TD5 Centre Diff Lock

[Ben]

Morning All!

A mate of mine is interested in getting a TD5 Disco, and is wondering about the lack of CDL. Clearly there's an aftermarket unit that can be fitted, but only if the Disco's got the right transfer box.

He's been offered a pretty good deal on a Disco that's about the age where it's pretty much guaranteed not to have the right T/F box.

The question is - how much do you miss CDL - does traction control make up for it?

I guess if it's that good a deal, it might be worth a trip to Ashcrofts!

Cheers

Ben

[thermidorthelobster]

There's an aftermarket solenoid-based unit (Discoparts) or an original-spec Land Rover kit (Ashcrofts sell it).

The answer is, it depends what you want to do with the truck.  For daily driving and green laning, TC will do the job.  If you are doing more serious off-roading then CDL will help take the hard work away from the TC and allow you to drive less aggressively (TC needs a bit of welly to get going).  I've wired mine so the CDL and TC work cheerfully together, so you get the best of both worlds.  There are a few situations I've been in where TC wouldn't get me out alone but with CDL as well it's been easy.

If you're driving hundreds of miles across rocky deserts where TC would be kicking in almost constantly, it's great to be able to switch in CDL and listen to the modulator suddenly stop grinding away.

[Hightower]

I agree 100% with David.  TC will help in most situations, but having the option of CDL as well is sooo much better.  Adding it in (with a Discoparts solenoid) was was one of the first mods I carried out.  Well worth it IMHO.

[andycwb]

I did a couple of hill climbs in the Td5 yesterday, and deliberately tried one with CDL on and off.  The traction control seemed to be working a bit harder with CDL off, but the climb seemed the same pretty much either way.

http://www.cunningham.me.uk/wordpress has a pic of the hill in question.

[andycwb]

I've wired mine so the CDL and TC work cheerfully together, so you get the best of both worlds.  There are a few situations I've been in where TC wouldn't get me out alone but with CDL as well it's been easy.

I'm sure I had the diff lock on with the TC light flashing away yesterday....

[thermidorthelobster]

Yes, if your TD5 was supplied with CDL fitted then it's wired for them both to act together.  But if you fit an earlier TD5 with CDL then by default the SLABS ECU disables the TC if you have CDL engaged.  (It's because it thinks the CDL is only ever going to be engaged manually during dealer servicing, so if it comes on something must be amiss.)

You can modifying the wiring to the ECU quite easily so that it doesn't disengage the TC when Diff Lock comes on, which consequently behaves similarly to the later CDL-equipped models.

Details in the Workshop section of Mud-club.

[andycwb]

Ah.  Now I understand.  


For small values of "understand", anyways.

[thermidorthelobster]

The manual for the early TD5s says if the diff lock light comes on, it's because the dealer's engaged it and forgotten to turn it off, so return it to the dealer.

Mine did come on of its own accord once before I had the actuator fitted;  I think it had just vibrated its way on.  The TC only gets disengaged on startup, so if you haven't changed the ECU wiring you can get around the ECU disabling the TC by only switching CDL in after you've started up the engine.  But then it's a bit of a kerfuffle if you stall.

Ben, by the sounds of it you've already worked this out but if you can get the serial number off the transfer box, you can find out whether it's got the spigot fitted.  (Or of course you can just look for the spigot.)  Ashcrofts say that if it starts 41D or 42D then you're OK;  if it starts 61D, 62D, 69D or 70D then you'll have to shell out another £225 to add in the spigot.

[Ben]

Cheers guys - I'll pass that all on! Very useful information.

I might be in the market for one myself as well, so doubly useful!

Cheers

Ben