Faulty Model Train Autopsy | Can They Be Fixed? 

Thanks Sam! my Adams Radial went belly up last year and I figured it was the motor, I remember you saying they were weak so I took it out and pulled the chassis around with another loco to see if there was any friction in the mechanism, even without the body on it rolled around OK, I even contacted Oxford to see if they had any replacement motors, I was begining to think it was just an expensive paperweight! After watching this I figured what the hell, I went into the garage and stripped it apart and cleaned out the old grease and it's running as good as new.

You have proved that a good clean and lube will improve running.Showing how to take apart and of course put back together is a timesaver.Thanks Sam.

Thank you Sam. As an old mechanic, and a guy that used to repair HO, HON3 and T scale engines a long time ago, I really enjoyed this video. I used a needle oiler all the time. With regular straight 20 wt oil. Oh, way back when, I would purchase Atlas turntables, disassemble them, and use the can motors in locos. I anchored the motors down with early GE heat resistant silicon sealant. I'm sure there is better stuff today. Sorry for going on so.

Sam looks at anything Heljan, 'Yep faulty' Lovely video Sam's Warwells

Hi Sam, two things to check magnets probably gone week you can get a machine on line to re- energizer the magnets. however far more likely is weak brush springs/ dirty commutator. Great video, stay safe.

You normally seem to fix them pretty well Sam , so I’m gonna say yes you can XD

I miss your old servicing videos, you should do more. Don’t remember seeing one for years so when did you release the one you mention at the start of the video.

You should do a follow-up to this and see how they perform a while later, comparing the different lubricants. I'm surprised you've not tried WD40 :)

Thanks for that, I've just recovered 2 Adams Radials that I bought cheap as poor runners and could never get going properly, one was worse than yours and the other about the same. Both gearboxes stuffed with that ghastly grease, both running very well now.

A small (cheap) ultrasonic cleaner can also be useful for cleaning intricate parts. I managed to revive the motor from my Bosch drill by ultrasonic cleaning. The brushes/commutator were dirty causing sparking. As a sealed unit I wasn't able to dismantle it, but it did have some ventilation slots in the motor casing which enabled the ultrasonic cleaner to do its job.

Hi Sam, I found this video last night and it's been really useful. I picked up an Oxford Adams tank from eBay as a non-runner last year. On arrival, it was completely dead, a bit of fiddling around and a clean-up did get it running - but barely. The loco would inch forward and backward and it could just about move one coach. I gave it another clean, check the chassis would roll, etc but no change in performance. I assumed the motor was kaput. Having watched this video I thought I'd give it one last go. I followed the strip down - I love the trap door - and removed all the original grease. I oiled up the mechanism and reassembled and hey-presto the engine is now flying around my layout pulling 6 coaches with ease. Just to note the torque on mine does seem to be pretty good, if put my finger infront of the loco I'm getting some good wheel spin. Many thanks for this video, it's saved a loco from the scrap heap!

Hi Sam, I've recently had a revelation. I bought an ultrasonic cleaner for use with car gearbox internals and bicycle parts; it's great for those purposes, but then it dawned on me that I might be able to use it for model parts. For the large vehicles (cars and bikes) I use it with cleaning agents dissolved in water, but for models I tried it with both IPA and automotive brake cleaner because they dry off almost immediately. The results are fantastic - ten minutes is enough to remove almost any contamination, leaving components perfectly clean without any effort. I haven't tried it yet, (and if anyone does it will be 100% at their own risk) but there is a reasonable possibility that I could just drop a complete motor into the tank and let it be cleaned both internally and externally. So long as it is allowed to dry thoroughly there may well be no problem with this if you make sure that the bearings are lubricated again before running. I reckon that the very smallest of ultrasonic cleaner would be perfectly adequate if only used for models.

Saw two Adams in a model shop yesterday with a big discount. Was tempted as they looked lovely. Very glad to see this. Cheers!

