I'm getting a bit lost in the minutia of differentials. I have a new-to-me '03 X308 VDP with a paltry 30,000 miles. There was no discernible noise the test drive of 100 miles, or driving back 125 miles from the purchase point.

But, in recent days, I've started hearing a low-frequency whine/hum when the accelerator is pushed at speeds around or above 50 mph. The noise disappears as the throttle is removed. At steady state cruise the noise comes and goes. As one goes faster, the volume increases but the frequency of the noise is unchanged (Hz, not regularity).

At the urging of some I had the U-joints lubed, but that appears to have had no impact.

A) anyone know the likely cause/repair of this noise and B) I read a very long thread that talked about which Jags have which differentials, but darned if I can figure out what diff is in my car. Anyone know?

Thanks in advance for any guidance folks care to offer.

 

Does the noise/vibration change as the vehicle goes around a bend in the road or a corner?

 

Also, what is the condition and age of the tyres? You can tell how old they are by the DOT numbering on the sidewall. For example: DOT 2210, which means the tyre was manufactured during the twenty second week of 2010.

If the tyres are five or more years old, they should be replaced to maintain safe operation and ride quality.

 

Thanks for responding. One tire is mid 2016, the others mid 2017. (The spare is mid 2001!).

There is no vibration, just the low-frequency hum that begins at about 50 under acceleration and increases in volume with speed and drops off to nearly imperceptible when I lift the throttle. I have not tried listening in corners yet but will do that. I’m just dreading the thought of a differential on a 30k mile car I just bought! I guess one step is to change the diff fluid to see if that affects the situation.

I had a bad wheel bearing on a ‘97 X300L I owned a few years back and I know that growl/roar ... or at least would hope I would recognize it again.

Eliot

 

Thanks for responding. One tire is mid 2016, the others mid 2017. (The spare is mid 2001!).


There is no vibration, just the low-frequency hum that begins at about 50 under acceleration and increases in volume with speed. I’ve not tried listening in corners yet but will do that. I’m just dreading the thought of a differential on a 30k mile car I just bought! I guess one step is to change the diff fluid to see if that affects the situation.


I had a bad wheel bearing on a ‘97 X300L I owned a few years back and I know that growl, or at least would hope I would recognize it again.


Eliot

 

Having went down this road/saga recently, I went through wheel bearings,rear differential fluid grade changes,suspension components, & so forth. My hum/whine was a combo deal of faulty rear wheel bearings & compromised differential oil. But the knock & creak ended up being an obscure bearing on the rear end. It puzzled a couple of inept shops but it's finally sorted after a lot of misery inflicted lol. It was a process of elimination for me.

 

Not sure if this is your problem, but I had a similar noise on my 99 XJ8... sounded like it was rear axle related... replaced rear wheel bearings, still noisy... found a complete junkyard IRS and swapped, still noisy... researched the ZF transmission on a Mercedes forum and discovered that if the ATF gets bad, the TCC can "hunt" for lockup and cause a low frequency vibration or hum until it either opens or locks. Changed the ATF and the noise went away.

 

Thanks to King Charles and Mglagleder for avenues to pursue. When I had the vehicle checked out by an indy mechanic prior to purchase (30k miles, barely broken in but 18 years since manufacture and 17 model years) he pronounced the transmission fluid very fresh. But, that doesn't mean there's not an issue there.

There are two Jag-only shops in my region behind the three dealer operations and one Brit-only repair/restore shop I can go to beyond the very talented fellow at my local gas station who has maintained all my jags over the years and is familiar with ford/jag commonality issues as he has encountered others in a Lincoln he drives.

I'm thinking maybe a good course would be to pay one of the two indy Jag shops a diagnostic fee to get a reasonably well educated bead on what they think the issue/remedy is. (I don't have a garage in which to work so I generally hire out most things.)

Onward toward finding and fixing the cause, and thank you very much for respnding.

eliot

 

I used Top-Line Jaguar in Springfield a few times when I was in DC. Very good shop and they will pick you up from the Metro.

 

Mark: Thanks. I was actually thinking of Top-Line as I live 15 miles away in Annandale, or the guys over at Master Auto in Rockville (Jag techs who set up shop after living the Manhattan dealership.) Both have done things for me on rare occasion. Just FYI, I'm not sure how long you may have been gone from the DC area but there's now a Costco on the road that leads up to Top-Line. I'm nowhere near a Metro but I recall at one point I got a flyer under my wiper touting that they would come pick up your car and deliver it home,

Eliot

 

Yea, no Metro in Annandale; sounds like the pick-up-and-deliver would work, if you go with Top Line. Master Auto sounds interesting as I used Manhattan Jag when I was there from '01 to '06 and just starting my Jaguar experiences with an '88 XJ6, then a '98 XJR after my daughter totaled the XJ40. I was in NW DC at that time and Manhattan always did good work. Went back to DC in '12, but this time I was downtown in an apartment, so used Manhattan again for a few things. I left in November of '15, and that's when I used Top Line to do some suspension work. I had broken the front lower ball joints and bent some wheels hitting pot holes. Imagine that !!! Back again in October of '18 for a year as a contractor, but didn't bring the car this time (only the golf clubs) cause I didn't want to register it in VA, pay the city taxes, and parking in another apartment building; this time in Crystal City. So, without a car I didn't go any further South than King St, or North of Gallery Place/China Town. Metro in, cab home ... LOL

