Jump to content
 

Bachmann/Mainline J72 Axle Replacement


hartleymartin
 Share

Recommended Posts

Hi Everyone. I have one each of a Mainline and Bachmann J72 both suffering the problem of split axles.

 

I have in my possession a set of replacement axles for both from Peters Spares, but I have no instructions as to how the replacement should be carried out. Any help, advice or previous experience in doing this repair? 

Link to post
Share on other sites

I presume you refer to the white nylon stub/isolating bearings, The centre one has the gear moulded to it.

 

1. With the chassis positioned upside down, strip down the chassis by removing the keeper plate. Lift out  the wheelsets and put the chassis to one side.

 

2. The wheels can now be separated revealing a square shaft.

 

3. The new bearings have a square hole but may need a bit of fettling  to slide onto the wheel stub axles. They should be a "push" fit, not sloppy or forced on. The latter will split the bearings (back where you started!). Too loose and the wheels won't stay in gauge. It is essential to ensure the wheels are set with the quartering at 90 degrees. For LNER locos it is right hand side leading. i.e. with the wheels on a flat surface, the right side cranks face forward, the left cranks should point upwards.

 

4. Back to the chassis, make sure the bearing surfaces are clean, likewise the stub axles. I use Servisol 10 switch cleaner, which is safe on motors and plastics. It will evaporate and leave a fine conductive film on the surfaces.

 

5.With the wheelsets complete drop them back into the chassis and replace the keeper plate.

 

All being well, your loco should be a happy runner once more.

 

I do hope that is helpful as I don't know how much knowledge and skills  you have, so I have kept it a straighforward procedure and should take less than an hour to achieve. Good luck with it and do let us know how it goes. If you need any more advice, come back on here or PM me.

 

Tod

Link to post
Share on other sites

  • RMweb Gold

4. Back to the chassis, make sure the bearing surfaces are clean, likewise the stub axles. I use Servisol 10 switch cleaner, which is safe on motors and plastics. It will evaporate and leave a fine conductive film on the surfaces.

 

Tod - Are there are any physical chain stores where you can go and buy the Servisol, or does it have to be an on-line purchase? It isn't a product I've heard of, but have exactly the same J72 issue. Even the new (for use but not by purchase date) spare chassis I bought ages ago had generated the same issue whilst in storage and still in the unopened packaging! Therefore I currently have 2 chassis needing the fix.

 

Not averse to buying on line but it is so often a faff to be having to wait in for the deliveries as unless it is the local R Mail letter-post the time slots are so random.

Edited by john new
Typos corrected
Link to post
Share on other sites

Hi John,

Squires in Bognor is where I usually get mine, but any of the modelling tool specialists are likely to sell it. It is in an aerosol tin, so there may be posting restrictions. Give them a call 01243 842424, email; sales@squirestools.com or www.squirestools.com

They attend many exhibitions around the country and if you look in the model press their advert shows where they will be trading. Good luck with your locos and Bachmann can supply replacement parts, in case you didn't know. They are very helpful, quick and good prices. Their number is 01455 245575. For my V1/3  Insulated axle centres and gear set was £3.00 plus £2 p&p.

Disclaimer:- No association to the above, just a happy customer.

 

Tod

  • Informative/Useful 1
Link to post
Share on other sites

you're welcome, happy to help. I suggest you contact Squires to ensure they have stock for you. They are most likely to have plenty of stock with them, but I'm sure you know the Law of S-d!

 

Tod

Edited by SweenyTod1
advice added
  • Agree 1
Link to post
Share on other sites

  • 2 weeks later...

I have some mainline J72 wheels and they don't have squares on the axle ends...  The wheels sipping on the axles seems to be the normal reason for scrapping Mainline locos.

Link to post
Share on other sites

Peter's Spares sell their own replacement axles for the round end style.  I have used them a number of times,

 

there is a trick to this although the quartering does not need to be 90 degrees it does need to be the same.

 

I apply loctite to one end of the axle and install the wheel and leave to set.

 

I separate the chassis and remove the motor and then put the chassis back together.  Repeat the loctite on the other end of the axles, install the wheels and align by eye and then put into the chassis and install the wheel keeper plate.  put the chassis on the track and gently push along the track, watch carefully for binding adjust the quartering on the wheel when it binds until the chassis can be pushed along with your little finger.  When it is correct you will be able to give the loco a gentle push and it runs freely along the track. do this in both directions.  When you are happy it is as smooth and free running as it can be leave overnight for the loctite to set.

 

Take it apart, reinstall the motor and reassemble the chassis.  Put the the wheels and everything back together and test run.

 

I have lost count how many times I have done this for customers, it also works on locos with pistons just have to put the piston rods into the pistons.  these older locos have push fit pins to hold the con rods in place I do not remove them unless I can punch the pin out from the back.  If you try from the front the pin often breaks off.

Link to post
Share on other sites

  • 2 weeks later...

I've also had this problem with the split axle J72s, both the early ones with pancake motors, where they by Palitoy and the later Bachmann ones with the in line motors. I look forward to the new ones due any minute now I hope they have metal axles.

 

The problem seems to arrise with other Bachmanns models using the split axles system. Here is the wheel set from their 0-6-0 USA switcher or shunter. The first of my pictures shows the splits in the front and rear axles which have also come loose. the centre geared axle seems to be OK and has remained solidly fixed.

 

P1010050a.JPG.b2a30ab5152a66d35739e3478fa9c689.JPG

 

What to glue them back together with? First I degreased them with lighter fuel and decided to superglue them back together and not use the weaker Granville Lockthread which is meant to stop your nuts dropping off vibrating engines, cars and old motorbikes.

I've got my home-made back to back gauge there to hold the wheel stubs in place as the glue sets. It's made from layers of balsa wood and cardboard and is set to match the fixed bear axle so it runs through my PECO code 75 check rails.

 

We'll see if this repair holds up under running conditions?

 

P1010052a.JPG.e0bafe6cff4e2918da3c3a30bff987ff.JPG

Edited by relaxinghobby
spelling
Link to post
Share on other sites

This problem seems to have the little people nearly as perplexed as me with how to fix the wheels.

So far it has been harder than ever I could imagine it could be. Gluing the metal wheel stubs back on using a home-made gauge block to keep them at the correct distance apart I found it was best to do one wheel at a time. Glue one in with super-glue and hours later or the next day fix the other end with Granville's Threadlock as it gives you more fiddling time. Super can set before you get everything into place and check which is not good, or not get a wheel at the right angle.

On the second pair I over did it with to much super-glue and squirted some down the central plastic tube section or the axle and had to drill and dig out the surplus with a sharpened screwdriver.

They now all roll through these code 75 points and I'll give it 24 hours for the glues to harden up and I can put them back in the chassis block and see how they run?


 

P1010064a1.JPG.be915c51b47ce507a4b1c72f0484abae.JPG

 

Cracks in nylon or white plastic still visible at 1 and 2.

 

 

 

Added a day later, now I've tried it out the news is not so good. The wheels turn but the running is wobbly may be that some replacements will be needed after all because without some sort of jig getting each wheel stub lined up correctly and attached to the centre axle tube was not as easy and accurate for me as I had hoped.

Edited by relaxinghobby
typo
Link to post
Share on other sites

  • 4 weeks later...

There's a chap 3D printing replacement gear and spacer sets now.  I'll try those as the material is different to Bachmann's brittle nylon.  Never-run split chassis locos can be had very cheap now; no worries about bearing plating wear with NOS examples but the spacers often crack after less than an hour's runtime - it's age, not use, that embrittles them.

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...