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[littlejim]

overdrive.

O/D worked beautifully for the first few test runs, then spat the dummy.

When, eventually, the correct synapses connected, I topped up the gearbox (took a good pint) went for another run and put a few more ounces in.

All electrics up to the output side of the O/D solenoid work OK, but the 'pull in' lever at the side of the gearbox just sits there like Buddha.

Looks like the cutout/pull in side of the circuit at the gearbox has a problem.

 

Before I start pulling the inside of the car to bits to get at the top of the gearbox anything else to try?

All suggestions gratefully accepted. (Maybe not the rude ones.)

 

Postscript: at higher revs in higher gears get the equivalent of clutch slip, which I suspect is actually the O/D.

Edited September 23, 2010 by littlejim

[vivdownunder]

Hi Jim,

 

Not sure if I can nail the problem, but we'll have a crack. Forget the oil level for the moment and try this -

 

Engine off, car in top gear, ignition on - flick the O/D switch to on. Is there a sharp clunk as the solenoid drops in, or silence ?.

 

If it's silence, are you absolutely sure there's current to the solenoid ?. If there's current, then the solenoid has carked it.

 

If the solenoid attempts to drop in but can't, it will most likely be a swollen or wrong O ring on the cross shaft. This jambs it and overcomes the force of the solenoid.

 

Regarding the clutch, the 4A type can be a pig to adjust. Clutch slipping won't be the overdrive if it's not engaged.

 

Is the clutch return spring still there and operating correctly ?.

 

Reach under the car and grab the clutch shaft lever. Move it to the rear and there should be about 5mm of play before the clutch bearing hits the clutch.

 

If not, then it's likely to be pressure retention keeping the clutch engaged. That's usually master cylinder adjustment. The rear valve in the M/C has to fully release fluid back into the reservoir.

 

See how you go.

 

Best,

 

Viv.

[littlejim]

Our boy comes good again!

 

Thanks Viv, that gives me a bit to go on with tomorrow, none of which would I have thought of myself.

[Tr4Tony]

Jim

 

If you start getting progressively greater clutch slip at higher revs and the OD becomes difficult to engage or drops out, then its most likely that the clutch material in the OD unit itself is wearing out.

 

Regards

 

Tony

[littlejim]

Thanks Tony,

I'm hoping that's not the case, it has only done about 5 miles since I put it in.**

The gear box was non O/D and the box and O/D were done up and mated by gear box specialist, while I worked on the chassis and body.

 

** but, of course, stranger things have happened.

Edited September 23, 2010 by littlejim

[ChrisR-4A]

Hi Jim, ref the slip, was the overdrive unit fully reconditioned? If the slip is more of a slurr as the overdrive engages, mine can take a couple of seconds if actuated at over 65mph, but is instant at under 55 on a light throttle It's been like this for the last 10 years and I intend to leave it until I have to remove the gearbox or engine for something else. I checked with one of the overdrive specialists at the International and they said my O/D cone clutch was probably worn but could continue to work as it is for a long time as long as the slip did not bother me.

Chris