Had a non-repairable puncture on rear tyre a few weeks ago, all four tyres were same mileage and 50 to 60% wear remaining. I decided to replace both rear tyres with same brand/spec, no change to noise level but within 2 weeks the dreaded transmission whine started. Now getting worse and planning a visit to Austen at Bell Eng, all transmission is original and has done 60k miles.
Should I have replaced all 4 tyres? I can find two directly related threads on this forum and the comments are quite inconclusive, however a google of "4WD replace all four tires" shows a large majority of comments that 4WD should have new tyres replaced only x4 (not just from tyre companies or retailers).
Of course my experience could have been a coincidence. Any comments please.

Its a expensive call for one puncture and there will be no right answer as had the FL2 not got a weakness in the rear diff construction most 4X4 owners would get away with doing what you did. Maybe all you have done is bring on a failure waiting to happen just that bit sooner but see what Austen has to say first.

Have you tried moving the tyres front to rear to see if it stops the problem. FL2 MY10 TD4 GS traded in at 2 years
FL2 MY13 TD4 GS Current

Changing all 4 tyres with a reasonable amount of remaining tread when one tyre dies is a conspiracy to sell more tyres. Procrastination, mankind's greatest labour saving device!

Acoustic insulation ARB TPMS 3xARB air compressors After cooler Air tank On-board OCD pressure air/water cleaning Additional 50L fuel Carpet in doors ABE 2x1kg Waeco 28L modified fridge Battery 4x26ah Solar 120w Victron MPPT 100/20 DC-DC 18amps 175amp jumper plug Awning 6x255/60R18

I would 1st do what York Bob has advised try moving the tyres front to back but don’t automatically think it’s the diff it could be a wheel bearing.

It's not a problem with your tyre situation.

As YB stated, probably a problem just waiting to manifest itself. FL2 now gone and have a couple of items left for sale:-

Brodit active iPhone holder + Brodit dash clip,
Bluetooth Music Streaming Module.

I've had different fronts and rears on mine several times. I"ve also had tyres with different amounts of wear and had no trouble. My diff was repaired under warranty before all this 8 years and 230,000 kms ago. The car is on 307,000kms now.

Yep.....I agree with all previous posts that changing tyres as you have done (and what I would have done) is not the cause of your problem

What year and mileage is your FL??

Steve

thanks for the comments and advice.

Jenks - car is MY2009 at 60k miles. I suspect it is transfer box as noise is more noticeable during turns with load on. That is why I thought possibly differing tyre diameters may put an extra load on transfer/PTU. It would be good to be able to definitely discount wheel bearings before a trip to Bell Eng, interestingly it has been quietish for first few miles each day.

So that is not a very high mileage, but with the year, I guess it could be any of wheel bearing, diff or transfer unit.

My feeling for the tyres is based on the fact that the manual only says it is "preferable" to replace tyres in pairs which all makes sense.
In normal driving, the wheels are all covering different distances anyway and with the Haldex and diffs on a FL there should be no transmission "wind up"

Steve

The main thing here is to maintain the same rotational speed for both front and rear axles.
In this way, in straight line, if the difference in rotational speed between axles tends towards zero, then the PTU and Haldex are less solicited, even if the Haldex is in full lock.
As for when cornering, the system is programmed to release a little, towards a reasonable/compromise value, the Haldex torque transfer, in order to not damage the PTU and/or Haldex.

All in all, in my opinion, the tire pressure is more important (as affects more and quickly than a worn tire) the total rolling radius, leading to differences in rotational speeds and therefore, in time, a damaged PTU and/or Haldex.
Check at least weekly the tire pressures and keep them equal.

Whilst travelling vast distances around Australia, over a day I noticed how much tyre pressure varied around the car depending on where the sun was & this was not even during our stinking hot summers where you do anything to get a bit of shade. The difference could be up to 4 PSI showing on the TPMS from the shadow side of the car to the sunny side. Procrastination, mankind's greatest labour saving device!

Acoustic insulation ARB TPMS 3xARB air compressors After cooler Air tank On-board OCD pressure air/water cleaning Additional 50L fuel Carpet in doors ABE 2x1kg Waeco 28L modified fridge Battery 4x26ah Solar 120w Victron MPPT 100/20 DC-DC 18amps 175amp jumper plug Awning 6x255/60R18

When I did my rear diff I asked Austen Greenway his opinion on only fitting a new pair of tyres at a time. His response was that it was ok to change them in pairs & it made no difference to which axle they were fitted to either. His only stipulation was to stick to the same make/model of tyre, due to the differences in manufacturer sizes!

Therefore, if you want to change to a different make/style of tyre, change all four at the same time.

Cheers,

Nick (Now Sold). 2008 Freelander 2 (Nazca Sand) SE TD4 Auto. Statutory write off & on WOVR for hail damage but still road legal.
171037Km as of 09/05/22
Superchips Bluefin Flash
Nanocom Evo II (also sold)

Just so we do not panic too much!

For example you have 3 old tyres on the car & have replaced 1 destroyed tyre with a new tyre. We are using 235/60 R18, new diameter 639 mm. Front left wears the quickest.

FL 629, FR 630
RL 639, RR 631

0.866% difference front to rear.

If you feel stressed over this difference pump up the front tyres another 2 PSI to give a slightly larger rolling diameter due to a smaller flat contact area with the road & let down the new tyre 2 PSI.

36 PSI, 36 PSI
32 PSI, 34 PSI

& you would be hard pressed to measure much difference between front & rear. Procrastination, mankind's greatest labour saving device!

Acoustic insulation ARB TPMS 3xARB air compressors After cooler Air tank On-board OCD pressure air/water cleaning Additional 50L fuel Carpet in doors ABE 2x1kg Waeco 28L modified fridge Battery 4x26ah Solar 120w Victron MPPT 100/20 DC-DC 18amps 175amp jumper plug Awning 6x255/60R18

My last set of tyres were badly worn on the inside more than the outside, probably because the rears splay outwards if you look from behind. Anyway, it sounded like I needed a new diff or wheel bearings in the back, the noise was bad. I put 4 new tyres on and it's nice now, so the tyres make a big difference.

As above almost exactly the same situation I had, bought a FL2 which had 1/2 worn Pirelli Scorpian on the front and 3/4 worn Goodyear Wrangler on the rear......at speed on the drive home it sounded like the rear diff/wheel bearing was about to disintegrate, very worrying.

All usual bits checked by my local garage and declared quiet on the wheels free and no play detected, only issue they pointed out was the rear Goodyear’s had a strange looking wear pattern.

Complete new set of Michelin’s fitted and the car was like a different machine, all noise completely gone.

PHEW  Regards

David

Lovely i6 has now gone, but not me......

Please let me know if anything in my post offends you, as I may wish to offend you again......