Humpty Dumpy

[Slooby]

Have you tried removing the brake shoes and getting to the back off the hub to heat in there which a bit of percussive accompaniment?

[cobbadog]

Hi Slooby, no not as yet. Picked up a hydraulic puller today and will attack it tomorrow. But it is an option to work towards if needed. Thanks for the reply mate

[cobbadog]

Well this morning I put the hydraulic puller on after removing the brake shoes. Well they had partly removed themselves because of a broken return spring on the shoes so I nee to find another spring. There was an issue undoing the brake adjuster from the backing plate due to a nut being rounded off then painted over but I won that battle too. Then with the new puller in place I started winding up the small threaded handle and I thought I heard a noise so I backed it off gave the hub a good hard knock to go back on but did not move. So now its time to get serious and put some fetch on this mongrel. I did refit the hub nut incase the lot wanted to go next door and through the fence. As I wound up the little handle it definitely went bang and the hub was against the hub nut and no signs of it being broken. Slipped it off and found that the oil seal is held in place with a sheet metal section and so I undid those 6 nuts and bolts and the seal is in my hand. Pulled the backing plate forward and found 3 shims behind it and the bearing. So I have these to wash up and get ready to put a sealant there as the oil has to pass these to get to the seal. (Pommy Engineering) There is a thin paper gasket between the seal holder and backing plate so I will make another one of them for assembly time. The area on the hub for the seal to run on is in excellent condition so wont need a speedy-sleeve. Brake shoes were spared any oil contamination as the oil ran down the backing plate then onto the tyre. So when in town next I will need to track down a spring to suit a 10" brake shoe and all will be well in the Universe again. On the adjuster one of the sleeves that moves in and out had seized and was why I could not back it off any more but that too is sorted. Winner!

[gecko.cx]

Good result!
The best I can say about that design - there is a reason we don't do it like that anymore!

[Slooby]

Hurrah!

You can bet the design can trace its way back to the 1920's when the seals were made from leather, but by the time they built yours rubber technology meant proper lip seals existed and they just made a seal to fit the existing space rather than do a complete re-tool. A bit like the BMW era at Land Rover where they decided rather than re-tool RV8 to metric, they would just get imperial bolts and nuts made with metric heads, and put some marking on them to inform the mechanics...

On the puller front; did you go for the hydraulic assist screw in type, or the full inverted bottle jack with a threaded body to accept the puller 'head'? I have a cheap version (30 quid off the Bay of E) of the latter and while cumbersome compared to the likes of the jewel like, and similarly expensive, Sykes units it has served me well thus far

[cobbadog]

Hi Slooby, I borrowed a assist screw in type. No sooner got a little bit of fetch by hand only on the short handle the hub came flying out only to be stopped by the hub nut. So happy it is off and now have the seal and spun metal holder on the ground.
Something I noticed and not real pleased about is once the oil seal was off I decided to remove the backing plate and the shims behind that to clean everything up. The Pommy design has an oil seal on the outside but none from the backing plate and shims so the oil leak may have been comming from that area as oil has to pass the shims n backing plate before it gets to the seal. So on assembly I will use some good old RR gasket sealant between all shims, diff housing and backing plate then the seal holder has a thin paper gasket which I will make a new one and seal it as well. Plan is to have it all back together and sealed up and then put it up for sale. We have had it since 2015 and have a lot of fun with it but I want to start moving things on and make more room for smaller toys. Still keeping our David Brown Cropmaster but selling the 8 ton Hino beavertail truck too. Some other stationary engines that I can no longer move about due to 2 bung shoulders so time for new owners.

[cobbadog]

New oil seal on order and will be here soon but now looking for the return brake spring.

[Janmik]

Hi, I took the drums off but my screws are damaged? Where can I buy new screws?
What is the disc label? I have one bad bike...

[cobbadog]

Is the thread on that one stripped? You might be able to find a wrecker that may help but I would repair that wheel stub by building it up with weld, machine it down and then thread it back to standard. If thread is damaged in the hub use a helicoil

[gecko.cx]

I think if the thread in the hub is damaged, I'd be more inclined to drill the thread out to suit a modern press-fit stud.