TR4/4A overdrive solenoid rubber boot

Hi all
Another OD thread. Just checking mine out and noticed that the rubber boot on the solenoid is cracked up and would no doubt let water into the bits.
Moss (I'll leave comments aside) has what they call solenoid cover for $44 (#680-210) or a whole solenoid aftermarket with cover for $37.99 (#145-722)
Original Lucas N/A $145. The boot part number is Lucas 765063 I think
What's the story?

I'll certainly looks like, assuming you trust the aftermarket solenoid quality , that would be one way to go. Sometimes different supplier such as the roadster factory and Victoria British have a slightly different inventory of parts available, might be worth checking there too.

Yeah, $44 seems pricey for just the boot.

FYI - here is what is claimed to be an NOS Lucas for about 30 bucks:

https://www.ebay.com/itm/NOS-LUCAS-...CLASSIC-CAR-/291578531980?hash=item43e36f508c

I think 76515 is the correct A-Type unit but check before purchasing. Even with shipping from the UK that seems reasonable.

The last aftermarket solenoid I got certainly didn't last nearly as long as the original. I'm hoping this mod will help the next one last longer

EDIT: Turns out I goofed. I still think the diode in the solenoid concept is sound, but the way I wired it won't do any good. So I deleted the photo.

Geo Hahn said:

Yeah, $44 seems pricey for just the boot.

FYI - here is what is claimed to be an NOS Lucas for about 30 bucks:

https://www.ebay.com/itm/NOS-LUCAS-...CLASSIC-CAR-/291578531980?hash=item43e36f508c

I think 76515 is the correct A-Type unit but check before purchasing. Even with shipping from the UK that seems reasonable.

Click to expand...

Strange that it doesn't have the Lucas style boot, and doesn't appear to say 'Lucas' anywhere on it. But 76515 does appear to be the correct Lucas number.

Good tip fromTDskip. Victoria british has the solenoid on sale for $30 + $10 shipping

I used a diode as suggested above by Randall. This one:



On my positive ground TR4 I attached it at the relay thusly:

Hi Geo and Randall
Radio Shack is no longer local to me
3 questions.
1. what is the diode part number (a little hard to read 276-1661 or 1861?). For Neg ground do you just reverse the diode?
2.What benefit do you get from the diode?
3.What do the transmission isolator switches (#57 in your schematic) do? I had assumed that they were 3rd/fourth gear enabled but mine do not seem to have any continuity between the terminals no matter what gear is selected. The manual is no help here.
Thanks

I am not the electronics expert here - I'm better at recognizing a good idea than actually having them. That said:

1. P/n is 267-1661. Yes, reverse the diode for negative ground (I think that is what Randall's schematic shows).

2. I've always called it a snubber diode but apparently flyback is also a term. Wikipedia entry here.

3. Those isolators provide a groundpath for the solenoid only when an appropriate gear is selected. On an A Type - one for 3rd or 4th and one for 2nd.



The isolators can be adjusted for depth to make them work as intended. Sounds like your either need adjustment or have failed altogether.