Sick 36T Shay

[armorsmith]

Well, I posted last week asking about lubrication for the Shay and Climax loco's. Our club did a show in Dothan, AL this weekend and all went great until I went to run the Shay. My Shay is a 2 truck 3 cylinder 36 ton Shay P/N 81196. When put under power all the cylinders, valve gear, bevel gears and wheels turn, but the shay will not move. It almost appears to be supported on something even though it is not. Any attempt to manually rotate the drivers feels like all the gearing in the power truck is connected ie.. lots of resistance. Anyone have any ideas (besides sending it back to Bachmann)?

Thanks,

Bob C.

[Alex Butner]

I'm no expert but you might want to ask Bachmann. I don't know if that's helpful but you might want to give it a try. Also, I don't own a shay, so I can't help you. Sorry.

[Loco Bill]

Bob,  How is it that the wheels turn but the unit will not move??   If the wheels are turning and the unit is on the tracks it should move.  Makes no sense or I do not understand your problem. If you put the unit on the tracks and the wheels turn on both trucks, check to see that both trucks wheels are moving in the same direction, if not they may be working against each other.  wired wrong??. 

If the wheels turn when lifted  off the track, but stop when placed on the track then the problem is the gears inside the truck or both trucks.

I am sure you checked for somthing out of place under the unit, but there may be an obstruction.  Turn the unit upside down and use a straight edge to check along the underframe to see if somthing is stick up which might prevent movement.   

Good luck

[armorsmith]

Bill,

After putting 10' of track down on the work bench and doing some testing here is what I found. She will run back and forth for a few cycles, then the rear truck will fail/lock/bind. When this occurs, it will stop the loco from forward motion with the front truck slipping on the rails. Also, the jack shaft will rotate inside the bevel gears on the rear truck. Sometimes reversing direction will clear the problem, and sometimes it takes a little nudge. Either way, the rear truck seems to be the issue.

Would you recommend a return trip to Bachmann, or purchase the aftermarket trucks and do the repair myself. Also, can one truck be replaced or do they need to be done in pairs.

This is kind of disconcerting considering I purchased this at the South East Garden Railroad Show in Dalton, GA this spring as NIB.  This was the first opportunity I have had to run it since I purchased it.

Any suggestions or recommendations are welcome.

Thanks,

Bob C.

[Jon D. Miller]

Ah, the old NIB locomotive that could be up to 11 years old!  The Pardee & Curtin 36 ton was introduced in 1998.

First, It's only the front truck that provides motion to the cylinders.  The drive shaft from the rear truck is "free" wheeling and does not supply motion to the cylinders.

Sounds like your problem is within the rear motor case.  Turn the locomotive over. Support it properly.  In fact you can use the top half of the clam shell packing to support the locomotive.

Remove the bottom cover from the rear truck.  Check each of the large nylon gears, one on each drive axle.  Look for a split drive gear.  Given the potential age of the unit it is very possible that one of the main axle mounted drive gears has split.

Another way to check the rear motor block is when the locomotive is upside down and supported apply power to the rear truck.  You can do this by touching the two wires that would come from your power pack to a driver on each side of the motor block.  The motor should run and the wheels turn.  If when applying power the wheels won't turn, i.e. the motor will not run then there is a problem with electrical pickup from the rear wheels to the motor.  Also, understand that the two motor blocks share power.  So since your rear motor block doesn't run smoothly then there is a problem with power flowing from the wheels, through the pickups, to the motor.

Check the rear motor block and both the main axle drive gears and electrical pickups may identify the problem.  If you can't find the problem then, for you, the easiest solution is to contact Bachmann and make arrangements to return the unit for correction of the problem.

One of the "Enthusiast Children"

JD

[armorsmith]

Bill,

This evening I took your advice and turned the loco upsidedown in the top half of the clamshell packing. Removing the cover from the rear truck and doing a visual inspection both with naked eyes and with an optivisor, I can detect no cracks in the drive gears.

Applying power to the upturned trucks (low power, slow speed) and all seemed well....for awhile.  I was able to load the truck by applying pressure to the alligator clips I was using to power the trucks with little or no change in the function of the truck. After a short while I began to notice that the front truck was not running.  A minor repositioning of the rear truck seemed to repower the front truck, however I believe this also indicates that there may be an internal electrical issue, as you stated earlier that both trucks share power.

Thanks for letting me know that the rear truck is independant of the line shaft and that the bevel gears are supposed to rotate independantly. This is another point I will have to make sure to lubricate now and again.

