Lionel Legacy K4 Gear Box fix, Tales From Harmon Shops

@Dave_C posted:

Going back to Pat’s very first post. The piece you show sitting on the Snap On box looks very robust and well machined when you study it close. In the picture of the install with it in place. It looks to be 2 pieces of brass stock. Do you start with a standard set piece and then shim it on a case to case basis

I thought that was the case too - but I think that's just the reflection of the brass bar off of the inner part of the gear box.  There is only one brass bar if you study closely.

@harmonyards posted:

Correct, it is indeed 2 separate pieces at first, the arm is simple brass flat stock, the spacer is machined by yours truly, to a standard size, it’s then press fitted into the arm, then brazed ( brass weld) so it can’t ever come apart,…

Dave, the "two pieces" are 1) flat stock and 2) the "bushing/spacer" that is fitted to the flat brass stock.

@harmonyards posted:

..then I sneak up on the bushing width trimming it on the mill for a precise ride……the arms I can crank out as ready to go units, then basically trim to fit,…..as mentioned, I’ve not seen a one size fit all solution in the 4 examples I’ve repaired so far,…..all 4 repairs were successful…..

I think this is why GRJ is suggesting the split brass rod.  It takes at least one of the variables out of the equation the length of flat stock and where to screw it in.  Additionally it shouldn't require modification.

@gunrunnerjohn posted:

Why couldn't we use a split brass rod with the proper diameter and drop it over the shaft and then squeeze it together so it can't come off the shaft.  We just trying to keep the gear from being able to walk over on the shaft, and I can't see why this wouldn't do the job.

The challenge here - and maybe it's not much of one - is that once you squeeze it together, I think a "set screw" of sorts to cinch it together would be a good idea.  Ideally it would clamp to the shaft, and rotate with it.  It then would ride against inner gearbox wall.  Obviously, that will create some friction, but it will be spread over a larger area and only have as much load on it as is caused by the throw out of the worm gear driving the worm wheel.  No actual load per se.

The whole reason this failure occurred is because the existing spacer drilled it's way into the shaft bushing.  This would eliminate the spacer's "drilling" since it would spin with it and the shaft, and since the new spacer would be larger than the bearing, it couldn't drill into that.

I like this idea GRJ.  The only question is... how to balance the new spacer so that it doesn't put too much of a rotational load on the shaft.  I'm not sure what sort of RPMs were talking here.

@rplst8 posted:

I like this idea GRJ.  The only question is... how to balance the new spacer so that it doesn't put too much of a rotational load on the shaft.  I'm not sure what sort of RPMs were talking here.

I think that's a non-issue.  That gear won't be turning fast enough to have any measurable effect.  Also, the brass tubing is on the shaft where the centrifugal force would be the least.

@harmonyards posted:

No, I have not had a H10 in house yet, however, I’m sure my process and parts will be identical,….as John noted, the H10 box is a bit more narrow, but still we’re seeing evidence of the “ shift” on here, and in pictures sent to me off line …..it won’t be long before one comes across my plate…..

Pat

Hmm....... I guess we will have to wait and see then(when you get one I mean).

Dave NYC Hudson and/or harmonyards - Has there been any clarification yet on the status (ie. Pass or Fail) of the 2012 Pacifics which appear on Dave’s list of models shown on page 2 of this Thread?

@PH1975 posted:

Dave NYC Hudson and/or harmonyards - Has there been any clarification yet on the status (ie. Pass or Fail) of the 2012 Pacifics which appear on Dave’s list of models shown on page 2 of this Thread?

IDK, that is the short list with the Blue Comet and other engines similar. These are definitely different from the K4's by the shells, but got me on the insides. I don't have any of the older ones, and guessing that the newest release of Pacific's would be the same as those older ones. I think someone did have the newest release from the batch that just came out, 2021 that Mr. Muffin's ran some custom runs. I think the one talked about here is on page 4 or 5.

@harmonyards Pat, do you think that those Pacific's are not the same design as the K4'S and probably okay or would there be some research needed there? Also, would these be the same as the most recent release which I think was talked about back on page 4 or 5?