 

Mark: I worked in Rockville right at the White Flint Metro for 12 years before retiring (horrible commute from Annandale), so Master was a short walk away. My go-to guy, Jesse Bogan, was a few blocks from them. Sadly, Jesse lost his lease and isn't taking on much at the moment while he looks for a new property. I have used Rosenthal out in Tysons with pleasant success, treated well, got a free loaner. My concern here is being told I need a rebuilt/remanned differential when what I really need is a bearing or two replaced! I'm sure you're familiar with that fear.

Cheers.

 

the description sounds very much like what was the issue with my roadmaster wagon - because it seems accelerator related and not tire. If it was the tires, it'd be there constantly at whatever speed. I had bought the wagon at 78K and although i can't be 100% certain - went' by my mechanic's diagnosis - 80K later, it's still the same sound. A noisy pinion gear in the diff. I know this is a GM drivetrain, but isn't the 03 technically a ford drivetrain? Regardless, it could be a nonissue from a reliability standpoint- just an audio annoyance that you eventually forget most of the time.

 

Just to be clear, the X308 does not have a 'ford drivetrain'.

The AJ-V8 is a 'clean sheet' Jaguar design while the gearbox is a ZF 5HP24 and the differential is a Salisbury design 15HU built by GKN.

 

Eliot: Commute from Annandale to Rockville, I'm sorry !!! LOL I worked downtown at 7th and Independence, across the street from the Air & Space Museum, so my commutes were somewhat easier. And, yes, I've had that whining differential problem. I was in Sacramento then (Between the '06 and '12 time that I was in DC), so I took it to the one dealer in town to have them check it out. Got the call that I needed a new diff for $3400. I told the Service Rep that I would get back to him, then made a few calls. I found one that a parts contact had bought as a test case, but it was missing a part in the flange area. $200 for that, and $400 to have it over-nighted to the dealer. The day after the dealer got it, they had the diff installed, but called to say that the flange wouldn't torque down 'cause the cone washer was missing, and what did I want to do? Well, how about taking the cone washer from the diff that you took out? They called an hour later that my car was ready. So got out of that one for $1700, instead of $4500 !!! No problems since.

 

Wow, you really got out of that Jag malady well. Very creative. I am impressed. Maybe I should just preemptively lay in a rebuilt or remanned unit for the day the noise becomes absolutely unbearable.

As for my commute, my employer made it worth my while. And I’m familiar with 7th & Independence. I spent 4.5 years at the Friendly Aviation Asylum at 8th & Indy, and often sat in for the boss at A&S board meetings. I’m guessing you were either FAA or DoEd.

 

Yea, that was a lucky find on the differential. And, the $1100 in labor was worth it as I didn't feel comfortable changing that rock by myself with only a floor jack. But that dealer was expensive for parts. Before I got into why the throttle bodies go bad, I had the car there for a new one and they wanted $2400. Pulled the same trick by ordering one from Gaudin Jag in Las Vegas for $1600 and had it over-nighted. When I told them what I paid, the Service Rep said that they couldn't get one for that price. And, yes, it wouldn't hurt to start shopping around for a replacement before you get the big whine from the back.

You guessed correctly: FAA, on the Air Traffic side. And, it appears that they're having trouble filling positions these days as I got a few calls during the week asking if I would be interested in doing a part-time gig working remotely. Well, yea, that sounds interesting. When I left DC in November of '15, I had cut a deal to work from home; three weeks here, then one in DC. That lasted until April of '17, and I wrote the second version of the Wake Turbulence Recategorization Orders sitting at my desk in comfortable clothing looking at the Eastern Slope of the Sierra Nevada Mountains. By the way, thanks for that pay raise back in '99 !!!

 

Mark: On behalf of Jane, you're welcome. I was APA-1 (now AOC) from mid-'96 to Jan. 2001, hanging out in 908 of the main building. I suspect we know many folks in common, like Monte, Ron Morgan, Dave Canoles etc.

Eliot

 

Eliot, before you do anything else to try and pinpoint the noise or let a shop work on it, I need you to do something. When driving and you get it up to 50+ mph and the noise starts up, shift the gear selector from “D” to “4”. Do not lift up or press down any harder on the gas pedal, just maintain the same throttle angle prior to moving the gearshift from D to 4. What this does is unlock the torque converter and downshift the transmission to 4th gear. Does the noise in fact go away? If it does, thank “mglagleder”. It’s been about 1.5 years since this happened but, I had a customers 02 XJ8 with a similar noise in the” rearend”. Nevermind the low miles. Your car has, lthe old ATF. The fluid may even appear ok just like you already mentioned but you still don’t know the cause unless that the TC is unlocked

 

Ok, I’ll give that a try. Meantime I’m searching for whatever post from mglagleder references this. So far no joy, but I suspect I can find it eventually. I’ll report back once I’ve done the suggested test.