Problems with tender driven A4 LOCOS

[Gnome One]

i am currently working with a number of A4s which frankly have spent too long in my attics. A common problem is getting the tender driven locos to perform 'correctly' as what is happening is that the tender appears to be doing what it should but he loco itself remains steadfastly 'stuck' - no sign of life.

The result is that the tender has enough energy to push the loco forward but there is to repeat no response by the locomotive.

Welcome any help and advise you good people may have!

Bill Postgate

[What About The Bee]

Hello Gnome One

The torque created by the friction of the wheels against rail is insufficient to overcome the internal A4 friction. The internal A4 friction are axles to sleeves, valve gear & etc.

Clean and gently lubricate the A4. The wheels should be clean, as any bump on the wheels will prevent them from rolling, and thus no torque at all.

Bee

[ColinB]

I know the feeling, that is why I replaced or converted all my tender driven locos to loco driven. As someone said make sure everything is lubricated, I also had issues with the cylinder block where it had cracked and was not properly aligned with the valve gear.

[Going Spare]

Are the tenders pushing the locomotives forward but the locomotive wheels are not turning, just sliding along the rails? If so, check and lightly lubricate as necessary as Bee advises above, and also check that none of the motion rodding has got bent causing one rod to rub heavily or even jam against another as they move.

If the tender motors are running but not achieving any movement, check the condition of the traction tyres - two per tender in the wheels that have a groove cut in their tread - if they have a glazed surface or are no longer gripping the wheel, replace from packs X8030 if UK-made locos or X8439 if Chinese.

If the tyres are ok, for UK-made locos check the colour of the spur gear on the motor shaft. If a silvery alloy, it may no longer be gripping the motor shaft and should be replaced with the brass S2290 version. If the locos have been in storage for some time, light oiling of the motor shaft bearing immediately behind that gear will probably be beneficial (both UK and Chinese models).