@PH1975 posted:

Dave NYC Hudson and/or harmonyards - Has there been any clarification yet on the status (ie. Pass or Fail) of the 2012 Pacifics which appear on Dave’s list of models shown on page 2 of this Thread?

@Dave NYC Hudson PRR K4 posted:

IDK, that is the short list with the Blue Comet and other engines similar. These are definitely different from the K4's by the shells, but got me on the insides. I don't have any of the older ones, and guessing that the newest release of Pacific's would be the same as those older ones. I think someone did have the newest release from the batch that just came out, 2021 that Mr. Muffin's ran some custom runs. I think the one talked about here is on page 4 or 5.

@harmonyards Pat, do you think that those Pacific's are not the same design as the K4'S and probably okay or would there be some research needed there? Also, would these be the same as the most recent release which I think was talked about back on page 4 or 5?

We do not have any clarification yet on earlier Pacifics ……if they have a rear facing motor, chances are they’ll be ok,….BUT, until we see one opened up, it’s in the undecided category as far as I’m concerned, ……again, we’ve done a pretty good job so far on this thread of being 100% factual, with no speculation or guessing,……and that’s the key,…for this thread to be a useful tool, it’s got to be concrete & crystal clear,…..

Pat

Just checked the Blue Comet Legacy Pacific offered in 2012 and it has a Canon in the firebox like the current run. Doesn’t mean it has a spacer though.

Pete

Yep, seeing that black spacer is the pass or fail,…..that is the dividing line….

Pat

@harmonyards posted:

We do not have any clarification yet on earlier Pacifics ……if they have a rear facing motor, chances are they’ll be ok,….BUT, until we see one opened up, it’s in the undecided category as far as I’m concerned, ……again, we’ve done a pretty good job so far on this thread of being 100% factual, with no speculation or guessing,……and that’s the key,…for this thread to be a useful tool, it’s got to be concrete & crystal clear,…..

Pat

@Norton posted:

Just checked the Blue Comet Legacy Pacific offered in 2012 and it has a Canon in the firebox like the current run. Doesn’t mean it has a spacer though.

Pete

Is this different from the newer Pacific's than? Guessing this would need more research as well on both types?

Zhubl's post of SKU 2131300 "wiggles a little" UNION PACIFIC LEGACY USRA PACIFIC #3218

@Dave NYC Hudson PRR K4 posted:

Is this different from the newer Pacific's than? Guessing this would need more research as well on both types?

Zhubl's post of SKU 2131300 "wiggles a little" UNION PACIFIC LEGACY USRA PACIFIC #3218

Well both engines use the same motor in the same location. I think all Legacy steam engines that use the gearbox with the intermediate gear are suspect until they are shown to be OK.

Pete

Guess we need a full blown inspection then.

@Dave NYC Hudson PRR K4 posted:

Guess we need a full blown inspection then.

Yep, eyes in the boxes is the guarantee,…..😉

Pat

@harmonyards posted:

Yep, eyes in the boxes is the guarantee,…..😉

Pat

I'll have to get with you on these as I'm extremely curious. I was already considering sending you my H10 and one of the few Mikado's, that may change just because of overall curiosity needing to be solved.

@Dave NYC Hudson PRR K4 posted:

I'll have to get with you on these as I'm extremely curious. I was already considering sending you my H10 and one of the few Mikado's, that may change just because of overall curiosity needing to be solved.

No problem Dave, we already have a proven track record together, I’m sure we can get it done…😉

Pat

@harmonyards posted:

No problem Dave, we already have a proven track record together, I’m sure we can get it done…😉

Pat

Of course, hard thing is going to be finding where the H10 is at. I moved stuff last month and not sure where that wound up. Finding the NYC Pacific or the B&O from Mr. Muffin's is a piece of cake. See what I come up with on Friday night into Saturday.