I think at this juncture I am going to contact Bachmann and arrange for a trip New Jersey.

Thanks for your help and interest in a novice.

Bob C.

[Loco Bill]

Bob,

You owe your thanks to Jon MIller (JD) as he is the one who gave you the excellent response and not me.   Novices are always welcome here and there are no dumb questions.   Good luch with your repairs!

JD, As always a great response!   Much appreciated by the board members and myself.

Bill

[Jon D. Miller]

Bob,
Now we are getting to the heart of the problem.

Electrical contact between each truck and the locomotive is through two spring loaded plungers at each truck.  These plungers make contact with a small brass ring that is wired to the PCB of the locomotive.

Chances are that since the locomotive, given it age, has not been run the brass rings have developed a slight coating of oxidation.  Also, the electrical contacts that run against the back of each driver could also have some oxidation.

Look at page 26 of your Owner's manual.  There you will see the ball bearings that make contact with the back of each driver.  What is not illustrated are the plungers, mounted next to the king post, that transmit power from the motor blocks into the locomotive.

The intermittent power to both the front and rear trucks indicates that these plungers are not making constant contact.

Do you have any Conducta?  If so, place a drop or two of Conducta on each of the ball bearing pickups behind each driver.  Now, getting Conducta to the plungers located on each side of the king post may be a problem.  You can try placing the locomotive on its side and putting Conducta around each king post in an attempt to get it to migrate to the plungers and the brass contact ring.

If the locomotive were mine, I'd place the engine upside down in the top packing container and slowly run the unit.  Keep the trucks as level as possible and be careful not to allow them to pivot to far so that the drive shaft slip joints will disengage.  As the locomotive runs I'd work the trucks slightly side to side trying to break through the oxidation that may be on the contact rings.

I think that if you were to do this for a while contact could be restored at both trucks.  A more positive way to correct this problem would be to remove the trucks and clean the contact plungers and brass contact ring.
This may be more work than you would want to take on. 

So, if after doing the above the locomotive will still not conduct power without a lose of contact then the unit will have to be returned to Bachmann.  Most likely they'll just take the trucks off, clean the contacts and return the unit.

As a aside.  These contact plungers did give a problem, in many cases right from the start.  Many folks, myself included, eliminated these contact plungers and hard wired in their place.  Also did this with the Climax that uses the same system to transmit power  to and from the motor blocks.  Once hard wired there will never be a problem with intermittent power.

Good luck!

One of the "Enthusiastic Children"


JD

[armorsmith]

Bill,

Thank you for the correction and assistance.

Jon,

Thank you for your excellent instructional dialog.

Yes, I do have Conducta (had to look in the tool box to see what I actually had), and I have already done the ball contacts at the back of the wheels as per the instructional video (yea....VHS) provided with the loco. Neither the book nor the video mention the additional contacts at the king post.

Yes, you are correct in that I do not think I am ready to disassemble the trucks from the loco quite yet, so the upside down and run option will be tried.

I apologize for confusing you and Bill (the wife says I live in the 51st state....the state of confusion ).  You both have provided invaluable information on several questions I have asked.

I also have the Climax, purchased at the same time, so I will watch it for similar issues. The Climax did run flawlessly for about 3-4 hours at a train show last weekend, so I am hoping to not have these issues in the future.

Thanks you both again.

Bob C.

[Jon D. Miller]

Bob C.

Did you ever get the Shay so that both motors would run?

Just wondering.

One of the "Enthusiastic Children"

JD

[armorsmith]

Jon,

I seem to have beaten it on the bench.  I have a club meeting tomorrow and I am taking the Shay with me.  We use Aristo TE's on the club layouts, but I got it to run with an Aristo PWM from a starter set.  I am going to bring it also and see if I can get some running time while we do the yard work in preparation for the 100th Anniversary Celebration of the L&N Station in Milton, Florida (yep, a little plug ) next Saturday and Sunday. Will be running both days to the enjoyment of everyone.

Thanks for your interest, I should have posted back.

Bob C.

[armorsmith]

Jon and Bill,

Just a note to continue...

Took the shay to the club meeting and it ran great for about an hour. Good start!

The shay performed perfectly for the Centenial Celebration of the L&N Station in Milton, Florida.  Put it out with a five car (scratch built with real logs) and a hack.  She ran flawlessly for about 5 hours.

Thanks both of you for your suggestions and advice.

Bob C.

[Jon D. Miller]

Bob C.

Thanks for the additional report.  Seems like you've the problme solved. Have fun with the Climax and Shay.

One ot the "Enthusiastic Children"

JD