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[Viral_Jim]

Following two non-repairable punctures in as many months, I am looking at getting a new pair of boots for the Disco. To do this I need to shuffle the wheels around to get like-for-like tyres on each axle (both punctures are driver’s side, front and rear). What’s on it are some sort of all weather thing that are close to £300 each. I really don't need this capability, so I won't be bothering with those! Good mid-range tyres are a little over half that, budgets, well under half.

This raises two questions. Firstly, if I shuffle the tyres will I have to get the car hooked up to a spotty yoof’s laptop to get the TPMS reshuffled, or does it know which sensor is where on the car without being told? Secondly, will running different tread levels front to back have any negative effects on the drivetrain? I’ve heard about some 4x4 being ‘sensitive’ to differing tread depths on tyres and I was previously planning on rotating the tyres and replacing all four at once when worn.

[TheBoy]

Can't comment on the TPMS system fitted to that, but the system fitted to my XJ is self learning, it just takes a couple of journeys with a 30 min stop between it seems, for it to learn the new wheel positions.

[TheBoy]

I imagine the later systems fitted will be broadly similar.  But if nobody knows, PM me the reg, and I'll try to take a gander on TOPix...   ...although I'm away for a few days in some miserable place in Suffolk, so might not be prompt to respond

[VXL V6]

On a similar subject

I enquired at BMW for tyre prices when I dropped off the car for the EGR Cooler recall the other week as it will need new rear boots (275/35/19 Runflats) and was surprised to find that they can supply the same tyres as currently fitted (Michelin Primacy ZP's with BMW OE * markings) for £30 less than an independent can supply non-BMW OEM * marked versions.... Given mine also has TPMS my thinking is if BMW break the modules when fitting the tyres then that's their problem!

[TheBoy]

The machines shouldn't go near the valves, so they should be hard to "break".  I suspect if they did manage to break them, somehow it would be your fault and chargable though

I bought 4 new genuine JLR TPMS sensors and valves for a spare set of wheels I acquired for the XJ, £45 for all 4.

[Rangie]

I've had various 4x4s since 1987 & have always replaced tyres 4 at a time as this is the advice I was given to ensure no problems are encountered with the vehicle, I have never had any issues after following this advice, some members on the RRS forum have had issues with varying tread depths.

[ronnyd]

I imagine the later systems fitted will be broadly similar.  But if nobody knows, PM me the reg, and I'll try to take a gander on TOPix...   ...although I'm away for a few days in some miserable place in Suffolk, so might not be prompt to respond

The sun always shines in Suffolk. 

[Doctor Gollum]

Goodyear Eagle F1 Assym 3 SUV on the Alabama Mumsybus to good effect 

The idea of replacing all four tyres is about protecting the transfer box and something that I first encountered on my old Sierra XR4x4. Which incidentally had a chain driven transfer box with a pair of viscous clutches, as does the Alabama Mumsybus. 

[Sir Tigger KC]

I thought the 4x4 tyre issue was more about AWD Haldex systems as found in cars like Audis rather than 'proper' 4x4's like a Discovery? 

Although I'd imagine that the transfer box in a Disco 5 is a very different beastie to that found in a Defender or earlier Disco, so I'm probably talking out of my arse. 

As usual! 

[Marks DTM Calib]

Proper transfer box so no tread depth matching issues.

TPMS system does learn the location of the tyres over a few miles so nothing special needed

[Marks DTM Calib]

Goodyear Eagle F1 Assym 3 SUV on the Alabama Mumsybus to good effect 

The idea of replacing all four tyres is about protecting the transfer box and something that I first encountered on my old Sierra XR4x4. Which incidentally had a chain driven transfer box with a pair of viscous clutches, as does the Alabama Mumsybus. 

That's not a 'transfer' box in the traditional sense, it's a torque vectoring unit (a similar PUCH one was used on Cav and Calibra 4x4s). These can suffer with tyre tread mismatch, but its dependent on the 'flavour'. The good ones use fluid couplings to apportion power front rear

[Andy B]

.....
 (a similar PUCH one was used on Cav and Calibra 4x4s).  ....

And look how successful they were .... 

[Viral_Jim]

TPMS system does learn the location of the tyres over a few miles so nothing special needed

Good news indeed, thanks Mark.

I bought 4 new genuine JLR TPMS sensors and valves for a spare set of wheels I acquired for the XJ, £45 for all 4.

That seems extremely good value! Were these from JLR direct, or an eGay find?  EDIT: a quick look online seems to indicate they are the same part number as for XJ 2010 on - LR070840

On the subject of TPMS, roughly how long are they supposed to last (assume for these lifespan in years is more relevant than miles?)? If they aren't that dear I might get them replaced when the next two tyres need replacing. Would probably be about 5.5yrs / 60,000 miles old by then. 

[Marks DTM Calib]

.....
 (a similar PUCH one was used on Cav and Calibra 4x4s).  ....

And look how successful they were .... 

They were superb if looked after, needed 50k mile oil changes, matched tread depths, and accumulators changing occasionally. Of course, most didn't bother!

Well-maintained units would do 200k miles with no issues, no different to the Haldex and slipper systems of today 

[Marks DTM Calib]

TPMS system does learn the location of the tyres over a few miles so nothing special needed

Good news indeed, thanks Mark.

I bought 4 new genuine JLR TPMS sensors and valves for a spare set of wheels I acquired for the XJ, £45 for all 4.

That seems extremely good value! Were these from JLR direct, or an eGay find?  EDIT: a quick look online seems to indicate they are the same part number as for XJ 2010 on - LR070840

On the subject of TPMS, roughly how long are they supposed to last (assume for these lifespan in years is more relevant than miles?)? If they aren't that dear I might get them replaced when the next two tyres need replacing. Would probably be about 5.5yrs / 60,000 miles old by then. 

I ssked this of the TPMS team a few weeks ago when they were hogging the airline at the work fuel station. The answer was 7 to 10 years typically but, there was also a mileage factor or 'time in motion' as they communicate when moving