We’re in the trenches knee deep fixing these K4’s …..12 total have received the fix, of that 12, ….5 were completely skipping the gears, and would either not move all together, or only move an inch or so……The fix has saved all of them….Of minor mention, the K4’s with the long haul tenders did have a design change to the gear box, HOWEVER, they still not address the shifting gear problem. I’m not sure what prompted the change, but on the long haul models, the gear train is flipped to the other side,…..but again, it did nothing to mitigate the issue,……David Ross’s original beta tester is on it’s way home after many hours of testing ( his was skipping bad too)………..I’ve also included a picture for those who had asked how the part gets made so I’ve added a picture of the part being made, before it gets brazed together for the final machining …….also, I’ll post up a video of one of the gear boxes that was the worst one I’ve seen so far that the worm was completely missing the worm wheel,….that one got fixed too,…..

Pat

That is strange that the gearbox got flipped around as if that would make a difference. Wasn't there a post within the last few months about an old postwar motor that it didn't matter which way it faced, it would still work the same? Hey Pat, of all the engines, I am guessing that none were un-run, all have had some hours logged? It would be weird if a fresh out of the box went right to grinding gears. I guess we'll see what happens when I send you my K4's, whenever I get around to that part.

Tomorrow Pat should receive my H10 6-84954 PRR #1773 from the Coal Hauler set, and the Pacific 2131700 Mr. Muffin's NYC #3330 to take a look at. After they get fixed and pop back over here, I will most likely send out one of the K4's and one of the few Mikado's I have for him to get an in depth look at and fix. It will be interesting to see the comparative differences and similarities between the gearboxes and what potential disasters would be waiting for all who have any of them.

I'm actually curious though the difference between the TMCC K4 1361 6-38025 and the newer K4's? I guess the original K4's were Lionel's design whereas the newer ones are all from the K-Line tooling?

@Dave NYC Hudson PRR K4 posted:

That is strange that the gearbox got flipped around as if that would make a difference. Wasn't there a post within the last few months about an old postwar motor that it didn't matter which way it faced, it would still work the same? Hey Pat, of all the engines, I am guessing that none were un-run, all have had some hours logged? It would be weird if a fresh out of the box went right to grinding gears. I guess we'll see what happens when I send you my K4's, whenever I get around to that part.

Tomorrow Pat should receive my H10 6-84954 PRR #1773 from the Coal Hauler set, and the Pacific 2131700 Mr. Muffin's NYC #3330 to take a look at. After they get fixed and pop back over here, I will most likely send out one of the K4's and one of the few Mikado's I have for him to get an in depth look at and fix. It will be interesting to see the comparative differences and similarities between the gearboxes and what potential disasters would be waiting for all who have any of them.

I'm actually curious though the difference between the TMCC K4 1361 6-38025 and the newer K4's? I guess the original K4's were Lionel's design whereas the newer ones are all from the K-Line tooling?

2 of the K4’s I worked on showed very little use,…..in fact, the grease ( if you can call it that) was still just as translucent as when it was pumped in,……..now all K4’s that have the fix installed sport Mobil 1 full synthetic grease ……

Dave, I believe we’ve seen all of the K4’s right up to the bitter end. They all lack the big fat spacer that gives us that warm fuzzy feeling with these gear box woes,…..we condemned the entire line, many thanks to your help keeping the list straight…..

There are now 16 K4’s ready to go home to their owners. As I noted previously, some were skipping the gears completely, BUT, all showed some signs of the “gear shift” ……now the gears can’t shift, and will have a long happy life,……😉

Pat

This Tuscan K4 was one of the worst offenders,…..the gear shift is blatantly obvious,…..this K4 wouldn’t even move,….you could barely even hear the gears trying to grind, it was so far shifted from the worm shaft …..

Pat

@harmonyards posted:

This Tuscan K4 was one of the worst offenders,…..the gear shift is blatantly obvious,…..this K4 wouldn’t even move,….you could barely even hear the gears trying to grind, it was so far shifted from the worm shaft …..

Pat

Holy cow...😳

If there was a Nobel Prize for model railroading, you and Dave would get it! I think this is important work you two are doing...👍

Mark in Oregon