alisterg
Trekker
This morning, I finally got round to doing something I've meant to do for a long time.
Most of you will know that on the R380 gearbox used in a whole range of Land Rover models, including the Defender TDI, Discovery 1 and 2 and some Range Rovers, the reversing light switch is a plunger type which screws into the side of the gearbox casing, and is positioned such that when the gearbox is in the vehicle, it is very hard to get to, because of the chassis rail, transmission tunnel, and gearbox mountings all getting in the way. You only have a 2 to 3 inch slot up the side of the gearbox to get at it, and putting a spanner on it is very difficult.
The switch is actuated by a notch in the gear selector shaft for the reverse gear, and over time this notch wears away, until it doesn't actuate the switch any more. It is common for higher mileage vehicles not to have working reversing lights - or for them only to work if you grab the gear lever and force it further backwards whilst you try to reverse.
The only fix is to dismantle the top of the gearbox and the selector housing, which on the Discovery means removing all the centre console trim, disconnecting the handbrake, drilling out 20-some rivets and other horrors, and finally replace the reverse gear selector shaft - just changing the switch doesn't fix the problem.
I've had three vehicles with this problem, over recent years, a Defender 90, a Discovery TDI and now a Discovery TD5.
I finally had enough - and also reversing lights are now part of the MOT if fitted, I believe, so as the dreaded day is approaching I decided to do something about it.
I thought I would try a bit of keyhole surgery, so I removed the gear knob and gaiter to see what I could find, and to see if there was room to fit an alternative switch.
Here's what you get:
You can see I've cut away some of the soundproofing material to get a better view:
So after some thought I came up with a plan.
I made up a small bracket from some brass sheet. This will be attached to the side of the transmission tunnel, and will hold a microswitch to switch the reversing lights.
Here you can see the mounting holes I drilled for the bracket:
And here's the bracket in position:
Onto the bracket I then attached a microswitch with a long actuator arm:
I discovered whilst testing that the arm was too long, and the gear lever hit it when selecting fourth as well as reverse, so I shortened it by bending the end round:
Here it is with fourth selected:
And then with reverse selected:
Then, using the plug from an old reversing switch, I extended the wiring from the existing feed, and routed it up to the new microswitch:
I then spent some time testing that selecting reverse would reliably turn on the lights, without having to be especially careful or anything.
Finally I replaced the sound proofing material, cutting away at the underneath so it wouldn't foul the switch:
Finally afer more testing that the switch worked with the soundproofing in place, I replaced the gear knob and gaiter.
Job Done!
All told, it took 2 hours, and I now have reliably working reversing lights, and should the switch fail, it's only a 5 minute job to replace it, without having to crawl under the car and trap my knuckles between the chassis and gearbox! Win Win, I reckon!
Thanks for looking,
Al.
Most of you will know that on the R380 gearbox used in a whole range of Land Rover models, including the Defender TDI, Discovery 1 and 2 and some Range Rovers, the reversing light switch is a plunger type which screws into the side of the gearbox casing, and is positioned such that when the gearbox is in the vehicle, it is very hard to get to, because of the chassis rail, transmission tunnel, and gearbox mountings all getting in the way. You only have a 2 to 3 inch slot up the side of the gearbox to get at it, and putting a spanner on it is very difficult.
The switch is actuated by a notch in the gear selector shaft for the reverse gear, and over time this notch wears away, until it doesn't actuate the switch any more. It is common for higher mileage vehicles not to have working reversing lights - or for them only to work if you grab the gear lever and force it further backwards whilst you try to reverse.
The only fix is to dismantle the top of the gearbox and the selector housing, which on the Discovery means removing all the centre console trim, disconnecting the handbrake, drilling out 20-some rivets and other horrors, and finally replace the reverse gear selector shaft - just changing the switch doesn't fix the problem.
I've had three vehicles with this problem, over recent years, a Defender 90, a Discovery TDI and now a Discovery TD5.
I finally had enough - and also reversing lights are now part of the MOT if fitted, I believe, so as the dreaded day is approaching I decided to do something about it.
I thought I would try a bit of keyhole surgery, so I removed the gear knob and gaiter to see what I could find, and to see if there was room to fit an alternative switch.
Here's what you get:
You can see I've cut away some of the soundproofing material to get a better view:
So after some thought I came up with a plan.
I made up a small bracket from some brass sheet. This will be attached to the side of the transmission tunnel, and will hold a microswitch to switch the reversing lights.
Here you can see the mounting holes I drilled for the bracket:
And here's the bracket in position:
Onto the bracket I then attached a microswitch with a long actuator arm:
I discovered whilst testing that the arm was too long, and the gear lever hit it when selecting fourth as well as reverse, so I shortened it by bending the end round:
Here it is with fourth selected:
And then with reverse selected:
Then, using the plug from an old reversing switch, I extended the wiring from the existing feed, and routed it up to the new microswitch:
I then spent some time testing that selecting reverse would reliably turn on the lights, without having to be especially careful or anything.
Finally I replaced the sound proofing material, cutting away at the underneath so it wouldn't foul the switch:
Finally afer more testing that the switch worked with the soundproofing in place, I replaced the gear knob and gaiter.
Job Done!
All told, it took 2 hours, and I now have reliably working reversing lights, and should the switch fail, it's only a 5 minute job to replace it, without having to crawl under the car and trap my knuckles between the chassis and gearbox! Win Win, I reckon!
Thanks for looking,
Al.
Last edited:
