Hi,
just a thought did they clean the plastic gauze filter as well as replacing the oil and main filter

if not there could be restricted flow.

best of luck

 .
my first ever FL2 and I did keep it longer than most other cars!
But its now gone way up Norf

Yes, they replaced the main filter and cleaned the gauze - twice.

Took it out again today. No issue maneuvering out of the parking bay, but then about 200m up the road, 50m after coming out of a junction, but on an otherwise straight bit of road there were a couple of very noticeable thuds/bangs through the drivetrain and a brief squeal. Then it all settled down and I drove around 30 miles with no issues whatsoever. Even doing tight circles in a gravel car park, reversing round corners on tarmac, roundabouts etc do not cause any problem once I get past the first 300 yards and the initial thuds/bangs that you can most definitely feel through the whole car.

I'm now wondering if it might be something else as surely a Haldex issue would be most noticeable on tight corners. But this issue is so far only occurring within the first 1/4 mile of any journey. I'm wondering if my parking brakes are binding or snatching.

Sounds more like the PTU or the splines from the gearbox to the PTU are failing.

Before mine failed the were occasional bangs that I thought were the diff. The splines between the gearbox and PTU were shot and skipping, eventually they let go and I was left with rear wheel drive and a very quiet driveline. Tangiers Orange - gone, missing her
Replaced by Ewok what a mistake - now a happy Disco Sport owner

Having never experienced failing PTU splines I don't know, but this is happening under quite gentle loads and its only happening shortly after being parked up for some time. Once I have done that first 1/4 mile I can floor the accelerator all I want out of junctions etc and everything is fine.

I did also here a "twang" pulling on the hand brake a couple of weeks ago shortly after the car passed its MOT test, but thought nothing of it. The hand brake otherwise appearing to function correctly.

Will be doing more investigations today.

Investigated some more this morning.

It's not the brakes as removing the Haldex fuse stops the problem.

Drive out of the street I live in, do a sharp left hand turn and once going straight again there is a gentle thud that can be felt through the car. Go 100m, turn right and once on the straight gently pickup speed to around 20mph and there is a very brief chirp a little like a slipping fan belt noise, sounds like rubber, not metal and two thuds.

From there I go around a roundabout and on to another road all without drama or strange noises.

Went into a small car park, reverse on full lock, either direction, no issue. Pull out of the car park at full throttle all fine until I straighten up on the road and hit approx 25 mph and I get a single thud, not terribly pronounced but it was there.

Another car park, full lock circles, reversing, all fine. Drive back home accelerating as hard as I can out of junctions no issue, no more thuds, no scrabbling wheels.

Then I let the car cool down for a few hours. Remove the Haldex fuse and take it for a drive. As expected no thuds, no drama, so not brakes. Stop the engine. Replace the fuse, drive away and as I pick up speed on a straight bit of road I get a gentle thud. But after that no more thuds.

It's very odd. It seems that after initialising the Haldex, whether at the start of a journey or after replacing the fuse I get these thuds. Not while going around corners but on straight sections of road and not necessarily when accelerating hard. Each time it seems to happen after a turn, once I am straightening out and at around 20-25mph - is this the speed the Hadex disengages? Once I've driven for a bit or after gone some distance after refitting the Haldex fuse they do not occur no matter how I drive and I still have 4 wheel drive.

From this I conclude that the Haldex is locking - no wheel spin, and releasing - no problem maneuvering at full lock.

I do know from experience with other vehicles with a locking center diff that releasing the diff while loaded up will produce a quite dramatic thud, which is what this feels like, but then the PTU splines slipping would likely feel almost exactly the same.

So that leaves:

PTU splines slipping. But why only within the first 1/4 mile of when the Haldex fuse is fitted or a new journey started. Never later, no matter how hard I drive. How can I determine if the splines are shot without removing the transfer box? While I can't rule out the splines, it just doesn't seem that's the issue and I didn't have this issue prior to the diff rebuild and Haldex filter/fluid ​change just 150 miles ago, all this has started since the Diff/Haldex were removed, hence mine and the garages thinking this is the Haldex.

