What Are The Features Of A JCB 3C MkIII?

[mikefoxo]

Some day I hope to get myself a JCB (hopefully). Failing to get a 3CX 4WD I think I would go for a 3C MkIII What features does this model have though? 4in1 bucket? Extend-a-dig? Torque converter (by the way what is a torque converter exactly)? Forward-reverse shuttle? Any information would be much apprecited!!

[agrimax]

Like the mk 11 the 4 in 1(6 in 1?) was optional and I would say the standard bucket was much more common.Extending dippers are very scarce too.The torque converter models were known as Powertrain and had the foward reverse shuttle,ie no clutch. Basically a semi automatic.Just like a car only you manually changed gear rather than it going up or down itself.Then there was the manual 3x3 gearbox model.2 gear sticks,3 gears and reverse on one, and 3 ranges--H,M and L on the other. Standard clutch pedal on these.Prone to sticking in gear too.Had one.Nearly always jammed going down a gear going up a hill. Oh and don't forget you won't find 4 wd in the 3Cs.
Apart from the torque transmission,there really aren't many similarities between the 3C 111 and 3CX other than the early X having the same BMC engine for 2 yrs before Perkins went in.A heavy,clumsy beast too but they could certainly dig for their keep.

[XS650]

Spotted one in a film recently good views of the extendadig-

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[essexpete]

If you want a 111 then the Power train build 5 is the best by far. They are clumsy compared with 3cx but tough old things if you can find a tidy one . Cabs prone to rot out, particularly around the bottom. With the 4in1 and rare extenda they are very heavy beasts. The early pre Powertrain was also available with an older style torq con. The Torq convertor is a fluid driven transmission with no physical connection between the engine input and output to the reverser and gearbox. Google for working diagrams. The older t/c model was naturally quite slow engaging forward to reverse and I understand it was not easy to remove and service as it was part of an integral tractor skid.

[agrimax]

Just out of curiosity ep,was the old type TC available in the MK 111 or did it cease in the MK 11s?

[philwheelton]

I think the brockhouse 11N was fitted in the early MK111s the manual M/C had the 3X3 box ,then it went to the power train set up,they were good until they ran low on oil or the dump valve went out of adjustment .Just a good job they were easy to remove and repair.

[essexpete]

Yes I used a T reg (1978?) Mk 111 that had the Brockhouse. It would really push but changing gear on the move was tricky but not impossible and as I mentioned the delay fwd to rev was a pain. No dump pedal either. The latter was something that a former JCB fitter told me was a problem in the early Powertrain days as operators used to a clutch would attempt to feather the pedal.

[TullyveeryClassicJCB]

The Mk3's had just about every form of transmission including the old 10 speed manual gearbox as well before the 3x3 came in. My Powertrain is still immobile at the moment but how would feathering the dump pedal in the same way as feathering a clutch be a bad thing?

[agrimax]

William,Feathering will burn out the wet clutch packs quickly.Think the packs are meant to be fully engaged or disengaged only.Feathering would suggest that less than full oil pressure is being applied,allowing slippage.I suppose if you think about it,it's no different to a dry clutch.Feathering it is just causing it to slip too.

[TullyveeryClassicJCB]

I always feather the clutch when loading and unloading which is basically all the diggers are used for. I think Im going to find it very strange going from a manual digger to a torque digger.