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Discussion Starter · #1 ·
After reading a recent thread on the Aster Pannier, I decided to run mine after some years on the shelf.

I carefully lubricated all moving parts and checked that everything ran freely with the engine upside down. All seemed OK, so I fired her up. So far so good. After clearing the cylinders, she seemed ready to run and off she went only to freeze a few yards down the track with the wheels locked solid.

I backed her up which freed the wheels and off she went again only to lockup again.

I've now spent hours trying to diagnose the problem but with no success. I've found that she runs fine with no weight on the wheels which points to a suspension related problem. I also suspect that the right hand side crank for the valve mechanism may be the culprit but can't see why.

Just wondering whether anyone has experienced anything similar with the Aster Pannier.

This image was taken of the underside of the machine with the wheels locked.
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Robert
 

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I know nothing about this locomotive, but would like to ask ??. Looking at the pic, the upper left wheel, just past the first eccentric rod, is that a crack? Don't think that is the cause, just wondering. You know the loco and how it runs, what makes you suspect the right valve crank?
Many times just a feeling leads to the conclusion. thank you.
 

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I don't know anything about this model but didn't this engine have a problem with crankshafts? Can't remember if it was breaking in the centre or slipping if it was a press fit assembly, this may explain the strange nature of the symptoms. I see replacement aftermarket crank shafts were once advertised in the UK. Mind you It may well be something simple but something to check.
 

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Some of the Aster Panniers had issues with the crank axle coming apart. The last runs of the model had the crank axle throws pinned, but even those will waller out. Just the Ticket in the UK sells replacement crank axles that are ready to install and do not suffer the same issues as the fabricated Aster crank axle.
 

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Take the coupling rods off both sides then turn the wheels by pushing on the track. This should prove if it is the crank axle quartering that has slipped. If it still binds then look for another answer. Also check for any movement of the outer ends of the crank axle, the wheels moving but the crank staying still.
 

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Take the middle crank pin out, so that the center axle is nolonger connected to the outer pair, see if the wheels move by hand, if they do, the crank axle is probably coming apart
 

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Discussion Starter · #8 ·
Take the middle crank pin out, so that the center axle is nolonger connected to the outer pair, see if the wheels move by hand, if they do, the crank axle is probably coming apart
Thanks for the ideas on how to diagnose this. I did remove the rods and the problem is definitely restricted to the center (driven) wheels. There doesn't look to be any play and the cranks are at 90 degrees. The curious thing is that the wheels rotate freely by hand with the engine upside down and don't lock but if you put weight on the wheels the lockup occurs after two or three rotations. When locked up, the wheels are pushed down hard on the suspension. Freeing the lock involves rotating the wheels in the opposite direction which moves the slip eccentric to the opposite pin.

I ordered a new crank assembly as suggested above as it seems like it is a good idea to replace it anyway. In the meantime, I will start to disassemble the cranks etc.

Robert
 

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Discussion Starter · #9 ·
I disassembled the running gear and removed the crank for inspection. It seems fine - rigid with 90 degree offset. I couldn't see any major issues so lubricated everything carefully and put it back together. The only possible issue was that the right hand driving wheel was not pushed fully into the crank:this resulted in some side to side play that could have caused the eccentrics to jam.

In any event, having put it back together, the lockup has disappeared. Always a bit frustrating when this happens as you can never be sure that you really fixed the problem.

Robert
 
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