[QUOTE=Tervuren;1934279]Jaguar parts catalog shows only one differential for all US 2007 - 2009 X150 models (4.2L, NA and SC), part # C2C34880, MSRP $2,800. I don't know if there were older, superseded part numbers.

 

I would go for the newest model year of a well documented car that matches your color & option preference.

 

There are only really two gearboxes in the X150: 6HP26 in the 4.2 and 6HP28 in the 5.0. The 6HP28 changes faster, locks the torque converter sooner and can skip gears rather than changing sequentially.

Allegedly, the torque converter was uprated for the XKR 75 in 2010 and that was carried forward to the R-S, but that has been disputed on the basis that they all (apparently) have the same part numbers - there was a thread on this a few years back. One of the confusing factors is that ZF have options for each gearbox model that manufacturers can choose to suit their particular application. So the 6HP28 in the XK will probably be a bit different to one in a different vehicle, particularly a non-JLR model.

 

Hi Ngarara,

Thank you for that, I was aware of all of this, just hadn't heard the change in the middle of 2010 XK or XKR before and was curious what info was behind this statement.

FWIW, the info you posted is still great info for this thread and others, thanks again for that!

Cheers,

Dave

 

Also, the differential is the weak link to the cars. The later electronic posi versions eat themselves and the older non posi ones are a weak cheapened version of the venerable Ford 8.8" rear with an 8" ring gear and a single main bearing cap (the other side fits in a pocket) and not enough room in the housing to install most 8.8" posi units.

 

I haven't seen much talk of diff failures on the forum. Like the gearbox, it's probably prudent to change the oil at 60k miles or so, despite the 'sealed for life' claim.

 

Some batch of the early (Visteon) diffs have had issues, and might've been replaced with GKN diffs. See these threads for more information:
Overview of Jag differentials
Differential Noise

If you want to look under the car from the rear, here's how to tell the two diffs apart; basically colour and the "backplate" being on the side on the GKN diff.

 

Own a 2008 XKR convertible. This is the last year of production under Ford ownership. Ironically, it has been bulletproof. Only minor fixes and regular maintenance (oil, brakes, etc.). I also own many Fords and the Jag has had fewer problems. Currently selling, not due to problems, but want to explore some other high line/exotics. So, 2008 was a good year in my experience.

 

Hi Ranchero,

So just how many have you broken? :-)

Can you please direct me to the threads or info about the later Active Diffs "eating themselves". I haven't come across those threads yet. Would like to know if there are things I should or shouldn't do to keep mine from doing the same.

Thanks in advance and have a great evening,

Dave

 

 

[QUOTE=Stuart S;1934318]According to JEPC the change point was from VIN B19550 which is just prior to the 2008MY (B20075).

 

I haven't broken any but my early one is on the way out. Same diff was used on 2nd gen Lincoln LS's which I had for a couple years. Good many conversations on the lincoln vs cadillac forum over the last couple years. Largest problem is the housing is too tight to fit a conventional posi and a Quaiffe unit is the only direct replacement. I'm going to try and use a 1st gen LS unit which is wider and offset as well as using different length half shafts so it can still center the driveshaft. The 1st gen will use a conventional 8.8" posi and larger more robust gearset. I'm pretty sure we are stuck with 28 spline shafts though.

The E-diffs have had trouble which seems to result in replacement versus repair according to dealer results. If it gets noisy it's dead. Good many threads on the forum once you rummage around a while, especially on the F type side.

 

We might be confusing the author of this thread
The 5.0 engines were supplied with an electronic diff with clutches...as you are aware those can wear, however only when the fluid isnt changed in time and with spirited driving.
Which goes right back to ensuring you get it from someone who looked after it, or simply build in a buffer in the price for incidentals.
Again, there are no bang your head on the wall moments.

 

Other things that are a PITA and will come up as the cars age...

Headlamp housing wiring gets brittle over time caused a couple aim failures on mine. Not really a maintenance issue since the ozone from the HID bulbs seems to be the culprit.

Garbage suspension joint booties that crack and gave the dealers and MOT inspectors lots of easy money.

Lets not forget the pitfalls of a weak or aged battery.

5.0's also seem to have that thing with the injector staying open which is a BUMMER.

Driving the car in winter weather will give grief as soon as the windows freeze to the doors and the down position limit is now all the way up because overloading the window motor is how Jaguar decided where the up and down limits are. Hard on the roof lip seal. Only practical way to reset it is to unhook the battery for a minute.

Absolute PITA to change the blower oil on the 4.2 //R's

Add in another PITA to deal with the plastic coolant parts that randomly fail from heat cycles and coolant mismatch.

XK 4.2's have the garbage plastic T-stat housing that fails. Both are afflicted with a T stat design that has the rubber seal fail causing cooling problems.

Never forget no temp monitoring on either 4.2 or 5.0 and 5.0's have the bane of an electronic dipstick.

Wheel bearings seizing in the bores due to too tight of a fitment was another PITA to remedy. Just poor engineering there.

Finally for this short list is the absolute crap thin metal vanity cover on the lug nuts that will strip out at the worst possible time leaving you cussing on the side of the road.

 

Ranch I'm a bit surprised here about your claims. I would think with your background that you would want to see data other then a few posts on this site. The items listed may have been a few issues to a few members of this board but so far I haven't seen any significant data on failure rates. In fact I believe there has been several articles listing the top cars with poor reliability and Jaguar didn't make the list. So you got me here . Point me to the data and I'll be a believer.

 

Yeah you sound like ranchero84 not ranchero50.
The lugnuts kinda gave you away- No one in UK will ever have a problem with those lug nuts, and why they have been on Jaguars forever.
You left out an actual problem, leather on dashboard shrinking, again not one reported case in UK.

 

You might be adding to the confusion because the author of the thread said 2010 XK and those don't have the e diff

 

It's just a compilation of actual problems I've documented in my rebuild thread and other topics of discussion on this forum since I've joined. All of it can be verified, even the shrinking dash leather that I forgot. It is what it is. Use the vehicle and things fail as they age. Most failures are design related.

 

I do not see what there might be to be grumpity about the list, it is made up of real issues people have encountered.

As time wears on there will be these issues across a greater number of owners.

Three months shy of three years for me.

 

Terv it's not that some of these things didn't happen it's just about how much of an issue they are. It doesn't even point to any significant trends. Think about it as how many XK's and XKR's have been built. How many 4.2 and 5.0 L motors have been built. Now out of the thousands or hundreds of thousands of them we have seen maybe 10 people on this form identify they have had the problem. In my prior life in the semi-conductor mfg. world we always worked on data and trends during the mfg. process. The difficult part here is being able to get the data. In one survey I see Jaguar is listed as the 17th most reliable vehicle. Should we watch out for these issues , yes but they shouldn't be a deterrent from buying one. I must say when I looked at several of these surveys I found the Audi A4 came up in the top 10 most reliable . On the Audi site the biggest complaint is their 2.0L oil consumption. They even lost a class action suit and had to replace rings and pistons on a large amount of cars. That's a trend but the OM stated that 1 L. of oil consumption per 1200 miles is acceptable.