Hey Sam. Ive been enjoying your videos lately, great physics today. I have a video idea or layout addition, but I’d live to see you make a station on the layout.

Great video, Sam, as per usual, they both certainly seem a lot smoother running. Would be great to see you servicing a couple of diesels too...

I know your probably not going to see this comment, but I really liked this type of video as well as the one similar to this that you did on The LMS 10000 and Flying Scotsman. I also used to enjoy your servicing streams, and we haven’t seen a series of livestreams from you in ages generally speaking.

This can be a very satisfying part of the hobby, especially when you have bought a very cheap reject and fix it. One dodgy swap meet trader sold me a dud. Discovered how to fix it easily. So enjoyed telling him at the next meet that he sold me a dud but I fixed it simply. Of course without telling him what fixed it when he asked. This was a Stewart F7 A unit with a Kato drive. Nearly unknown to have a problem with such a high quality item. My speed and amp draw testing showed it to be much slower and had much higher amp draw than the rest of my fleet of Kato F units. Disassembly testing showed the motor only was fine. Turned out the universal shafts to the gear towers were different lengths slightly and meant for different ends of the loco. Once the shafts were in the correct ends the drivetrain no longer was jamming up. Result , a beautiful running loco as usual for these Kato drive locos at the pinnacle of good running.

What is important to me,is the details on the mechanism.If it has a flywheel,quality of motor,proper axle bearings,the weight,is it noisy,etc.This info is not usually given,so it nice to watch your informative videos.

Fantastic video Sam - I really enjoy these servicing and repair videos. I've got an Oxford Rail Adams Radial that also runs fairly slow so (if I'm brave enough) I might follow what you did and see if it improves.

Hi Sam, I love all things Prairie, my Hornby large Prairie arrived and ran well odr seconds from new... until it threw a coupling rod! Poor build quality seems to be normal these days. Even my new and eagerly anticipated Dapol Mogul dropped it's underframe on the tender when running in.

Loved the video Sam can't wait for the next one have a good week

Sam. Keep these coming as they give a good idea of the various mechanisms. In Australia you cant just send faulty ones back, you have to repair them yourself. I have a Hornby Castle, not that old with a cylinder block fouling the con rods. Turns out the cylinder block is in at least 5 parts to be assembled. Getting the parts in exact alignment is very tricky. Love you to do a strip down

I'm really amazed by your electrical and mecanical skills young man ! For me, everything more complex to use than a screwdriver is beyond my abilities... Find the idea to check the lubricant requires some experience I clearly don't have, you teached me something today ! By the way, I have adopted the easy way to solve those problems on mine : I've bought the Hornby Adams Radial and I am waiting for the Dapol prairie... Anyway, it's a good thing to find simple but astute solutions to this problems. Even if the Hornby Prairie is clearly underpowered. For my own, I had botched the insall of a DCC decoder in my B2 Peckett, the wiring is too flimsy and I cutted it off by trying to fit a decoder. I'm waiting for a wired decoder to solder in her, I have no other solution except sending it back to Hornby to get it repaired. For my Dapol B4, retrospectively, I am happy to have bought one with the decoder prefitted... Thanks for the video !

Hi Sam, Very interesting 'investigation' and your results speak for themselves. I have exactly the same engines. The Adams Radial ESU - DCC sound fitted had the 'incline' problem but the running is fine. The Large Prairie was another story fixing the bogie and pony trucks and also the keeper plate friction on the axels. It was dripping with oil but I didn't check the gear oiling and need to investigate as you showed. The pulling power and rail contact is related to the weight and the Prairie does benefit from adding some but doesn't fit the job as a shunter on my RR. Nice models but fragile & picky pullers. Thanks for showing the in-depth chirurgical improving works !