Haldex issue between locked and released that settles once it has run for a bit - Maybe the pump is on it's way out and not building enough pressure or maybe the n373 valve sticking, in another thread another owner had a "thudding" haldex after a oil and filter change that was cured by replacing the n373 valve (£70 valve).

So I am considering:

1 Cheapest/easiest option - replace the n373 valve, top up the fluids and test. Maybe it will, maybe it won't.

2 Pull off the haldex again, strip and clean again, this time removing and inspecting the clutch packs, motor brushes, replace n373 valve. Outcome unknown. Probably cost 3 hours labour plus valve and fluids.

3 Buy a salvage Haldex, strip, clean including clutches, refit. 3 hours labour plus £300 for Haldex, plus fluids and filters. Outcome completely unknown - not keen on this option.

4 Remove the PTU to inspect the splines. Replace PTU and coupler if necessary - the most expensive option.

5 Drive it until whatever it is fails completely hopefully making it very obvious where the issue is.

I hate uncertain issues. I can afford to fix this if I can pin it down, but I can't afford to throw money into replacing parts that might not be broken and then have to repair another part of the transmission. Just wish I could isolate the exact cause.

Good grief pal what a pain.

I would seriously consider an appointment with Austin & a trip to his place at Bell engineering, being you are based in Berkshire - not an horrendous journey, the guy is the dogs plums when it comes to FL2 transmissions.

Go on treat yourself.



Cheers
Brian

If Austin wasn't fully booked up all the way to the very end of September, trust me I would, but I can't wait nearly 3 months. I would have got him to do the diff too but it was a 2 month wait.



For now I'm going to try changing the solenoid valve as this is very easy to do and only £60 plus fluid. Really not convinced about PTU splines. I had no thuds before the diff was done and the Haldex serviced. I do have 4WD and I don't get scrablling or bangs/thuds on tight turns. Even when the rest of the car is warmed up I only get the thuds within the first mile of putting the Haldex fuse back and it's always around 25mph range where I believe the Haldex should be smoothy releasing.

Removing the Haldex fuse disconnects the rear diff from the propshaft, so there is very little load on the PTU. Once the car picks up speed it becomes front wheel drive so again very little load on the PTU.

Once the coupling fails it trashes the PTU, change the coupling and you will probably get another year or more out of the PTU

I am biased, whipping out the RH driveshaft and PTU would be for me a pleasant weekend playing with the spanners, rather than a costly exercise at a garage. Tangiers Orange - gone, missing her
Replaced by Ewok what a mistake - now a happy Disco Sport owner

Also thermal expansion coefficients can cause mechanical parts to change their behavior depending on whether they are hot, cold, warming up or cooling down. Splines and CV joints would be sensitive to that.

It depends on the specific metals involved, so there's no consistent rule of thumb on that.

Still not buying PTU splines.

1: There was no issue the day before the removal of the diff and haldex which was working fine. But after refitting the diff and haldex the issue is very suddenly present. The PTU hasn't been touched, the Haldex has. After driving the car back from the garage without any drama, enjoying my nice quiet diff, the following morning the Haldex was locked up from the moment I moved out of it's parking spot with the wheels scrabbling on tight turns and reversing. I got maybe 300m before I abandoned my journey and then it was on the recovery truck back to the garage who confirmed it was locking up so they removed it, flushed it and refilled again and at first thought the issue to be resolved. But although now significantly better/different an issue remains.

