Lionel Legacy K4 Gear Box fix, Tales From Harmon Shops

Compiled a list of all the numbers from 2011-2020(since 2011 was the first K4 offering).

So, here is the list. There are a lot of Mike's

K4's Design Flaw Fail!
6-11264 PRR 1361 2011 fail
6-11265 PRR 1330 2011 fail
6-11266 PRR 1361 conventional 2011 fail
6-11331 Polar Railroad conventional 2011 fail

6-11327 PRR 3667 2011 fail
6-11329 PRR 3678 2011 fail
6-11319 Tuscan PRR 5409 2013 fail
6-11320 Tuscan PRR 5436 conventional 2013 fail

6-11330 PRR Polar Railroad #25 2014 fail
6-84116 PRR 5432 LHT 2016 fail
6-84115 PRR 5385 LHT 2016 fail
6-84816 PRR Broadway Limited 5493 2017 fail
1922030 PRR W.G. Harding Funeral 3750 2018 fail

Mike's
6-11278 WP 322 2011 fail
6-11279 WP 327 2011 fail
6-11280 B&O 4507 2011 fail
6-11281 B&O 451 conventional 2011 fail
6-11286 RI 2302 2011 fail
6-11287 RI 2305 conventional 2011 fail
6-11288 T&P 552 2011 fail
6-11289 T&P 557 conventional 2011 fail
6-11282 GN 3125 2011 fail
6-11284 MP 1310 2011 fail
6-11255 C&O 1062 2012 fail
6-11256 NH 3021 2012 fail
6-11257 PRR 8631 2012 fail
6-11258 Southern 4501(Green) 2012 fail
6-11259 UP 2840 2012 fail
6-11260 RG 1207 2012 fail
6-11261 DM&IR 1305 2012 fail
6-11262 Erie 3007 2012 fail
6-81182 L&N 1757 2014 fail
6-81184 P&WV 1152 2014 fail
6-81185 C of NJ 845 2014 fail
6-81186 Frisco 4126 2014 fail
6-81187 C&IM 551 2014 fail
6-81188 NYC 9506 2014 fail
6-81192 GN 3148 2014 fail
6-88179 Pilot 2014 fail
6-81183 MP 1496 2015 fail
6-81181 Southern 4866 2015 fail
6-81189 CB&Q 5509 2015 fail
6-81038 MR 8693 2015 fail
6-81191 Erie 3207 2015 fail
6-81190 WP 334 2015 fail
6-81193 W&LE 6012 2015 fail
6-81180 Black Unlettered 2015 fail
6-81194 NPR 689 2015 fail
6-84532 NPR 587 2017 fail
6-84466 GTW 3734 2017 fail
6-84467 MC 624 2017 fail
6-84468 NYC 5187 2017 fail
6-84469 PRR 9630 2017 fail
6-84470 Southern 4758 2017 fail
6-84465 B&O 4500 2017 fail
6-84471 UP 2537 2017 fail
2131310 ACL 823 2020 fail
2131330 GTW 4070 2020 fail
2131320 Georgia 300 2020 fail
2131340 L&HR 83 2020 fail
2131350 Monon 554 2020 fail
2131360 Frisco 4003 2020 fail
2131370 Southern 4501(Black) 2020 fail
2131380 Wabash 2202 2020 fail

USRA Chassis different from K4 design motor in Firebox connected to worm/gearbox with shaft
Pacific's
6-11338 Alton Limited 657 2012 Pass
6-11335 Blue Comet 832 2012 Pass
6-11334 Cresent Limited 1393 2012 Pass
6-11423 Blue Comet 833 2012 Pass
6-85170 A&WP 290 2018 Pass
6-85171 B&O 5300 2018 Pass
6-85172 R&N 425 2018 Pass
6-85173 NP 2256 2018 Pass
6-85174 Southern 1372 2018 Pass
6-85175 Halloween 1031 2018 Pass

All Pass for 2021 offerings

2122070 Asa Packer Set Lehigh Valley #2023 2021
2122080 Cardinals Set NYC #4899 2021
2122170 Santa Fe Valley Flyer #1369 2021
2131240 Atlantic Coast Line #1504 2021
2131250 GM&O #5296 2021
2131260 Great Northern #1385 2021
2131270 M-K-T #411 2021
2131280 Nickel Plate #168 2021
2131290 Southern Pacific #611 2021
2131300 Union Pacific #3218 2021
2131660 B&O #5236 MR. Muffin's Trains 2021
2131670 Delaware, Lacakawanna & Western #1133 MR. Muffin's Trains 2021
2131680 Louisville & Nashville #280 MR. Muffin's Trains 2021
2131690 Monon #444 MR. Muffin's Trains 2021
2131700 New York Central #3330 MR. Muffin's Trains 2021

H10's
6-84953 PRR Coal Hauler 1773 2018 fail
6-84948 PRR 1288 2018 fail
6-84949 PRSL 6072 2018 fail
6-84951 Bellefonte Central 2018 fail
6-85386 Pennsy Lines West 7109 2018 fail
6-84950 LI 109 2018 fail
6-84952 Weathered PRR 3529 2018 fail
6-85387 Western Allegheny 85 2018 fail

I can edit the list to take stuff off if we need to.

