J Type wiring

[Peter Douglas W]

My O/D has been playing about.
Stage 1 Erverything OK
Stage 2 O/D dropping out at some time.
Stage 3 O/D dropping out when the engine/G/B gets warm
Stage $ Has completely stopped. No clicking noise from the solonoid.

According to God (Mike Papworth) it is electrical.
I put the car up on the ramp saw the access was terrible so I put it strait back on the ground.
I have measured the switch in the gear lever. The black lead has 12 V continuosly independent of the gear leaver position. The switch is OK. I can not hear a solonoid click.
Question before I do any more where does this 12 V come from? A fuse, a O/D switch, the reversing lighzt switch or what?
This will help me when I get under the car. I do not have any info about the wiring on this car. Perhaps it is original or perhaps not.

[Alec]

Hello Peter,

very often, due to gearlever movement, one one of the switch wires breaks where it exits the gearlever. That's the first place I'd look.

Alec

[Peter Douglas W]

Alex
great I have heard about this in the past but how do I measure this without dropping the G/B down?

[johnnydog]

Peter,
Last time my overdrive packed up (albeit an 'A' type), the problem lay in the two bullet connectors from the solenoid, which were crusty from exposure to the elements as they are under the car.The wiring is different on an J type, as the bullet connectors are inside the transmission tunnel just below the gear lever and aren't exposed. I agree, most problems are electrical, and if it has broken where it passes through the hole in the gearlever, a replacement piece from the switch to the bullet connectors is available cheaply from most suppliers. I tried making one up myself, but the main problem was getting connectors small enough to fit to the underside of the switch, and the effort finding these plus getting bullet connectors of the right diameter just wasn't worth the hassle.
These wires go to the reversing light switch on top of the gearbox - occasionally they can come off, but its easier to check them if the rear of the gearboxe is lowered slightly to gain better access.
I'd also check the two bullet connectors on the nearside of the bulkhead near to the fuel pump.
Whilst you are under the car, it's worth checking the oil level in the gearbox. If it is low this results in very lazy or no engagement at all. It also causes the overdrive to slip in and out of engagement when operated.

[Peter Douglas W]

This problem has been around since the Scotland National. Oil has been checked. I have reserve cables from Rimmers but the horror is dropping th G/B down. Therefore I am hoping there is some way of doing it without dropping the G/B. I know the A type vewry well and over the years I have had it out and back several times both in my six and my MK1.

[johnnydog]

It doesn't need dropping down much, just the length of the threads of the cross member studs, sufficient to get your hand above the gearbox to the switch. You don't need to even support the back of the gearbox, but just undo the four nuts sufficiently keeping the full depth of the nut on the threads for safety. You may have to undo the front exhaust clamp by the gearbox to avoid straining the exhaust. It can be done by putting the rear wheels on ramps.

[Peter Douglas W]

That sounds good. I hate taking the G/B off or dropping it down. Or even worse taking the O/D off on your own.

[Phil T]

Referring to post #2, lift the trim panel around the gearlever and check the wire in there.

This is where mine went - much easier to fix than crawling under the car so I would try that first.

[Peter Douglas W]

I took the trim panel off but I could not see the end of the cable only painted metal.

[Charles H]

The wires should come out of the hollow gear lever 2/3rds of the way down the lever. Remove the gear lever surround, the black vinyl on the surface of the console, and look there. You will be able to trace them easily to where they then disappear through the grommet in the tunnel. This is as mentioned before, where they tend to fracture due to the levers constant movement. You may have to pull out some sound deadening if any has been fitted under the vinyl.