Hornby Thomas gears no longer meshing properly

[Paul26e]

Hi to all at RM Web

 

I wonder if someone could help me? We have a 7 year old Hornby Thomas that has not been used much.

 

Tried to run it yesterday and all was fine for a while. Then it started making a grating sound and then stopped altogether.

 

On inspection it seems all is fine with pick ups but the motor is no longer meshing with gear on driven axel!

 

I have found Hornby service sheet on line and no parts appear to be missing or broken. I have taken it to bits and there is a lot of grot on gear on motor. Would this be enough to stop it meshing?

 

Anyone experienced anything similar with any recent Hornby 0-6-0?

 

Thanks in anticipation

 

Paul26e

[Simon G]

This is pretty common on recent Hornby 0-6-0s.  If cleaning it doesn't work then what you probably need to do is to replace the worm and gear wheel.  If you check the gear wheel carefully, you will most likely see some signs of wear, usually the teeth being worn down in the middle.  The worm & gear heel can be bought as a set - X8199 is the code number. and you can get them online from a number of suppliers, typically about £3 for the pair.

[Londontram]

With mine for some reason even after changing the worm and wheel mine still didn't quite mesh and in the end I popped the motor out the cradle and placed a flat piece of 5 thou plasticard between the top of the motor and the cradle which seemed to push the motor down a little and I've not had any more trouble since. my worm and wheel came from Pete's spares (usual disclaimer) and was about £5 with p & p 

[Il Grifone]

Plastic gears are prone to rapid wear, especially if not aligned correctly and/or the lubricant has hardened. I have had them break up all by themselves.*

 

There was never any problem with the brass gears used in the past.

 

*The plastic gears in VCRs seemed to have a life of about 10 years. I remember we have the same problem with UHF tuners in Italy. Changing between The RAI 1st and 2nd channel was done by switching between VHF and UHF. with the arrival of more UHF channel the UHF tuner needing retuning for the first time in years. The early tuners with brass gears were quite happy, but the later ones with nylon gears quickly failed. Repair involved bodges involving wire melted into the plastic or a new (expensive) tuner.

[jwealleans]

I'm not completely familiar with these mechanisms but I have had other Hornby locos where the motor fixing screw has loosened enough to allow the motor to lift slightly and come out of mesh.  It's usually accessed from underneath.

[Simon G]

I'm not completely familiar with these mechanisms but I have had other Hornby locos where the motor fixing screw has loosened enough to allow the motor to lift slightly and come out of mesh.  It's usually accessed from underneath.

These 0-6-0 chassis do have a single fixing screw, but it is on the top of the chassis, rather than underneath.  It is worth checking that it isnt loose though!

[Londontram]

Its actually not a bad running little chassis with its compensated rear axle and I believe is used under a number of Hornby body's.

     I used a pair of fine pin nosed pliers to ease the worm off and pushed the new one on by just pushing the motor down onto it, the motor shaft will not push out of the motor so don't worry don't forget to note how far the old worm was on the motor shaft before you remove it. The gear wheel can be a bit tight on the shaft and you will need to remove one of the wheels from the axle and I've found its easier to remove the insulated wheel which sits on a rubber bush on the axle than the non insulated one (the insulated side is the side that has the brass pickup strip looking forward from the back of the loco this is the right side) you will also need to slide off the brass bearing while you fit the new gear wheel.

    To remove the gear wheel I used a pair of long nose pliers behind the gear and gently tapped the axle out and again tapped the shaft onto the new gear wheel by once starting it of sitting the gear wheel over a slightly open mini vice (or pair of pliers) and tapping the axle down until the axle passed though and the gearwheel was in the right place, before you put the gear wheel or driving wheel back on make sure the brass axle bearings are back in place.

One word of warning when you remove the plastic "keeper" plate on the underside of the chassis to release the axles be careful as under the rear axle are two very small coil springs that once the axles come out can drop out (and sods law means they surly will) and are easily lost, these springs are needed for the rear axle compensation so be warned. Don't forget to correctly quarter the driving wheel when you tap it back onto the axle, I did mine by looking at one of the other axles to see which wheel was leading IE quarter of a turn ahead on one side to the other then just using a bit of brass wire passed through the spokes on the still fitted wheel and lining up with the correct relevant spoke on the other I was able to correctly quarter the driving wheels first time, don't worry though if its not right you can just pull it off and try again. Once the axles have been refitted and the connecting rods fitted as well just push test the chassis before fitting the motor you will soon see if the quartering is out slightly as the chassis will bind Here is a link to one of my threads that show some work I've been doing to convert one of the chassis to a 0-4-4 from an 0-6-0 and you can see the pickup strip in some of these photos http://www.rmweb.co.uk/community/index.php?/topic/77470-rtr-locos-to-caledonian-locos-class-439-104-782-and-others/?p=1500485  Good luck, Steve

Edited August 4, 2014 by Londontram

[Paul26e]

Hi

 

Thanks for all the replies.

 

Will order new motor and attempt to fit.

 

Thanks

 

Paul26e

 

[dragosmp]

On 04/08/2014 at 10:43, Londontram said:

Its actually not a bad running little chassis with its compensated rear axle and I believe is used under a number of Hornby body's.

    (...)

 

Reviving this old topic to give a Kudos. My R382 Duck (from Thomas the Train) just lost traction and I went through the debigging process. I took advantage of the loco being side-lined to do a thorough clean. Turns out, after disaaaembling and reassembling everything, the fix was a simple plastic piece to push the motor worm drive down a bit. I adjusted with the fixing bolt a "right" ammount of press, as too much puts too much pressure on the traction wheel and the motor is bogged down.

 

Great guide, nicely explained

 

*EDIT: aded a pic of my "fix"

Edited January 23, 2021 by dragosmp