I can edit the list to take stuff off if we need to.

My original Post ",Wow, that looks like something I would wind up blowing up if I tried, lol. I have several of the K4 runs and haven't had them out of the box since no track big enough to run them on(unless I carpet run). I don't know if the TMCC 1361 K4 has that issue(wouldn't expect it to be, but what do I know). I guess we'll see more of these getting fixed when you are less busy with work and more engaged in "retirement", haha."

@harmonyards posted:

……I believe we’re just touching the tip of the iceberg with issues like this on Legacy gear boxes that have a similar construction and compound gear arrangements…..this fix will apply to more models than just the K4, that I’m sure of,…...

Pat

Time will tell, but as far as more models. This gearbox setup is in just about every locomotive Lionel has produced these days.

My H10 is the last locomotive I will purchase with this design. At least the bottom cover comes off so it might make repair a bit easier for you should I ever need it.

Hopefully 10 years from now we don't have locomotives piling up with faulty gearboxes.

For whom it may concern. Lionel makes no mention of the need to lube these extra shaft bushings in the chassis. It's a good idea to shine a flashlight through the spokes of the drivers and find these to give them a couple drops of light oil.

The Legacy K4 is a different design than the TMCC version, so I would be surprised if it has the same issue.

@Dave NYC Hudson PRR K4 posted:

I don't know if the TMCC 1361 K4 has that issue(wouldn't expect it to be, but what do I know). .

This gearbox is strictly a Legacy design and appeared in 2011 in these first run k4s.

From there ,it found its way into the light and heavy mike's, northerns, mountains, consolidations,pacifics articulateds etc.

Its not used in the ESE hudsons or the j3a . It is not in the small 0-6-0s either.

The K4 chassis I sent to Pat was the Legacy K4, so we know it has the problem.  I just don't know if I should take my working K4 apart and do this fix to it as well! 

@gunrunnerjohn posted:

The K4 chassis I sent to Pat was the Legacy K4, so we know it has the problem.  I just don't know if I should take my working K4 apart and do this fix to it as well! 

I have two that I run double headed, and I hope that helps reduce the strain on them so they last longer.  At least there is a fix.  Thanks Pat!

@Dave NYC Hudson PRR K4 posted:

Wow, that looks like something I would wind up blowing up if I tried, lol. I have several of the K4 runs and haven't had them out of the box since no track big enough to run them on(unless I carpet run). I don't know if the TMCC 1361 K4 has that issue(wouldn't expect it to be, but what do I know). I guess we'll see more of these getting fixed when you are less busy with work and more engaged in "retirement", haha.

I think it only affects K4s from the newer K-Line tooling. P.S.  I think most K4s with the short tender can negotiate O36 just fine.

@RickO posted:

This gearbox is strictly a Legacy design and appeared in 2011 in these first run k4s.

From there ,it found its way into the light and heavy mike's, northerns, mountains, consolidations,pacifics articulateds etc.

Its not used in the ESE hudsons or the j3a . It is not in the small 0-6-0s either.

It’s also in the small  Legacy Berks, and the legacy Mohawks if I’m not mistaken Rick, …..I know the legacy small Berks use this design, and I have a brand new chassis I’m swapping into a KLine B&M Berk, that will get the mod as a preemptive strike…..it’s just cheap insurance if it’s new,….there’s no telling with out time, like you’ve mentioned, if it’s a chronic failure, or just certain ones are proved to fail,….

Pat

@rplst8 posted:

I think it only affects K4s from the newer K-Line tooling. P.S.  I think most K4s with the short tender can negotiate O36 just fine.

Wrong, some of the H10’s as Rick has mentioned have the same issue…..

Pat

Since this is a design introduced with Legacy engines, I have not read/heard of any other legacy engines having this problem.  Could it be that only the K4s had an issue with too much slop in the gears?  I would think if the slop issue was that bad and prolific , there would be reports of problems with other locs.  It would be great if Lionel could confirm they fixed the slop issue.  Simple spacers in the gear box could solve this issue during manufacturing. @Dave Olson

@CAPPilot posted:

I have two that I run double headed, and I hope that helps reduce the strain on them so they last longer.  At least there is a fix.  Thanks Pat!

