R380 2wd reverse switch

mat_the_cat · Post by **mat_the_cat** » Mon Mar 24, 2014 3:16 pm

Apologies for my first post being a request for help, but hopefully there may be things I can give advice on in the future! I have an early R380 box believed to be originally from a van application (J version). It was freshly reconditioned when I got it but stupidly I damaged the reverse light switch when putting it in the car.

No problem I thought, and just bought one for a Land Rover (AMR3918) on eBay, fitted it and binned the old one. Now, a few months later the electrics are coming together I found that reverse gear was not closing the switch contacts.

A little bit more research showed that the first Landys with this box had a different switch (CDU51L) so I bought that. It was similar but slightly longer, however selecting reverse still didn't close the contacts although it works on the bench. I've even tried it without the copper washer to get a tiny bit more length but still no joy.

So, all I can think of is that the 2wd versions of the box have a different switch, or something inside the gearbox is incorrect. I didn't compare the old switch and it's now long gone. Can anybody shed any light on this please?

ChrisJC · Post by **ChrisJC** » Mon Mar 24, 2014 6:49 pm

I thought the van version was an R5-150 ? If this is so (I am not sure what the actual differences are), it might be a route to explore to see if there is a different part number.

Unfortunately my Freight Rover microfiches are from 1986, so will have the LT77 instead.

Now I have the service book out for the R5-150 and it says formerly 77mm!

Anyway, it says:

1. Switch on the ignition and select reverse gear
2. Fit the switch approximately 3 threads. Connect the wires and continue to screw in the switch until the reverse lights come on. Screw in a further 1/2 turn and tighten the locknut.
3. Return the gear lever to neutral and check the lights go out.

Not sure if any of that is even relevant, but it is all I have!

Chris.

mat_the_cat · Post by **mat_the_cat** » Mon Mar 24, 2014 11:44 pm

Thanks Chris, I must admit the R5-150 was a new one on me. Reverse is below 5th in the usual R380 position, if that helps to confirm one way or another. Also, the reverse switch is in the main body rather than the gearshift remote.

It seems as though the switch isn't designed to be adjustable, as it screws straight in and uses a copper crush washer to seal (no locknut). I've just had a thought that the MG RV8 of the late 90s might have had that box, so might be worth trying to cross reference parts...

If I have any success (or otherwise!) I will post up here for future reference.

mat_the_cat · Post by **mat_the_cat** » Tue Mar 25, 2014 2:38 pm

OK, just to wrap this up I now have reversing lights!

A bit more research showed that the 4wd version of the box have the switch on the LH side and the 2wd versions on the right, on the (different) tail casings. So I was fully expecting to need a different switch, and contacted a Sherpa specialist.

They had one in stock which they kindly measured for me, and it was the same length as the CDU51L I already had! I thought I'd give it one last try without the washer, and this time it worked

I can only think I hadn't fully engaged reverse the first time

I then confirmed that it definitely didn't work with the sealing washer in place, so I don't know whether something still isn't quite right but for now I'm happy...