1987 JCB 3CX Syncro Shuttle Drive Problem

[Slooby]

Help!

If you've been following my Project thread my apologies for the repeat but, after nearly three weeks of fettling to tidy up the cab of my newly acquired machine, fix some leaks and rattly bits I finally got to the point where I could run it up with the plan to get the engine good and warm before doing an oil change. Well, that was the plan, it didn't want to move from the spot where I'd parked it about a week ago.

The only fiddling I have done with the transmission has been to change the output shaft oil seal, the transmission filter and top off with 3.5 litres of fluid that had been lost (2 litres) during the seal change and wasn't in there to start with (1.5 litres). I had moved the steering column shroud during my cab tidy and been wiggling the cables encased within. The shuttle lever and indicator/lights/wiper stalk are a bit loose on the steering column, and since the fiddle I appear to have lost indicators and wipers, I don't think the horn or washer buttons did anything before and they certainly don't now.

These are my drive controls arrangeement:



In addition to fiddling with the steering colum shroud I have also had the front load controls in pieces, but I didn't overly stretch or disconnect the main control lever with the transmission dump switch.

Before I go tearing into the electrics, is there anything obvious I could have missed with the way the machine is meant to operate? I did notice after a little bit of running the 'charge' light illuminated, so could a poor charging circuit or weak battery cause the shuttle or transmission dump system to wig out?

[Jeremy Rowland]

Tim, this sounds like a loose or bad connection on one or more of your wires; I'd remove the steering column shroud and wiggle the wires to see if you get the indicators and wipers back, let us know how you get on.

Jeremy

[Slooby]

Thanks Jeremy, that's going to be the plan. First job is going to be getting the steering wheel off, where the central boss has been glued on...so this should be fun!

I'll take pics as I go and work my way down from the cab to underneath tracing everything through...

[Slooby]

What a mess!



Next job is going in there with a brush and the hoover to clean up

The Shuttle lever main connector seems intact and fine along with the wires to it, however the separate flying lead (which I presume is for the horn) is spliced off the heater blower switch and back to the loom with Lucar type connectors, which I detest, and will warrant checking then replacing when I get my decent soldering iron back with proper lead solder and not indium. I found one black wire off one of the switches with the insulation fretted away, so that will need addressing. I really don't like using electrical tape for such jobs as it has a habit of coming unstuck and falling off, self amalgamating loom tape is ok,unless it comes into contact with another piece somewhere else and then they bond to each other and things get messy, decent adhesive lined heatshrink is my preference...if you can get it over the connector :/

Anyhoo, found these two flying leads near the fuse box, one coming off it (blue with a red stripe) with a male spade connector, and the other coming off the loom (blue with a white stripe) and a female spade connector, not sure what they were for so will have a look at the wiring diagrams.



All the fuses are intact

Further down on the same side as the fuse box I found this heavy gauge connector with lots of copper corrosion, so that needs a clean up



And I also now know why the levers/stalks are spinning on the steering column:



Will be fixing that by drilling out, taping a thread and thread-locking in a suitable piece of studding

Annoyingly no smoking gun on initial inspection, so it might be one of the transmission dump switches

[Slooby]

Well it seems that the spliced in wires from the shuttle lever button have been connected to the windscreen washer pump, rather than the horn that it should be connected to

[Slooby]

Well I've pretty much completed my cleaning off of the loom and bulkhead (paintbrush, old toothbrush, hoover and a cloth), I've tidied up the loom as best I can and cable tied things into some semblance of order but nothing relating to the shuttle lever or the pedal transmission dump is leaping out at me as being obviously suspect.

I'm told that we have a multimeter here somewhere, so tomorrow I guess I'm going to be buzzing wires through for continuity. I've printed off a copy of the wiring diagram and key for my generation of machine to help me in that regard.

I fear though that this is going to be a rather long and drawn out process to find the issue

[Slooby]

Most of yesterday was speant working my way through every connector and wire on the loom that lives behind the steering column shroud, having discovered that it was fairly easy to disconnect and remove that section from the cab I did so and sat down with it at a desk.

I solemnly disconnected every spade terminal from each relay/control unit and using some fine sand paper removed all the corrosion I could, until eventaully comming to the ignition switch master relay, where I may, jusy may, have found something:



The terminals for these two wires (and relay in the background) were quite heavily corroded, and the female spade connector on the Green and Red stripe wire was also missing its 'tongue' (compare it with the one on the black ground wire above). That wire is the power feed to the Shuttle control lever. That relay is also one that I dislodged and forgot to reattach to the steering column shroud when I previously moved it to clean the detritus out of the heater vent and it was banging around against the cab bulkhead.

I'm wondering if a combination of the corrosion, lack of a complete contact between the wire and relay and a weak battery, was just enough for the Shuttle selector mechanism not to be able to switch the solenoid actuators on the gearbox?

Re-fitting of the loom and testing is about to commence, fingers crossed then...

[Slooby]

Well all of that work on the loom did absolutely nothing to improve things other than get the lights, indictors and hazard warning lights working again, still no drive...

That 5 gallons of petrol my dad just bought is looking mighty tempting right now

[Jeremy Rowland]

Well all of that work on the loom did absolutely nothing to improve things other than get the lights, indictors and hazard warning lights working again, still no drive...

That 5 gallons of petrol my dad just bought is looking mighty tempting right now

It's rather infuriating when you spend lots of time and effort only to find that you still have the initial problem; I am no electrical expert so I cannot offer you any advice.

Jeremy

[essexpete]

Does this machine have a transmission, disconnect when the handbrake is applied?