I can’t see double heading them preventing a failure…..the condition exists due to the way the bushing on the back side of the worm wheel rides up against the intermediate shaft bushing that is pressed into the gear box casting ( ie; the frame) …..the worm wheel’s bushing is being ground against that shaft bushing, ……both are so tiny, they can’t help but to wear one another out, and then the gear and the shaft walk to one side, and thus resulting in the worm wheel and the worm gear not making solid contact, but rather just on the edge, …..then it’s curtains….if the damage isn’t severe, the fix will restore it, but if the damage to the worm wheel is severe, then the chassis is scrap,…….for comparison, I looked at MTH’s compound gear box design used in Premier articulates, ….it’s nothing like the Lionel version,…..way more robust, with giant bushings to keep the idler centered,…..

Pat

@Joe Fermani posted:

Since this is a design introduced with Legacy engines, I have not read/heard of any other legacy engines having this problem.  Could it be that only the K4s had an issue with too much slop in the gears?  I would think if the slop issue was that bad and prolific , there would be reports of problems with other locs.  It would be great if Lionel could confirm they fixed the slop issue.  Simple spacers in the gear box could solve this issue during manufacturing. @Dave Olson

It may very well be only this particular model exhibits the issues in more than low numbers, ……I believe John has fixed a few with new chassis, but only time will tell if they fail,….as far as other models, I believe Rick O has shown us his H10 with gear box issues……we do not know if this is going to be a chronic issue or not,….

Pat

@harmonyards posted:

……the Lionel Legacy K4 has an issue with the gear box going into self destruct mode…..the compound gear box has an idler gear arrangement that walks away from the worm gear on the motor…

Why, why, why, would they do this?!

A 30c bushing could have prevented all of this.

Or a 10c c-clip on the side of the intermediate shaft that has the small output gear. 

My physics is escaping me at the moment, but if I remember the right hand rule correctly all they had to do was put the output gear on the other side and shift everything right.  Then the torque force would have kept the intermediate gear against the final gear when running forward.

I wonder if this is why the KLine models had the motor output shaft rear facing.

@harmonyards posted:

Wrong, some of the H10’s as Rick has mentioned have the same issue…..

Sorry I should have been more specific.  I meant of all the K4s out there.

@rplst8 posted:

I wonder if this is why the KLine models had the motor output shaft rear facing.

The Legacy K4 has the motor shaft rear facing, that's why it's a problem!   It looks just like the K-Line when you take them apart.

Most steamers have the shaft facing forward, don't know why they did this, it appears they copied the K-line chassis.

@harmonyards posted:

It’s a known issue; ……the Lionel Legacy K4 has an issue with the gear box going into self destruct mode…..the compound gear box has an idler gear arrangement that walks away from the worm gear on the motor……I’ve developed a fairly simple solution that’s non-invasive, and will have good longevity. The new fix requires no wheel pulling, no gear pressing, no harm to the chassis, …..one small hole must be drilled into the side of the gear tower,……the fix is a brass flat bar stock, with a U shaped bushing to cut down on parasitic drag of the flat bar up against the gear it’s guiding towards center……I believe we’re just touching the tip of the iceberg with issues like this on Legacy gear boxes that have a similar construction and compound gear arrangements…..this fix will apply to more models than just the K4, that I’m sure of,…..thanks to David Ross, for sending his K4 that had completely lost gear engagement and is now out of field testing and doing fine. Also, thanks to  John Will sent a test sample that allowed me to have more than one chassis with the same problem….The fix can only be applied to those locomotives that have not totally destroyed the top worm wheel, or totally wallered out the intermediate shaft beyond repair ….it can however, be a preemptive first strike package, in other words, new or lightly used engines will benefit from the fix, as this part will keep the gear centered. Testing shows zero additional wear using Mobil 1 synthetic grease in the gear box…test was conducted 16 hours, two straight 8 hour runs, back to back,…as of this printing, I do not have an infield solution, as the parts will have to be custom made for each application, and the measured offset is different between examples, so as of this moment, chassis will have to come to my shop for fitment ……I think I covered everything I can think of, and I’m sure we’ll discuss this more on this thread,….

Pat

Funny I did the same thing with brass washers with a slot/flat cut into them. The flat spot stops them from trying to spin and they can float allowing for some movement.

@gunrunnerjohn posted:

The Legacy K4 has the motor shaft rear facing, that's why it's a problem!   It looks just like the K-Line when you take them apart.

Most steamers have the shaft facing forward, don't know why they did this, it appears they copied the K-line chassis.

Ohhh.  So did the KLine models have this issue?

@rplst8 posted:

Ohhh.  So did the KLine models have this issue?

Not that I know of.  Don't know for sure what was different, I haven't been inside the K-Line K4 for a few years.

@rplst8 posted:

Ohhh.  So did the KLine models have this issue?

I wonder if K-Line had the motor spinning the other way and thus forcing the gear over where it couldn't go far?