2: Why does the issue only happen within a short distance of replacing the Haldex fuse? After everything is warmed up and up to temperature replacing the Haldex fuse causes the issue to immediately start again, a few thuds as soon as the car gets up to around 25 mph all within the first 1/4 of a mile then without fail after 1/4 of a mile all is good and I can drive it like a lunatic and there are no dramas, stop, start, slow fast, there is nothing to suggest anything is wrong, even after a 50 mile drive. Remove the fuse, drive around in 2WD for a bit, replace the fuse the cycle repeats, a few thuds and then it's back to being fine again. The PTU will be at pretty much the same temperature as the gearbox regardless and the thuds occur whether the cars been driven hard or stone cold - but only ever a couple of times and within the first 1/4 mile of replacing the Haldex fuse. Why not further down the road, temps and loads should all be the same.

3: Why do the thuds almost always happen at the same speed - 25mph, not more, not less, under load or not under load, same speed, roughly the point where the Haldex dissengages.

The garage who are Land Rover specialists and have driven it and experienced the thuds have seen their fair share of stripped splines and they say it doesn't sound or feel like PTU splines. Although like me they can't categorically say it isn't PTU splines they are still convinced it's the Haldex but also cannot say precisely what the issue is as they have never seen anything like this before and couldn't find anything obviously wrong with the unit when they stripped it the 2nd time.

I'm going to try the solenoid valve as this has cured remarkably similar issues for others - haldex filters changed, fluid replaced - thuds and bangs on straight roads afterwards, further fluid changes ineffective, change the solenoid and the problem stops. If that fails I'm not sure what the next step will be.

Sorry to hear your troubles. My haldex has not been serviced in 203000km. I'm about to do it myself I don't think it can be left any longer so I'll report with some pics in due corse.

That's when I did mine for the first time (122K miles), it never gave me any trouble. I live in San Diego so similar climate to Oz.

Careful removing the prop shaft bolts, I sheared one off. Use a heat gun (or gentle heat with a torch) to help loosen them.

Now I know exactly what the issue is.

Went to replace the solenoid valve. Got under the car noticed small quantities of dripping fluid (again - I raised this with the garage the very first time it went back). Some of the drips look almost clear, others are golden and smell of diff oil.

Got the car up on ramps under the rear wheels only so the rear of the car is well in the air. lying under the car I undid the filler for the Haldex and much to my surprise had to duck out of the way of a stream of fluid that poured out. Grabbed a cup and captured around 100ml of very cloudy, golden coloured fluid, a little more ended up on the ground and on me.

Fluid should not be coming out of the Haldex filler when the vehicle is level, let alone when it's rear end where the filler is is higher than the front. What came out is slightly golden, very cloudy, possibly slightly emulsified, smells a bit burnt but also smells of diff oil.

Clearly diff oil has found it's way into the Haldex

Garage coming to pick the car up at the weekend. Very fed up now, it was almost a month ago when I took it in to have the diff pinion bearing done and I raised the issue of the dripping, which I suspected was coming from the drain between the diff and Haldex the very first time it went back. The garage even initially told me that the issue was the seal between the diff and Haldex, but then changed their minds, said it wasn't the seal, just spilled fluid. It's generally accepted that once the clutch pack gets contaminated with oil it's toast.

It explains all of the symptoms, the screeches and bangs are I suspect the clutches slipping when they shouldn't.The fault wasn't apparent when I first picked the car up because at that point the oils hadn't mixed. The thuds at 25 mph are probably where the Haldex should be releasing smoothly but isn't. I suspect then the Haldex clutch plates are getting hot and perhaps no longer holding after the first mile (the oils smells burnt).

Almost 1 month now without the proper use of my car, what is probably now a next to scrap haldex, potentially damage to the diff and pinion if that's had haldex fluid in it, possibly damage or additional wear to the PTU splines too.

Which comes back to the original question - my Haldex failure was not merely a coincidence.

so glad you found the root cause.

Just goes to prove that I talk B ks from time to time.

Good luck with the garage, hope they put their hands up and admit that they were wrong. Tangiers Orange - gone, missing her
Replaced by Ewok what a mistake - now a happy Disco Sport owner