Removing Sprocket from Excavator Hub

[DrWazzock]

This sprocket comprises a ring welded on to the hub. What's the usual method of replacing the sprocket?

Turn the weld off in a lathe or with a cutting tool in situ?

Can they be welded on in situ, which seems a bit brutal heatwise, or do I need to dismantle hub?

Anybody seen it done?

The spare sprockets are a reasonable price but the job doesn't look trivial to me.



Thanks.

 

[Kevtherev]

Going to have to be pulled off I’m afraid.
Big pullers and you will have to dismantle hub by the looks

 

[Kevtherev]

There’s a firm up in lancs that will re weld new sprocket rims on
Dave Jones track repairs.

 

[DrWazzock]

Gearbox fixing bolts torque 1000 lbf ft. I am going to need my Weetabix!

 

[davedb]

I’ve Re ringed then like this but that looks a bit more of a problem what is it on?

 

[Kevtherev]

Looks jcb to me???

 

[DrWazzock]

Yes it's a JCB 806 circa 1978. I was going to fit a new set of tracks which isn't such a problem but the sprockets look more of a challenge.

I wondered about fitting a lathe tool up next to the sprocket in situ, turn the sprocket using the hydraulic motor, and peel the weld out.

I had also wondered about then welding the new sprockets on in situ without dismantling the hub. Do a small run at a time to avoid overheating the internals. Bit concerned about the oil vapour exploding though there could be ways of preventing that.

Anyway, just mulling it over and trying to work out the best way forward.

I think that pulling the hub and pressing it back together is beyond my capabilities and equipment. If I could get the hub off I know a bloke with a lathe who could turn the weld out.

 

[Kevtherev]

I doubt you’ll cook something welding it in situ

 

[roscoe erf]

rebuild the teeth with the welder not done it myself but know some that have

 

[Cjm]

Looks like an arse of a job, but I imagine it’s possible to grind the weld out, and pull the old sprocket off even if you have to cut it into segments. Looks like the new one will locate neatly over the hub to centralise it then weld it back on. Don’t think you’ll cook it, just take the filler/drain plug out so you don’t over pressurise it when the oil warms up. Simples!
2 minutes to type, slightly longer to do....

 

[DrWazzock]

Thanks. The "in situ" route would certainly save some bother dismantling the hub.

 

[davedb]

I think with some careful welding you’d get away with doing it in situ as long as you don’t get it too hot and take the oil bung out to stop any pressure buildup

I’d just cut the old one of with the gas it doesn’t need to be perfect they only turn slowly so some slight misalignment won’t be a big deal

 

[Ley253]

Cant recommend the in situ idea, be very hard to get a good penetration with the welder, and to mount a trammelling or turning tool firmly enough would probably be as complicated as removing the sprocket. The tightness should be no problem, buy or hire a suitable torque multiplier.

 

[tomlad]

I would have thought steve woods track stuff , wigan , would sort u out
They'd know either way
Google eh ,

 

[Ukjay]

I would have thought steve woods track stuff , wigan , would sort u out
They'd know either way
Google eh ,

I would highly recommend them - he sent two lads down to me short notice to get me out of trouble with a stuck excavator.

They drove down and repaired my excavator track / ram when it came off.
It came off again and they took the ram away - found spring snapped - repaired, drove back down - refitted track, all for a very reasonable cost.

Noone local could be arsed!

 

[tomlad]

Plant mates use ,known steve prob 40 year
Big building now i believe , ive never visited .

 

[DrWazzock]

Thanks for all the good suggestions.

Frank Medforth used to do this kind of work round here but now sadly passed away.

 

[stev]

Try fenland tractors near crowland they have lots of big tracked machines in their yard so should be able to help some how !

 

[Sausage]

Doesn’t look too bad to me, remove cover, remove planetaries, undo thrust bearing pre load nut (admittedly may need to make special tool). Remove outer gear and hub. Probably sounds easier in my head than in practice, also that isometric isn’t exactly an engineering drawing.

 

[Shovelhands]

Weld the new rim on in situ. I’ve done it on similar hubs, it’s not that bad.