Troublesome Jinty/ J83 chassis

[Ken Shabby]

I recently bought a cheap J83 which was DDC fitted non runner. I had a spare motor with came from a 08 shunter chassis, which was around 20 years old and had the sprung rear wheels. As I don't use DCC , I swapped the motors which was a 2 minute job.
The problem is it's a terrible runner. The motor has been tested while removed from the chassis and runs fine. The chassis has been cleared and very lightly lubricated with some oil purchased from Gaugemaster also all the wheels are clean and the pick ups make good contact with the wheels.
So the chassis is very free running and the motor is working well, but put them together and it runs worse than my old Playcraft 0-4-0 diesel shunter.
Here's a couple of photos.

Any ideas ? All I can think of us maybe obe of the wheel sets has a intermittent fault and is not properly insulated.
Cheers Ken

[Bufferstop]

The rear part of the pick up in the top picture looks twisted. My suggestion would be take off the pick ups straighten them out and put in some tension to make them bear on the wheels. Then cover the back of both of them with thin sellotape, as there's the possibility of them touching the chassis block. You could try removing the two chokes and capacitor that are across the brushes, I've done it in the past and got an improvement in running, and not noticed any effect on TV or Radio reception.

[GeraldH]

I may have spotted the problem. I have been playing with these chassis for years . There are several different versions of these chassis which have evolved and improved over the years. The latest ones have fully flanged wheels and 6 wheel pickup. Earlier ones had flangeless traction tyred wheels on the centre drivers with a one sprung outer axle and four wheel pickup on the outer two axles. Your chassis is the latest revision with fully flanged wheels with no tyres. The motor that you have salvaged comes from the earlier revision and only has pickups on the outer four wheels. The centre wheels on your repaired loco are now effectively insulated and are intermittently lifting the outer wheels off the track while running. The solution is to add centre pickups. This can be done by soldering on some pickups which is what I have done, or putting the salvaged motor in the original cradle which has 6 pickups (also requires soldering).

[Bigmet]

Good leads suggested to check out, I'd add another, a 'dry' soldered joint in the circuit.

[Ken Shabby]

Hi everyone,
Thanks for the advice, due to working extra hours and the incredibly annoying loss of my glasses,
my fault finding of this loco hasn't progressed any further , but 'm hoping to have another look at it over the weekend.
Ken

[Ken Shabby]

She's a runner , adding extra pick ups to the centre wheels solved the problem.
The only problem is the body can't be refitted as the bottom plate of the chassis is damaged.
Both of the 2 pegs that fit through holes in the front of the loco body were sheared off by the previous owner. On the 80's era Hornby 0-6-0 locos this part was more flexible and robust , but the part fitted to the current 0-6-0 chassis (L.5698) is extremely brittle and you won't be surprised to hear it's been out of stock everywhere for quite sometime.

Ken

[Bigmet]

Any way of making a piece with the two pegs on it and gluing or screwing it on?

I take it these are the same two pegs that were cast into the rear of the chassis block, which located in two apertures in the rear of the bunker on the Jinty moulding? If so sawing this piece off an old worn out chassis casting would be one way to go.

[GeraldH]

I take it these are the same two pegs that were cast into the rear of the chassis block, which located in two apertures in the rear of the bunker on the Jinty moulding? If so sawing this piece off an old worn out chassis casting would be one way to go.

The new version of the pegs have to flex to get the body on and off and now usually located at the smokebox end rather than the bunker end. I'm pretty sure that they don't match the position of the cast ones on the earlier Triang chassis. I've had several of the new ones snap over the years and some just seem to be poorly moulded causing them to snap very quickly. Some years ago I wrote to Hornby and pointed out that these regularly broke and suggested that they made some spares. I actually received a very positive response and they did become available again, so it might be worth trying Hornby as these chassis must be almost constantly in production for the Railroad 08, J83, Jinty, E2/Thomas, J52 etc..