Thanks for this Sam, it has been a lifesaver! I went to Frome model shop, after they relaxed the lockdown rules; and they were selling their Oxford Rail's Adams locomotives off and so I bought a couple, EKR and the BR Early (only £50 each). Surprise surprise I got exactly the same problems you experienced, The EKR got really really hot and run really really slow, barley moving sometimes, the BR Early just ran very slow, it did not get hot. I have followed your video spending the whole morning doing this to my EKR. When I opened my EKR, it looked like the gears had been coated with trickle not lubricant and an excessive amount of it to boot. It took me an age to clean it all off everything, it was everywhere, and I mean everywhere! However, having cleaned it all off and given it a service, it now runs well in both directions, - hmmm how do you measure well? I am really pleased it does not get hot now and runs at a constant if a little slow speed in both directions. But if you give it anything to pull, it struggles and gets a bit warmer, as you say the motor does not seem to be up to the job, but it runs noticeably better than it did before in both directions. Now I just have to do it all again to my BR early version.

Glad to be back i can already tell I'll enjoy this.

Thank you Sam for making this happen !

John here-I'm on the other side of the pond modeling in On30, but your videos are a real help, and just the idea of not being afraid to disassemble a loco is compelling. Now, if you would attempt a Bachmann On30 2-4-4-2.................Thanks for your video!

I reckon you should do another video upgrading the motors in these locos and see if they improve like you did with Smokey Joe. I liked this video seeing the mechanism in detail!

Very interesting vid. Re. the Oxford Adams Radial I emailed their technical department a few weeks ago and was advised to clean the gear train. I have 2, one ran fine but the other was slow. After a clean as you have done it runs much better too - same issue with lack of viscosity. It would appear that the problem is something Oxford are aware of - they were very helpful.

Looks like another banger video has been given to us. Thanks Sam.

This is great! I missed the latest couple of vids so I’m here apologising! But this was really fun, great video!

Nice work! It would be interesting to try swopping the motors - as you did to a different loco in a previous video

Another interesting and informative repair! You need to do more of these. I have a brass hybrid Broadway Limited loco I bought for a fantastic price because it would not run. Turns out the lube had gone solid and after a nice clean it is now a nice runner.

I actually think this is one of the most enjoyable parts of the hobby. Nothing beats the satisfaction of plonking down an old stinker on the track and see it purr!

hi sam,thank god i still have my Triang jinty and dock shunters that do not fail.keep up the good work

I think this is the best video you've done so far Sam.

Hey Sam a very interesting tear down, my suggestion would be to see if you can find a way to recharge the motor magnets, this will improve power and reduce current consumption. Is there room to get a couple of tiny neo magnets in there?

Hi Sam, thank you for a great video. I have a super slow running Oxford Dean , I will apply your wonderful knowledge to this loco, maybe it is just what it needs. Thank you Sam Kind regards Chris.

Great video Sam. I really enjoyed watching you service these locos especially when I commented on a previous video as to whether you did or not. You certainly can teach us a lot. Now the next question is….. are you going to replace the motors on these and make them worthy to run on your layout. If you do I hope you show it as I would definitely love to see it.

Doctor Sam is in the house! I do like that Adams Radial. I have a Dapol Mogul on it's way to me. I'm so looking forward to adding it to my collection!

It’s great you got those two working as they should Sam, it’s sad to see poor-running locos sitting on shelves or in boxes so this is great for people that own items like these. For me, I’m more of a diesel person but I’m thinking about purchasing a steam loco so thanks for sharing this video 🙃

Regarding the Adam's Radial tank engine, I purchased the same one ages ago but it hasn't been run much. I guess it will require a strip down and removal of old grease as i guess it will be pretty solid by now. Lubricant wise I know woodland scenics do a great range of gear grease for model locomotives.

