Reverse switch on a ZF box

[Andrew S]

Where is the reverse switch fitted on a ZF box, on top or side and is it the same as the Lucas Stag one?

Cheers
Andrew

[new to this]

Andrew

Do you know what ZF box it came from, eg Rover ,Jag, LDV ,first place to look is around the gear sector mech ,or end of Box

Dave

[Seaking]

IMG_20191111_185022.jpg Andrew the bmw is in the gear shifter see the yellow part in my picture.. I had to cut the tracks and fill in some but it works for reversing lights and inhibitor switch . It was from a bmw e30.
Cheers Glenn

[alan_thomas]

On my latest conversion I have just fitted an inhibitor SW from a ZF4HP14 box it is similar to the ones fitted to the Landrover boxes but it screws into a M18 thread rather than a hole with a retaining clip. All ZF4HP22 boxes that don't have an inhibitor SW fitted still have the actuator cam internally and there is a depression in the casting where the hole needs to be drilled. You need to drill and tap the casing so some disassembly of the box is required to make room for the drill and tap and it goes without saying the box will need a rebuild to ensure no swarf remains.

ZF4HP14SW.JPGDSC05289.JPG
ZF4HP14 switch fitted before box was rebuilt, switch is like the BW35 one but the size of the BW35 sw makes it impossible to use.

DSC05290.JPG
rebuilt box with Landrover inhibitor sw fitted. Both switches have 2 sets of contacts, one pair turn on the reversing light the other pair limiting starting to 'P' and 'N' so they connect to the same wiring as the original Stag Switches.
- Alan

[DJT]

Hi Alan,

I have a reverse/inhibitor setup cobbled together by Ian Coe when he ran Monarch. It also included an electro-mechanical speedo. I have replaced the speedo with the new electronic one, but still have the reverse/inhibitor setup operated by optical switches beside the gear-lever. I wish I knew about your solution (above) when I was doing my box. I have removed the sump pan on my spare ZF and, indeed, it does have the internal cam operated by the shift lever. It looks as if the front pump housing has to be removed to get the correct angle to drill/tap the necessary hole. Something to consider should I have to remove the fitted box for rebuild at some time in the future.

Do you have a source for the switch? Looking on eBay for a ZF4HP14 switch comes up with en ex-Daewoo item with a plug socket on a flying lead. I can't seem to find one with 4 Lucar connectors like the one you have used.

How is the LR switch secured into the box?

[alan_thomas]

Yes to fit the inhibitor switch the pump housing needs to be removed. I have seen these screw In switches with various connections and attached wiring and all do the same job. The landrover switch has a plain barrel body and is held in place with a ‘spring steel fork’ which is in turn held by a single small bolt into a threaded hole. The hole is drilled in a small pad cast in the housing.
I can probably dig out a pic of you are interested
- Alan

[DJT]

Thanks Alan. A photo would be helpful.

[new to this]

How tight a fit is the gearbox in the tunnel area by the gear sector mech, thinking about fitting a switch on the outside of the gearbox

Dave

[Seaking]

Dave look at this link post 7 onwards(OR DO A SEARCH , My ZF4 CONVERSION, SEAKING) https://www.google.co.uk/url?sa=t&rc...vqdWpb5nYMy8Gn but if you use a landrover switch do not use a 16mm drill its too large .

Cheers Glenn

[alan_thomas]

Thanks Alan. A photo would be helpful.

Glenn has posted a link to his conversion thread, a couple of the pics on his post 8# really show the switch well - Alan

[DJT]

Thanks Glenn and Alan. I’ve saved the pictures. Just need to source either of the switches and, if it is a LR one, a spring clip. I’ve found the LR one, RTC4937, online but it ain’t cheap!

[Seaking]

No Dave they are not cheap could try a land rover breaker

Cheers Glenn

[new to this]

Dave look at this link post 7 onwards(OR DO A SEARCH , My ZF4 CONVERSION, SEAKING) https://www.google.co.uk/url?sa=t&rc...vqdWpb5nYMy8Gn but if you use a landrover switch do not use a 16mm drill its too large .

Cheers Glenn

Glenn

Thanks,ill see if i can get the Jag switch to work with a spacer,

Dave