We follow North Wales Jag Centre replacing the rear subframe on an X350-generation XJ
WORDS & PHOTOGRAPHY ROB HAWKINS
IT MAY have an aluminium body, but the X350 generation of the XJ saloon doesn’t completely escape the problem of corrosion and sadly follows the reputation of its predecessors when it comes to the subframes.
We followed a front subframe being replaced in the November 2022 issue and this time, we’re following a rear subframe being replaced on an XJ Super V8 model belonging to Ben Willcox of JagDroid.
Ben had unfortunately discovered how corroded his rear subframe was when his Jaguar failed the MoT test. Fortunately, North Wales Jag Centre saved the day by fitting a second-hand replacement subframe for him and, after bleeding the brakes, setting the handbrake and checking the suspension geometry, the car is now back on the road and fast approaching 250,000 miles.
Here’s the rear subframe on a 2004 XJ that needs to be replaced for an MoT due to corrosion. The used replacement is in the workshop at NWJC, ready and waiting to be fitted The job starts by spraying penetrating fluid over the mounting bolts, then Paul at NWJC attempts to undo the three 10mm frontmost bolts for the two support beams for the subframe The rear brakes need to be removed, so Paul starts with the separate handbrake calipers, followed by the footbrake calipers (both fitted with two 13mm bolts) and then the brake disc Several suspension components are detached from the wheel hub, starting with the lower arm’s outer mount (18mm nut and 21mm bolt) and the track control arm (13mm nut and 15mm bolt) After detaching the ABS sensor, Paul tries to undo the 18mm nut (19mm in our case) for the nearside rear upper wishbone’s outer ball-joint. The stud spins on the final turns, so he holds the top of the ball-joint with vice grips Applying heat from a blowtorch helps to release the nuts on the ends of the ball-joints for the upper wishbones. The heat allows the nut to expand and if it’s a locking nut, it melts the nylon inside The wheel hub and driveshaft can now be removed together, so armed with a pry bar, Paul separates the end of the driveshaft from the differential. He extracts each assembly out through the wheelarch After undoing the 21mm mounting bolts securing the bottom of each suspension damper to the lower arm, Paul turns his attenti
