I still find it ironic that M.R. R.T and J.Z. got the heck out of dodge. Whatever the circumstances were before the stuff REALLY started hitting the fan. Defects, failures, and incorrect paint, seem to be at an all time high.
@RickO posted:But, K Line didn't use the complex gearbox design correct Pat?
And why is it the Hudsons don't use/need this complex gearbox?
Lastly, why this gearbox migrating into everything? Is it compensating for something lacking in the capabilities of the Canon motor Lionel is using?
Lou had mentioned the backdriveability. The early legacy gearboxes with the simple worm and axle gear have backdriveability, so whats the point? ( I'll take video of myself pushing my powered down 2008 Legacy M1b around the layout if you don't believe me
Just for the sake of discussion here Pat, I welcome Lou's 2 cents as well.
Any way you slice it. More moving parts always has the potential for more problems. Of course, I'm not telling you anything you don't already know.
I still find it ironic that M.R. R.T and J.Z. got the heck out of dodge. Whatever the circumstances were before the stuff REALLY started hitting the fan. Defects, failures, and incorrect paint, seem to be at an all time high.
1 No, Kline Hudson’s have the sorry forward facing Mubachi 385.....
2. I can’t answer that solidly, I’m not sure if back drive was a desire or a result in engineering. I’d surmise back drive definitely would help a motor in the lower rpm range,....but that’s nothing I can prove,....I wish my ESE hadn’t pooped the Cannon out the gate for me, ....that’d been a nice comparison, since now my ESE sports a Pittman,....it’s really smooth with the Pittman, but I have no base line to compare it too,...
3. I’m on the same wavelength as you are on this, ....seems that compound gearboxes have worked their way into the product line coinciding with Pittman’s exit, and Cannon’s entry,....( for the most part?) ....one could conclude the Cannon either has a shortcoming, or the legacy electronics have an easier time telling the Cannon how to behave,....
only thing I can add is maybe, and only a maybe if driver diameter plays a roll in whether or not a specific chassis needs the compound gear box,.....
Pat
I've done some searching about this multi-gear setup Lionel has been using and I can't find mentions of failure really besides in the K4 chassis. So I've got a couple theories:
1. The gearbox in the K4 is under some unique stress because of how it's setup causing the intermediate gear bushings to fail due to thrust loads.
2. The bushings were made of inferior material causing them to wear at an excessive rate.
3. Lionel redesigned/changed the specifications on the gearbox after the K4.
Since Lionel has been using this gearbox in multiple applications after the K4 (close to 10 years) I would think there would be more failures. I'd honestly like to get a K4 chassis in front of me to compare to a later chassis with the same gearbox to compare. I'll be bringing home a Legacy ATSF 3751 class Northern from the 2019 run in a week or two (which has this gearbox) and I'd be interested to see how it compares to the K4 gearbox.
As to why Lionel is using this gearbox I can't say. Use can't just be tied to the Canon motor. It's been used in the K-Line derrived Mikado and NYC 4-6-0T, which still have the RS385 motor in the smokebox. My bet is that it has something to do with smoothing out low speed performance with Legacy.
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