Cleaning a RG4 gearbox

[hayfield]

I have just bought a loco with a RG4 gearbox, its struggling to move and on inspection the gears are very stiff.

 

I have taken the motor off the gearbox, it works OK and its the gears are very stiff

 

At the moment they are in some white spirit, but it does not seem to be doing anything, the box itself is riveted together so I cant take it apart to clean everything by hand. In the past a squirt of WD40 seems to free everything up, but many warn against using this product

 

Any ideas please

[Tony Cane]

White spirit should do the trick, but also use a stiff paint brush to push the hardend grease out of the teeth of the gears.

[DLT]

10 minutes ago, Tony Cane said:

White spirit should do the trick, but also use a stiff paint brush to push the hardend grease out of the teeth of the gears.

 

And leave it to soak for a bit.  The lubricant in the RG4 gearbox goes hard after a period.

[Denbridge]

In the past I've soaked them in a good dose of WD40. 

[hayfield]

Thanks all of you, just had a look after 4 hours and its a lot freer, I will give it a bit longer, I may even give it a go in the ultrasonic bath

[decauville1126]

Having has several in the same situation I've found that removing the motor then submersing the gearbox completely in isopropanol freed it all up after about an hour. Several spins then a redunk followed by air drying, then a light oiling with TriFlow and they are all as good as new.

[hayfield]

Nice and free now, will let it dry overnight then give it a light oil

 

Thank you everyone for the assistance

[JeffP]

Another good solvent is Wickes paintbrush cleaner, the blue stuff.

Works quickly, excellent degreaser, washes away in hot water and then you re-oil.

[ikcdab]

What's the issue with WD40? I am use it a lot for cleaning.

I also use GT85 as well.

Am I killing my stuff?

Ian

[Roger Sunderland]

GT85 is excellent and not the same as WD40. It’s recommended on here for just such a task as oiling Portescaps by many, including me.

[Denbridge]

25 minutes ago, Roger Sunderland said:

GT85 is excellent and not the same as WD40. It’s recommended on here for just such a task as oiling Portescaps by many, including me.

I use GT85 for lubrication, but to free up the horrid grease in long static portescaps I find WD40 does the job admirably.

[Michael Edge]

GT85 gets the hardened grease out of Portescap gearboxes easily enough and as far as I know so far it doesn't damage anything. On the other hand WD40 has a terrible (and long term) effect on plastics. I've had a few Portescaps here which were completely solid, couldn't be moved at all by hand and some of them still had the leaflet with them which solemnly stated that removing the special grease would invalidate the guarantee......

[ScRSG]

Yesterday I chose to run a Portescap powered loco for the first time in a long time, and it started to screech very loudly! I managed to release the motor and its mount, luckily I was able to reach both the screws on the gearbox, and proved that the gears in the box were smooth as silk, but the motor itself!!!! The screech suggested dry bearings in the motor but even after very carefully oiling the front bearing only a very slight improvement was heard and even after a good hour of running no further improvement was heard. 

 

Has anyone any further suggestion or is the motor a write off? Has anyone fitted an alternative motor, coreless or not, to a Kean/Portescap gearbox? If so, any suggestions of make/type that fits 10mm mounting holes, 1.5mm shaft?

 

Thanks,

 

Chas

[Izzy]

Generally with the design of coreless motors there are two internal bearings rather than just the one long one, although it does vary. My guess would be the second bearing is still dry, so hold the motor vertically while running it - shaft upwards - and let the oil run down and hopefully it will reach it.