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Bachmann 2MT in great trouble


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31-450E

 

This loco was find last time I ran it, and that was for the Winston Churchill Train Pack video (3-4 years ago). Got her out today as she is needed for a supporting role again only to find she ran like a pig, initially I discovered that the plastic wheel inserts had swollen outwards and were hitting the coupling rod, fixed this only to discover the driving wheels back and front were lose on their axles!!!!!  Opened her up and found the axles split and the middle driving gear. So cleaned them out and filled with super glue and clamped shut, she is running now but very much a virgin in a brothel 

 

She has been properly stored in her own box all the time, so upset as this is one of my favs.

Any long term fixes?

 

 

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Hi,

As Butler has said this is an almost a standard state of affairs for split chassis Bachmann engines. I have 5 of their early 4MT engines and they all had wheel warp due to the plastic wheel inserts expanding. All I did in the end was take out the inserts, Glued back the wheel weights I cut from the inserts back into the right place. Then painted the metal wheels. The wheels were easy to straighten once the inserts were out. Not perfect but they do pass the squint test just. I must admit I have 2 of the 2mt engines and I have not checked them for several years. Looks like I will be dragging out all my boxed engines to find them at some point.

As for the movement one the axels. The Bachmann 2mt if the same as the 4mt have square pegs on the wheels going into the axels. Unlike the Mainline engines which just had a pin. You can use a little apoxy resin to glue them back in. Quartering is not a problem as there is only a very limited way you an put them back.

Edited by cypherman
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11 minutes ago, cypherman said:

Sorry Mike.

It is a possible fault in all the early Bachmann split chassis engines that use plastic wheel inserts. But they all respond to the same method of fixing.

 

 

Thanks, guess I'll have to dig them all out and check! super glue is holding on my 2MT axels just now, if it fails then epoxy will be used and I'll flatten the inserts out, had this with an old Airfix loco, placed the inserts between two metal plates, headed with hairdryer, left over night, flat but now too big so had to be evenly sanded down.

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6 hours ago, mikesndbs said:

OH no, not the 4MT as well :(

 


......and the B1. Sad to confirm as others have said, the problem can be with all split chassis loco’s. I can also confirm that Bachman have the inserts, but no wheel sets for the B1, as I called them last week.

 

 

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1 hour ago, Butler Henderson said:

I have never had the problem other than with locos I had previously let others borrow so I do wonder if some of the issues are down to the wrong lubricant being used.

 

Never used anything but the original lube and Hob-e-lube

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2 hours ago, Butler Henderson said:

I have never had the problem other than with locos I had previously let others borrow so I do wonder if some of the issues are down to the wrong lubricant being used.

Definitely not so if we make the assumption that Bachmann used an appropriate product. I had enough of the white grease that Bachmann used as standard scraped out of the chassis gaps and keeper plates, that I used it exclusively on all the many Bachmann split chassis mechanisms I wore out by enthusiastic use (A4, B1, J39, V1, V2, Jubilee).

 

It's a short life construction, the plastic axle muff either is pulled loose by mechanical action of the drive being transmitted by the rods if used regularly, or the muffs and the gears crack if stored. And the plastic wheelface inserts swell and bow out pretty randomly; affects some, not others, but saw it on every type of mechanism with this constructional element. (This was all very 'steam railway', locos were 'stopped' very regularly for the latest defect to be repaired.)

 

And finally the nickel plating is way too thin for an intensive operator, and once the tyres and axle stubs and chassis recesses are all showing copper, they are effectively 'used up'. Bachmann as good as acknowledged the short life by making the chassis available as relatively cheap spares: went through several on some locos until - hurrah! - proven steel axle wheelset and wiper pick up mechanisms became standard in their range.

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It seems to me that this is a very inconsistent problem - I bought one of my Bachmann Ivatt 2MT tanks when they first came out back in the mid-‘90s, it’s been a regular performer on both home and exhibition layouts ever since and still runs well. A second Ivatt bought some years later pretty much fell to bits, needing a complete new wheel set within 2 years.

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7 minutes ago, Colin said:

It seems to me that this is a very inconsistent problem...

It is. Very variable indeed, hallmark of a low cost production process. The chassis casting and plating quality was poorly controlled, and the mechanism plastic variable. Not just the gears and axle muffs, but also the keeper plate and assembly plug mouldings, some soft but relatively tough, others hard and brittle. Just my opinion, Bachmann used this mechanism design for their initial OO market probe to keep cost down, in combination with the use of the existing body tooling left with Kader by Palitoy. (Credit where due, good motors, never had one fail, and the coil springs on carrying wheels were all salvaged and find continued use cut into short lengths, mainly on Hornby leading bogies.)

 

I squeezed all the possible life from my split chassis mechs up to final wear out, by combining the best parts off multiple mechanisms, until I had worn out one of the last unique parts required for a particular mechanism. (I didn't think at the time to record part origins, but remain convinced that my final running B1 mechanism was on the driving wheelset - long before solidly repaired with Araldite - from my first Bachmann B1 mechanism. That wheelset went on to a regular correspondent on the old MREmag, and put in more use replacing a B1 wheelset which had cracked its muff and gear.

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  • 2 months later...

I am just dealing with my first split chassis maintenance issue and reading the thread I wondered the following. The white grease referred to above might well be Krytox which is a specialist high temperature lubricant. My Wraysbury Hall has a good quantity inside the body shell and as soon as the spares arrive I will be using some of the spare grease on the non driving wheels where the previous bushes have cracked, but on the driving wheels I'm reluctantly going to stick to Powerlube as Im not sure of the conductive properties of the aforementioned white grease. While using thin oils generally seems to be the recommendation for loco moving parts, these are going to be easily pushed out of the joints and I wondered if anyone had long term experience with very high viscosity greases instead?

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 Hi 313201,

Unfortunately this is a very common state of affairs when dealing with Bachmann engines with plastic inserts.. I do hope you carefully cut out the wheel weights and then glued them back into position. This does help to make the loss of the inserts less noticeable. I have done all my 4mt's this way. have not had a problem with my other Bachmann engines so far.

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