World of Hurt! Rear Diff 94 Sovereign

(Sean O'Donoghue) #1

It’s a long story. Maybe I’ll tell it later. But what is going on with my Salisbury 4U? Have my bearings crushed and the axle stub moved further into the diff? Have a look at the pictures and share your thoughts.!


(Sean O'Donoghue) #2

Note in these pictures, #1, #3 and #4 are the drivers side output shaft, where the problem is, picture #2 is the passenger side, with the leaky seal, where the problem likely began.

(Robin O'Connor) #3

I think that you must have quite a bit of movement in the 6 - 12 o’clock position? If so then there’s your answer, bearings shot.

(Bryan N) #4

As Robin said, it is easy to determine if the output shaft bearings have collapsed by the excessive movement in the vertical plane of the wheel since the half-shaft is the suspension upper control arm - and negative camber of the back wheels would become apparent.

However, looking at your photos 1, 3 and 4 (a Canadian car so presumably LHD?), isn’t there something missing from the joint between the output flange and the half-shaft? Shouldn’t there be the castellated speed sensor on the left side only - or do they measure road speed differently on the '94s?

(Dick Maury) #5

Axle bearing shot in the axle assembly. Easily replaceable as a unit without pulling the diff. The later cars did not use the external stator wheel for road speed. Make sure you get new/used bolts when replacing and make sure you save and reuse the spacing shims located right inside the diff housing.

(John Quilter) #6

Just for my information, what’s the total mileage on the car?

(Sean O'Donoghue) #7

John, odo just turned 180,000km, so it’s a spring chicken.:rofl: I have owned it for about 4 years, an all season daily driver for me, though I am only responsible for 25,000km, including a 6000km road trip last summer.

(Sean O'Donoghue) #8

Thanks Dick, any idea where road speed is measured from in a 94? I will pull the bolts and replace, but is there anything special about them, can I source appropriate size grade 8’s?

(Sean O'Donoghue) #9

Robin and Bryan, indeed alot of negative camber, first thing I noticed at roadside. I don’t really get how the output shaft can cave in to the diff without damaging diff internals. I guess when I get into it I’ll understand better. Car is jacked up in my driveway, wheels off…now the wonderful head scratching begins.

( Larry ) #10

If all fails Sean, keep in mind I have a spare low mileage diff down here in jolly old (heavy bugger tho)

(Sean O'Donoghue) #11

Thanks Larry, your low mileage Salisbury, stored in a rubbermaid tote, was the second thing I thought of while I was grappling with the predicament of catastrophically crunching sounds coming from the rear end of the Sovereign on a little turnaround on the Kitimat Highway during an off island family holiday, with the prospect of a slow shoulder drive 40 km back to Terrace for quick diagnoses, a one and a half hour flatdeck tow (Crew Cab rig fit the family) along the Skeena River on The Yellowhead Highway (#16) to Prince Rupert, a 7 hour overnight ferry ride to Haida Gwaii and a 2.5 hour 80 km drive home, just so I could assess the damage in my own driveway. The thought of your low mileage Salisbury gave me much comfort and solace along the way.

( Larry ) #12

Well let’s hope it can stay sleeping in the tote …:zzz:

(Bryan N) #13

From memory (at last recalled!) I believe road speed is determined via the ABS sensor(s) on the later cars.

(Dick Maury) #14

Standard metric bolts. I have plenty of good used but probably cost less at hardware store than shipping costs. Speed pickup is on the aluminum diff cover.

(Bryan N) #15


That was certainly true on the early XJ40s (like my '91) but are you sure that still applies to the '93 / '94 models which dispensed with the speed sensor castellated device on the half shaft to diff output shaft joint in favour of the ABS sensors via the ABS ECU?

(Dick Maury) #16

Could be wrong as I have more experience on the earlier cars. Best I know, the ABS sensors are on each wheel for the ABS system. . The speed sensor which works the speedometer and cruise control mounts on the aluminum diff cover and picks up via a stator wheel inside the diff. This ran through the end of the X300 cars.

(Bryan N) #17


Out of curiosity I have now checked the circuit diagrams and whereas on the cars up to the 93 models it shows the road speed feed to the speedometer being directly from the speed sensor on the diff which you describe, the 93/94 models show the road speed feed from the ABS ECU being sensed by the ABS speed sensors on the wheel(s)

(Dick Maury) #18

Good to know. In checking, the sensor on the rear diff cover is only on the XJS model with aluminum covers. The XJ6 did not have a sensor on the diff. So when the external stator wheel was deleted on the XJ, they must have switched to ABS sensor pickup for speedometer.

(Casso) #19

I’m surprised you didn’t notice a whining noise coming from the rear for at least a few thousand miles before that bearing collapsed like that, or maybe like myself you like to drive with the sound system cranked up :grinning: When the oil level in the diff drops it is those output bearings that suffer first, they have a hard enough life even when properly lubricated.
When I changed them on my 94, a service exchange complete output hub assembly was readily available in UK, and the price was only a few quid more than a bearing kit. It made the job real straightforward, a case of unbolt the old unit and fit the new one in place. No need for a hydraulic press etc. Some of the bolts that hold the output hub to the diff can be awkward to get at, and they can be very tight, so if you are planning on doing the work yourself I’d recommend you use a really good fitting socket to avoid slipping and rounding the heads, it looks like quite a chunk has been rubbed away already in the pics.
Good luck I hope it all goes well.

(Robin O'Connor) #20

Make sure you use a six point impact socket NOT 12 point, especially with the state of what’s left of the bolt heads.