1967 420 auto inhibitor switch

[DenisK]

Just bought the 420 with Borg Warner model 8 auto gearbox, inhibitor switch is faulty and unable to source a replacement, tried all the usual suspects: Manners, Barrett, about 8 others and trawled Beaulieu yesterday, with no success. Lucas part no was 34822.[img][img][img][/img][/img][/img] Anyone know of a 420 being broken or any other suggestions would be most welcome. Denis, Waterlooville, Hampshire.
UPDATE 10 Sep 2015:
Pretty well exhausted all avenues to find a gearbox inhibitor switch C23291(Lucas 34822) but have located a C22948 (Lucas 34774), said to be from an S type. It looks similar but with a different lever arm. I am wondering if the switch part would be compatible and whether I could replace the lever arm from my old switch?? Any ideas??

[Martec]

How about trying a specialist auto gearbox reconditioner? I can't give a name as I only have manual boxes.

Brian

[DenisK]

Thanks Brian, been down that route, think my best plan now is to try and find any 420's being broken for spares. Rgds, Denis

[piman]

Hello Denis,

I would try and dismantle the switch in the first instance to see if it can be repaired (I'm aware that it is probably not designed to be dismantled) and or investigate the option of using a different switch?

Alec

[DenisK]

Hi Alec, thanks for reply. Unfortunately the previous owner had the switch dismantled and a bypass wired up. Adapting a similar switch may be an option if I can find an expert auto spark as this would be a bit beyond my skills. There are other switches available (for the previous Borg Warner 35 box but they are activated by a button rather than a lever. Plan A is now to find a 420 being broken and plan B to adapt a similar switch. Regards, Denis

[piman]

Hello Denis,

never having owned an automatic, I am not familiar with inhibitor switches, but if it is only to ensure the selector lever is in Park before you can start the engine, a simple normally open single pole switch is all that is needed, and the two connectors are connected either way, so you can't go wrong?

Alec

[markcollins]

hi any one who might be still interested in this topic. having swapped my inhibitor switch for faulty but not broken one
I stripped the old one. carefully bend back the tags and apart it comes. full of dust etc. cleaned off all the copper runs with WD40 and
a blunt screwdriver.checked with a meter on rotation for continuity of reverse light and no start. yipie found it.on the rotor to go on contacts etc there are 2 spring loaded balls. very very gently use extra fine wet and dry rotate the balls and repeat many times.eventually they come clean and will conduct as required.also crap design the rotor relies on a s**t rivet to pivot on, on the base plate (which is very flimsy)
so i used a scrap piece of panel thick metal between bottom of rotor and base then re-peaned the rivet gently. low and behold it pulled it all tight and the BALLS now make contact when they should. good luck its worth a try.

[alec2824]

So you think a part that was made in 1967 and has now failed is a poor design! How long would you suggest the designers plan for? Alec G.

[piman]

Hello Mark,

Lucas industries is much maligned but unfairly I feel. Remember that the customer, i.e. Jaguar in this instance, buy on price (William Lyons was quite sharp in this aspect so he could sell his cars at an attractive price). The supplier would have a specification and produce an item that fulfills that and at a low cost. Don't just blame poor engineering or design.

Alec

[bobtills212]

I agree about Lucas

Despite being (I believe) known as the Prince of Darkness in the States, I find their products to be of very good quality - far far better than some of the new equivalents you can get today, which last until you shut the garage door if you're lucky.

If I'm looking for parts a Lucas NOS is a far better bet than something made yesterday.