An interesting exercise Sam, although why you should have to see such a thing on these newer models goodness only knows. Excellent as always...Bob

As for the issue with the adams radial I had a similar problem with a 50+ year old full metal 2-8-2 mikado locomotive from mantua and the problem with the slowing down was due to a gear that was cracked for who knows how long that after it ran for a while before I knew what was wrong the gear would expand and thus stop the thing dead in its tracks even though it could pull 30+ box cars

I'm a newbie and my soldering has been described as a 'bobo' or 'a big ole 'scab'. You have inspired me to go dig in my hopeless loco.

Sam From a antique shop I got a really strange wagon that has chains in the middle It has the Couplings like your Mahno western train

Brake down of model trains, fantastic, very detailed and informative

Always good when you can fix something yourself you get a good experience and a whole wealth of knowledge from doing this sort of stuff I find.

Some lovely tips and advice to fix ho locomotives, very useful!

Hi Sam, Great review, can't they just upgrade the motor, They charge enough money when you buy them , (Love the air line impression) All the Best Brian 🤗

Found the Prairie strip down useful/interesting, didn't even know you could get into those gears and I'd had the bloody body off an hourish prior to lubricate it before running it in.

my OO Gauge Terrier in the LBSC Livery had that same problem, my Dad had to clean off some of the gears, cause their was Way too much lubricant on the geartrain...

Always good to see old locos get restored!

It's amazing what a good clean up of excess oil can achieve, even if it only solves part of the problem! What type of motor was in the second engine you investigated? 3 pole, 5 pole, coreless and would that have made any difference etc? Best, Pete.

Sams Mum : I keep getting metal flakes on my dishes? Great video Sam. Knowing how to fix them will take so much frustration out of this hobby, especially at the cost of locos. You're the man Sam!!

Very interesting. You certainly couldn't have done any more with them. But, honestly, an older model with an XO3 motor would haul 4 old coaches with sleeved wheels better than that. The magnets in then new motors look a bit undersized. Maybe that accounts for the lack of torque. I wonder if there is a high torque replacement out there. Beautiful looking models though 😊👍

Hi Sam Great video, thank you. My Large prairie has been bad from new. No pulling power and gradually gets slower and slower. I suspect the motor but have changed it with no real improvement, also the gearbox to worm drive is not particularly good... sadly as I love the model.

Hi Sam. Great video, very informative. You stress the importance of good lube so can you please tell us what your recommended lube oil and grease is?

I know this is years on but get a cheap thermal camera adapter for your phone. Its the absolute simplest way to troubleshoot anything on the power scales that these trains run at. If anything is binding or shorted it will show up clear as day.

great video. maybe you could explain the different parts of the motor / mechanism and what they are called. or a video showing the anatomy of common diesel and steam locos.

I ran my oxford radial tank the other day, seemed very slow. Needs a new DCC chip now, but that's a separate issue. So yeah, I'll be doing this fix soon. Probs fix my split chassis bachmann b1 at the same time, no idea why that suddenly cut out. As for KR Models, my GT3 I took the front pony truck off so I could get at the screws to disconnect the lower front light (temporarily, as I'm gonna have to rewire the pcb in the tender to make it run off the 2nd function output so directional, as well as adding red lighting gel to it so its a rear marker light), reassembled it, screwed it tight, and it still turns very freely. So you must've reassembled it wrong when you disassembled it before first testing it. So in the future, maybe disassemble the loco to see what the mechanism is like after running in? The cavity is for the decoder. As per the small box area in the sentinels, and bachmann did similar but also chose to fill the void with a weight for better DC performance. It's a shame the large prairie still runs badly. I'd only be tempted by one if they do it in GWR lined green with the BRITISH RAILWAYS lettering in the GWR font, as I have seen that done. I've got a SR malachite green terrier and a LNER apple green a1 and a LNER unlined black b16/3 with BRITISH RAILWAYS lettering (I'd love Mallard as E22 in post-war garter blue with that lettering as per the 1948 exchange trials), but no LMS or GWR examples yet.

