1988 Jcb 3cx Alternator/Tachometer

[essexpete]

I changed the oil cooler on our old Sanderson teleporter from an integral water cooled to an external air-cooled because of leaks.

[Sailor57]

Hi Agrimax, thank you for your reply, what I thought was just a fat return cooling pipe to the bottom of the radiator is indeed exactly what you've shown in your photo. Next confusion is the drain plug you mention located above the bell housing grommet. I thought I'd drained and replaced the transmission fluid via the drain plug and sump strainer. Is there something else to change? The transmission dip stick now shows lovely smelling translucent 10w oil ( special Jcb transmission fluid)

I still haven't sorted the tachometer, it seems many owners just live with this!? Any ideas/clues would be welcome.

Thank you so much for your time, I notice you answer many other people's posts too which is very helpful and kind. Best regards, Garry

[Sailor57]

Thank you #11 for your good idea, was it an expensive mod? It would definitely be worth considering if the matrix is leaking. Best regards Garry

[Sailor57]

Hi Agrimax, forget my last query regarding the torque converter drain off, I've just read some other posts and now realise that a quantity of transmission oil remains in the torque converter, as you say, accessed via the bell housing grommet. I will drain that next time along with the other drain points, that is, after I'm certain the oil cooler isn't leaking. Best regards, Garry

[Sailor57]

Just a thought, looking at my oil cooler, which is the integrated version, I'm wondering if it should be called an oil warmer? After all it will warm the oil up to engine hot water return temperature which I guess would be around 70 degress? I'm also wondering if that's the case would the oil temperature fluctuate more if it had it's own seperate oil cooler. In other words have Jcb deliberately designed the transmission to work with warm oil ? Garry

[Rothers]

Hi, I currently have the same issue with the tachometer on my 1989 grey cab 3CX. As suggested the 'W' connection/post on the alternator is where the tachometer wire should be connected and you could test the output from this with a voltmeter just to make sure there is an output.

If not, I have been told it is quite common for the connection between the internals of the alternator and this 'W' post/connection to fail so it may just require re-soldering.

Good luck, and please keep me posted as I am keen to repair my tachometer.

Thanks.