Hi
A very quick question, which I suspect has a very quick one word answer…..
In order to change the overdrive solenoid, do I need to drain the gearbox/overdrive oil ?
Am I likely to dump the entire contents on the driveway, or could I use the Dutch boy at the dyke routine and stick a bodily part in the hole !
Nothing I’ve read actually states to drain the oil first, but if I need to, I guess it’s a good excuse to remove the overdrive sump and clean the filters.
I would drain the oil and clean the filters anyway, being very careful not to loose valves and little ball bearings etc. You could do with a special tool to undo one of them...but like a 2 pronged fork. Do this and you may cure the problem anyway.
But if this has been done recently and you know its the solenoid it can safley be removed with the right spanner and no oil loss....but why did it go wrong?
Jonners
Note from Admin: sadly Jon passed away in February 2018 but his humour and wealth of knowledge will be fondly remembered by all. RIP Jonners.
The car has only done 1500 miles in the last 10 years, and was stood for the last seven until I got it in May.
So as you can imagine there were quite a few moving bits which didn’t…..
(It’s just had the original factory clutch replaced !)
The overdrive did work briefly, for about two miles – before starting to pulse and drop in and out, then died altogether.
My first thought was low gearbox oil – but that is now full and still no overdrive.
Electrics seem ok, I can just detect a very faint click from I guess the solenoid when flicking the switch.
I assumed the first port of call would be the solenoid on a car which has stood for so long, but if you think the filters would be a better bet – I’ll start there.
On a slightly different note, has anyone chopped a hole on the passenger side of the tunnel to make the gearbox filling easier – is it recommended ?
With oil that old it's probably a good idea to change it, it has probably gone thin from age and the overdrive needs lots of pressure to work properly.
I'm no expert on ODs but thinking through the parts of the system logically and how age and lack of use would affect them:
Oil: totally unknown area for me beyond checking the level. Probably worth a full change as Dave says. Moisture got in?
Clutch cones: never heard of them failing other than wearing out. It's obvious when they go as it's like clutch slip. The plates could stick or disintegrate but they aren't intermittent faults.
Filter: Can't think how age and lack of use would increase clogging to such an extreme degree.
Solenoid: Its a pretty solid lump of mostly copper, not a helluva lot to go wrong.
Valves and seals: Do wear out, stick and otherwise fail especially if moisture gets in or they are left drained.
Wiring: Fails through corrosion in connectors. Fails through corrosion in the wire. Fails through tarnishing of the wire. Fails through chafing. The switches fail. All likely to be intermittent.
Then apply Occam's Razor.
Check your wiring again. Twice. Run a temporary wire from the fuse box or battery clamp in through a window to any old switch then out again under the car to the solenoid. Run a link from the solenoid back to the battery negative too. Use over chunky wire and red/blue/yellow crimps and a good quality tool so you can be 120% sure the temporary wiring is good. This will bybass everything including the protection switches so remember to switch off when in first and especially reverse.
After that drain and check the valves, clean the filter and fill with fresh oil. Only after all that woild I think about changing a solenoid.
... Still Sprintless.