I think I mentioned this before but it seems that some British OO manufacturers seem to install those small, square motors that look like HO scale slot car motors in their locomotives, even the relatively large road engines. You don't see them in American HO locomotives, not even in small switchers/shunters. In N scale locomotives yes, but not in HO scale. Too much load for them. Those motors you examined aren't much bigger; so, to me, they could be a slow burnout risk trying to carry the heavier weight of an OO loco and their larger drive trains and pulling the weight of a consist. If it is possible perhaps swap them out for larger motors?.

Awesome job. On a side note, will you be doing a review on the Caledonian 812 coming soon

Great video, would love to see what happens if you fit a replacement motor.

More! More! Sam. I've just checked on other comments but no-one seems to pick up your disparaging remarks about the 'lead-free soldering Chinese people' - What do you recommend for solder? Leaded? Or is it just dry joint problems? Excellent video - I am truly delighted when there's a remarkable improvement! Roger King (below) must have read my future mind as I watched you cleaning those small parts. A few years ago and for just £20. I bought, from LIDL(!) a SilverCrest SUR 46 B1 Ultrasonic Cleaner - made by HOYER HANDEL GMBH. Kuhnehofe 5 D-22761. One is, I think, supposed to use "water for topping up lead-acid batteries" in it - there should be debate on this subject - I have thought of using such stuff as Meths, or White Spirit instead (Roger King has used IPA [isn't that Indian Pale Ale?!] and automotive brake cleaner) 3 push-button controls (Start, Set, Stop) and fitted small basket - probably takes about a cup - or less - whatever.

Great video, Sam. Good job.

Hi Sam. I have some trains you might like for restoration! A class 67 in particular. Missing front bogie and a few other things. Was my childhood train. It’s a Wrexham & Shropshire edition :)

Sam, what about the over hearing issues on the adams? And how long did you run it around before any issues arouse again since you done a lubricstant change? Please see this and let us know feedback on this issue.

Fascinating! I wonder what Hornby and Oxford Rail have to say about their defective motors?

Great video Sam! A question... Why do you check the gauge inside the wheel flanges? The gauge is actually between the insides of the rails so don't you need to check the outside of the wheel flanges? The wheel flanges could be different thicknesses on different locos. (Or even different wheels on the same loco if they're really bad!) Keep up the good work!

Crackin video again sir! Anyway to change or upgrade the motor? It’s such a shame that 2 lovely looking loco’s have such issues..

Hmmm, I wonder, what the serial batch number for the large prairie Sam? Some research Barrie Davies carried out on the S15s found that different batches could have the motor problems that made the s15 notorious, while others were perfect healthy runners. I wonder if the same is true here…

does the worm drive in the Adams Radial have the same hex fit in the flywheel that it does in the hornby prairie? if not, could it be the same issue that the LMS 10000 had?

Actually with the gearing on the Prairie do the gears from the worm drive get progressively smaller to the driven axle? I thought they looked like they geared for speed not torque

When I reviewed Sam' I give him a high score for value.Would I pay Bachmann money for one? Probably not, but at this level of detail I can highly recommend him.

I got my old model trains and coaches and whatnot back and has been great but I don’t have my controller so I’m just dusting and cleaning it all So I don’t know what is faulty or not such as my class 390, 68 HST, 2 37s and some steam shunters Have to wait till I get a chance to look in my nans attic

I seem to remember that bad/weak magnets in a model motor can also cause poor running and excessive power-draw; have you ever checked if your models have ropey magnets?

Hi Sam. Very educational. Will Part 2 be replacement of the motors (when you get some in)?

You have so much patience Sam

I'd love to see you work on that BT well tank that thing needs some serious work

Hello Sam, maybe You can improve the performance even more if You reduce the mechanical friction of the plastic gear wheels by honing their flat surfaces with 1500-2000 grid wet- paper on a flat surface?

