JCB 3cIII gear box Help

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Real name: Tim
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JCB 3cIII gear box Help

Post #1 by Tim_tregear » Mon Nov 27, 2017 1:48 pm

Hi All, just registered with this site as there seems to be some really knowledgable people on here and I am struggling to find any info on a google search.

I have recently purchased an old 3cIII late 70's i guess. It is the model with the torque converter. When I select fwd or reverse it takes a fair while for the gear to engage, then once engaged it will sometimes drop out of gear once it has started moving. I am guessing this is due to oil pressure or lack of oil. Can any one guide me on how this system actually works, is it a seperate hydraulic system for the drive? and if so where is the fill. I have a pipe that connects to the gear box that comes up in the cab floor. Like I say I have tried to download manuals etc but can find very little. Any help would be greatly appreciated.

Thanks , Tim

Jeremy Rowland
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Re: JCB 3cIII gear box Help

Post #2 by Jeremy Rowland » Mon Nov 27, 2017 2:48 pm

Hi Tim and welcome :wave: there should be somebody on here who can offer you advice; it does sound like you have an oil shortage in the transmission perhaps the torque converter and the gearbox?


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Re: JCB 3cIII gear box Help

Post #3 by philwheelton » Tue Nov 28, 2017 12:37 am

Hi Tim you have a 3c mk2 with a Brockhouse 11N torque converter forward reverse unit , when you put them into drive they take a couple of seconds to take up the drive , this is built in to them , does the drive in the gear box jump out or does the f/r unit loose drive ?
the oil filler is in the floor , the dip stick is in the plate across the front and it needs dipping with the engine running, the system is a stand alone unit the pump is part of the steering pump on the right hand side of the engine just above the chassis , it should run on ATF fluid , hope this is of help to you . Phil

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