Thread: Centre diff light beginning of mods - Anyone fitted a davies electric water pump tdi

I am not all that familiar with D1 but AFAIK there is no light for low range. The light is for centre diff lock.

It is run by the switch riding up a ramp on the diff lock selector shaft so the most likely problem is that the diff lock is remaining engaged.

I would at least get under and see if the arm on the diff lock selector is moving when you change in and out of diff lock.. It is located at the top front left of the nose of the transfer case .

It is not good to be driving on hard surfaces with the diff locked. If you find it is not moving freely jack up a front wheel and then try to move it. This is important as you may blow a differential or CV joint if in diff lock.

Regards Philip A

Thanks Philip A for taking the time to reply.

When you say the diff lock selector shaft, is this shaft different / separate from the low range selector - which certainly was working as had to use low range reasonably frequently on some of the steep tracks - ?

Constantly checked for warmth from the low range lever if the binding was a problem but this has remained cool. Would have thought though that there would be some change in the way the car feels when turning etc.

Will try the jacking up and when someone is available a look at the linkage

Thanks

Arty

I assume that you are aware that you can go from high range to low range and still have the diff locked? The shift is a H pattern. The top of the left hand side is Low range Locked diff, the bottom of the left is High range Locked diff with neutral in between. For everyday driving, ensure that the diff is unlocked by moving the shift into neutral and then to the right.

Cheers

When you say the diff lock selector shaft, is this shaft different / separate from the low range selector - which certainly was working as had to use low range reasonably frequently on some of the steep tracks - ?

Yes as stated above , if you move the lever to the left you engage the diff lock.

The switch works off the selector shaft inside the transfer case.

The light on the dash should be like a wide "H" with a lump in the middle which recognizes that the four wheels are locked together.

Regards Philip A

As already said, left-right is the CDL, light is on for that, not low range.

Move lever left and right a few times to free it up a bit more.
You can move into CDL locked and unlocked whilst driving(up to 100 k/h I think).
Just don't shift whilst driving and spinning any wheel! (an unlikely situation, but good to be aware of it).

Tdi can be a great little motor.
In terms of gauges, I'd say probably more important than EGT and turbo gauge is water/engine temp gauge.
Coolant temp gauge can be handy to have, but it only works at a preset temp.
I think it's better to know that the engine is heating up, given certain conditions(eg. towing/loaded ... long uphill climb, just a flat out hot day out and nothing you can do about it! )

Reason I say that is because mine doesn't run hot, or heat up ever! .. except under specific situations.
No matter how hot outside(I've tested up to 44°C), my max coolant temps, up hill or down, or free wheeling or whatever) .. usually about 88°C max, generally 80-85.
But I recently had an issue when I ran air con, in ambient over about 35-ish degrees, I'd see coolant temps in the 110 range if not kept in check.
That is, not watching the temp gauge like a hawk, but over say a 5min period, a quick glance would confirm coolant temps rising. More so uphill. EGT would always rise at the same time, in fact I think higher EGT would be causing the coolant temp rise.

Anyhow, sorted it out to a reasonable situation now(made a scoop) but something to be aware of.
The dash gauge is totally useless, up to about 117-120°C coolant temp.
Make sure all your hoses are in good nik .. triple check the two hoses up top, back of engine for the heater matrix. On mine, one was leaning on the head, at the corner, hot aluminium vs rubber hose, aluminium always wins .. burned a small mark that WAS gong to become a holed heater hose. disaster averted.

I'd say that 235/86's on a D1 on a standard Tdi, may be a bit too tall(gearing). You may want to think about defender transfer case gearing at the same time too.
Are you manual or auto?

.. anyhow .. definitely move that high-low lever left-right a few times to help free up the CDL mechanism.
Note that sometimes it can take a short while after you've unlocked the CDL for it to unlock.
when I got mine, owner didn't know how it worked(or what it does), so hadn't used it for at least 5+ years. maybe more if previous owners before them never used it either.
ON first lock, it took about 500m to turn on, much reversing .. etc to get it to come on.
Then once it came on, it took longer to get it to come off. Gravel road, I'd say a bit more than a couple of klms, two shots one U turn. No snatchy feeling in the driveline when doing the u turn. So I think the actual diff turned unlocked, but maybe the light switch was a bit gummed up inside and slow to react switch plunger caused the light to stay on
Maybe .. dunno, has operated perfectly as expected since that road test before buying it!

Thanks blokes, the lever was in the left position and took a fair amount of force after in and out of low and back, so not sure how I put in diff lock in the first place. Re reading the manual and there are no arrows or indication of the two sided nature let alone a description of put the lever to the left or right, still feel a bit of a klutz

AK83 the Disco is a sweet changing manual and upshifts clutchless without problem but due to the long travel nature of the accelerator pedal clutchless downshifts require a deliberate and rather slow change.

Was more than happy with the descent against the engine breaking and grunt up step climbs and would lose a proportion of this with 235 85's as would a degree of forward progress on the open road, 2500 at 100 kph (gps) easily maintained, that is no problem up most hill and dales. The boost pin and incremental gain of loss of the water pump (give me at least 3KW in total or 10% of total power LOL) would make the gain on open road, be interested in others use of these in the wild and if it does impact on the trails.

As far as temp, mostly 85-87 in normal driving, hit 92-94 up the steep tracks in low low and spiked at 100 when stopped for anothers vehicle cavitation of the clutch fluids, settled straight back once restarted. Previous owner told me he regularly replaced the pipes and they look reasonably new, will keep this up with a change over to silicon but done in parts with the first one when fitting Davies Electric Waterpump to the lower pipe

by the way, light went off straight away, no delay

Have watched this with interest & glad all seems ok now.


It doesn't help with the knob fiddling that the cup holder keeps on getting opened & in the way. Another LR design cockup IMHO.