Jaguar Forum banner
1 - 13 of 13 Posts

·
Registered
Joined
·
19 Posts
Discussion Starter · #1 ·
Hi everyone,

Didnt know whether to post this in engine or suspension forum as thats part of my question.

I recently bought a high mileage XFR (110k miles). It has an annoying driveline thump/clunk when accelerating or letting off, even normal driving. I can feel it in the floor of the car.

From my experience with mustangs I suspect diff bushings or maybe the driveshaft. The guibo and trans mount look pretty new (not 110k miles).

Anyone else ever experienced this? Before I start throwing parts at it.

Thanks,

Nick
 

·
Registered
Joined
·
6,660 Posts
Diffs are the normal culprits, but they whine normally. Need to eliminate the propshaft.
 

·
Registered
Joined
·
19 Posts
Discussion Starter · #3 ·
I wonder if anyone with higher miles ever replaced the rubber diff mounts? They are available as separate items and normally wear on other rwd cars.

I dont think its the diff internals, the ring and pinion backlash would occur from standstill, not getting on and off gas, that keeps the gears still spinning in the same direction.
 

·
Administrator
Joined
·
30,260 Posts
Not engine or gearbox mounts? I would have a good look at the rear gearbox X member and its mounts.
 

·
Registered
Joined
·
85 Posts
I have the same thing and have narrowed it down to drive shafts... maybe lol. Over the past 4yrs I have replaced all susspension bushes, prop shaft and doughnut , had a low mileage trans fitted ( due to other issues) and a diff and still have the knock sound. All the mounts have been check but play in the drive shafts has been noted. I love my Xfr but it’s cost me a fortune 😃
 

·
Registered
Joined
·
8 Posts
There is another possibility. Does this occur all the time or only with a full fuel tank? When I have a full tank I get a fairly loud thud on accel/decel as the fuel slushes back and forth and the tank hits the car body.

I believe there is an official fix for this where absorbent foam is fed into the tank to damp the fuel.
 

·
Registered
Joined
·
19 Posts
Discussion Starter · #7 ·
I have the same thing and have narrowed it down to drive shafts... maybe lol. Over the past 4yrs I have replaced all susspension bushes, prop shaft and doughnut , had a low mileage trans fitted ( due to other issues) and a diff and still have the knock sound. All the mounts have been check but play in the drive shafts has been noted. I love my Xfr but it’s cost me a fortune 😃
That's not very hopeful :LOL::LOL:
I'm used to a little agriculturalness in mustangs, but in a jag it's annoying.

Tank is half full atm, but it def feel like something solid thumping about.
 

·
Registered
Joined
·
1 Posts
I have 2012 XFR with 68k miles. That clunk was present from around 35k miles.
Changed that donut coupler (guibo), both half-shafts (brand new), oils in gearbox and diff, no difference. Rear suspension is serviced - no difference, the clunk is still present. Only 3 things left: gearbox rear mount, rear diff bushings and prop shaft itself. It is impossible to recreate that clunk when car wheels are not on the ground.
Also, I forgot about the rear diff - I think it could be also the source of that nasty clunk
 

·
Registered
Joined
·
19 Posts
Discussion Starter · #9 ·
Im no mechanic, but I dont see how the ring and pinion gear could cause a clunk when youre still moving in a forward motion. From reverse to forward, yes.

The diff bushings came to mind because of my experience with the IRS in the mustang cobra, but they should not have been worn enough in your XFR at 35k miles...

Such a mystery this.
 

·
Registered
Joined
·
19 Posts
Discussion Starter · #10 ·

Most websites I googled note that a clunk off/on acceleration is not related to the gears, but more likely driveshaft or diff bushings/bracing
 

·
Administrator
Joined
·
30,260 Posts
Diff clunks can also be down to excess end float on the planet gears.
 

·
Super Moderator
Joined
·
31,067 Posts
Knowing that the diff is one of the weak links with the XFR/R-S, it would always be my first thought.
 

·
Registered
Joined
·
22,319 Posts
Some time ago I experienced a clunk from the underside of my XF (not an "R"). Fortunately, it was still under warranty and although I would have sworn it was a transmission clunk, turned out to be . . . . the front, off-side shock-absorber. Was clunking as it loaded and unloaded under acceleration and deceleration.
Just a thought.
 
  • Like
Reactions: Gav
1 - 13 of 13 Posts
Top