Am I odd in preferring to fix up, make look good loco's etc than actually building up a layout? I am thoroughly enjoying rebuilding my very very early Triang DMU and still yet have to lay down a working set of tracks other than a test track I have in the kitchen lol Just finished getting the power bogie (thanks to John's superb videos for help) down to its knickers and really taking my time in getting it all right, normally I am a watch collector and restorer but I am loving these little engines :D

Awesome video sam

Hi Sam, just rewatched this video. My local model shop is selling Oxfords Adams radial tanks for £50. Fully aware of the faults addressed I am still tempted but not 100% sure. Is your radial working well 3 months later after removing that old grease? Im thinking this just in case I get one and it is the same. I’d like to know if it would possibly fix them for a long term or not. Cheers Matthew

Great job. I would never have attempted that myself.

On the Hornby loco, those look like neodiddlyum field magnets. I'm wondering whether at some point in their life they got toasty enough to lose strength (which begins to happen at about 100°C). They look awfully close to the rotor windings

Hey Sam, I recently bought the BR green Hornby prairie and my one runs fine. So I’m assuming maybe a bad batch is to blame with the fault on yours?

Is there a video where you fix the springing in the Oxford Adams Radial? I've been meaning to fix that in mine myself. If not, what's a good tutorial to do so?

Thank you for this Sam. I don't think it's worth me investing in one though as I would need it to haul a 10 wagon coal train up a 1 in 30.. If you can advise on a great western Loco that will be better that would be very much appreciated. Great video's Sam.

enjoyed watching. Wanted to see if the prairie can be improved. I am sticking with the older one. Would like to see what the new one runs like with a replacement motor. That screw holding the front bogie is a bad design. These locos can be described as a curates egg partly good partly bad. Thanks for showing. Regards Paul.

Hi Sam, the other day I stumbled on a RU-vid channel called oobill, he specializes in repairing faulty locomotives and I noticed he uses a product called Electrical Contact Cleaner. It comes in a pressure pack can and has a long nozzle. It might be worth checking it out to see if it is worth using. I have not yet tried this product mainly because I have not had a locomotive that needs repairing. Cheers Greg

My Oxford Rail Adams radial tank I stripped it down and removed all the old grease and oil and cleaned all the parts put it back together and it worked a treat. I think the grease they used was too thick

Are you gonna compare the Dapol GWR large prairie tank to the Hornby Large prairie tank?

Hi Sam, video on wheel Quartering will be very helpful.

Interesting video sam thanks.

A thought regarding the 'sticky grease' - maybe the manufacturer uses grease designed to be used in hotter countries than uk? Regardless, It looks like the motor must be at fault. The lack of friction once you had serviced the loco suggests it can't be anything else. They do look particularly cheap compared to the semi can or full can motors. My money is on the fixed magnets being weak like someone else suggested, or their size/ magnetic field not optimised to the armature? By the way, you don't really need to de solder the motor, you could either buy or make an adaptor that goes in place of the decoder blank/ suppressor board you remove for DCC operation and plug your adaptor in to the female/ chassis DCC socket pins 1 and 5. You can buy 8 pin dual in line headers online for pennies. Then you have a test harness for the future that you can use on all your 8 pin DCC locos and no fiddly soldering burned fingers or melted wire. The same idea would work for other decoder pin types. Finally since both Hornby and Oxford subcontract their manufacture I guess both these locos come from the same factory, hence the mechanism similarity.

Flushing out a gear tower with solvent is a good method of freeing a sticky gear system. However, there's 'flushing' and there's flushing. The solvents don't work instantly on a lot of crud. They need time to dissolve what's in place. Then, you must begin to flush. That means successive dips, shakes, swishes, and then repeating in new solvent until the remnants of the offending material to be removed is truly gone. IOW, this, like many endeavours worth doing, takes TIME.

hi i have an extremely old hornsby steam train, i,m trying to get it working. The motor is receiving power and is spinning well, everything has been oiled however neither the worm gear or wheels are turning. I have no idea how to fix this. Can anyone help?

Oh yeah! This is great!