The main A1/A3/A4 Chassis & Bogie problems & fixes

[Peachy]

Hello gang, I’ve trawled through a lot of the good, bad and ugly threads regarding the various minor issues that customers have found with some of the Hornby TT120 A1/3/4 Pacific chassis and hopefully covered all of them here in my latest YouTube video.

I think I’ve caught the main issues, but please add forum thread links to anything I might have missed.

I’ve mainly focused on bogie de-railment of course, but here’s what’s on the video;

1.      The Black tape.

2.      The spring issues.

3.      Wheel gauge/spacing.

4.      Body detail fouling.

5.      Mech/loco handling issues.

6.      Grinding motor/gears.

[Peachy]

Or you can read these;

front bogies william whitelaw :: Hornby Hobbies

Night hawk :: Hornby Hobbies

TT120 Flying Scotsman bogies :: Hornby Hobbies

A4 lifting front wheels on curves :: Hornby Hobbies

Front Bogie Lifting/De-Railing :: Hornby Hobbies

Black Tape and Shorting. :: Hornby Hobbies

William Whitelaw A4 rubbish on R2 curves :: Hornby Hobbies

No right turn :: Hornby Hobbies

Flying Scotsman tender drawbar fastening screw fell out :: Hornby Hobbies

And there's a lot more from where they came from! grinning

[Fishmanoz]

On derailing, and given your second link includes my post linking back to your first link, which in turn links to other earlier relevant topics, I think you have it covered.

Next you could summarise Mk 1 and (lit) Pullman running problems?

[Rallymatt]

Good work Peachy 👍

[Peachy]

On derailing, and given your second link includes my post linking back to your first link, which in turn links to other earlier relevant topics, I think you have it covered.

🤣👌

Next you could summarise Mk 1 and (lit) Pullman running problems?

I did think about them, but I’ve got a feeling Hornby have actually got to grips with them haven’t they?

 

 

 

 

[Peachy]

Good work Peachy 👍

 

 

Cheers!

[Peachy]

Thought I’d try reverse psychology on the MODs 🫢😉

[RB51]

Forward- or reverse psychology- not required. Good piece of information. R-

[Peachy]

Forward- or reverse psychology- not required. Good piece of information. R-

 

 

😝

Cheers Roger… I was just having a bit of fun.

[David-370477]

Hi Everyone,

My first post on the forum which is a response to very informative Peachy post on "The main A1/A3/A4 Chassis & Bogie problems & fixes.

A few months ago I purchased a A3 CLASS 60078 'NIGHT HAWK' BR EARLY GREEN (DCC-SOUND) locomotive. I thought that the bogie wheel lifting and derailing issues raised by others much earlier this year would have been sorted out by now but not a bit of it. Out of the box, when the locomotive was traversing a radius 2, and, albeit to a lesser extent radius 3 curves the two bogie wheels on the inside of the curve were lifting and often after just a few minutes running all four bogie wheels would derail leading a short time later to the derailment of the whole loco.

I removed the infamous piece of black tape adhering to the underside of the loco above the bogie wheels but even before I removed it was clearly not interfering with the bogie wheels movement. In short, removal of the black tape made not a jot of a difference.

I checked that the bogie was bracket was not out of alignment with the locomotive and that the bogie wheel spacing was correct and all was good.

I finally came to the view that the downward pressure of the bogie on the track was inadequate. I liaised with Hornby and they sent me details of how I could return the locomotive to them, whereupon they would "adjust the bogie bracket". Given that they advised that I should allow 28 days for the repair, I decided to have a go at rectifying the problem myself.

To cut a long story short (apologies for this), I carried out a very crude modification to the bogie as illustrated in the attached photo.

Firstly, I fashioned a 1mm thick washer from a piece of green plastic sheet and refitted the bogie to the loco (leaving the existing thin plastic washer in place). This lowered the bogie such that the spring was now under more tension. I saw a marked improvement by this mod alone but there was still a small amount of bogie wheel lifting on the curves.

My second mod involved introducing a small loop of 1mm thick solder between the washer sitting on top of the spring and the the underside of the bracket in order to increase the spring pressure. I only used solder in order to allow me to quickly try out the mod without having to avoid disassembling the bogie.

These two small mods have eliminated my bogie wheel lifting and derailing issues. In due course I will replace the homemade washer and solder loop with proper washers but for now I am just pleased to have a locomotive that runs properly. I hope these suggested mods may be of help to others.

[atom3624]

Incorrect post.

Edited February 19 by atom3624

[Fishmanoz]

New one on bogie modification and correct alignment etc: 

 

[Fishmanoz]

And another discussion:

 

[RB51]

The b2b adjustment has certainly quietened down traversing points. However the inner wheels of the bogie are still lifting on curved track. Time for the @David-370477 washer treatment. R-