Upper rear suspension plate mod?

Hi guys, refugee from the XJ40 list here …

So I have a bit of an issue. I have a late 94 XJ40 with the hybrid X300 rear suspension - I say hybrid because the arms are cast and use the same shocks as the X300 lowdown, but retain the shock mounting plate design used on the earlier XJ40’s.
The plate is basically the same, but the X300 upper mounting plate has a bushing retaining ring added to the underside which holds the bushing centered preventing the shaft of the shock from migrating toward and banging into the aperture in the plate.
When I replace shocks, the bushings and collar/arrangements supplied with the new dampers work OK but eventually the bushing slides out of position and I get a bang bang over bumps etc.
So my plan is to weld a retaining ring to my top plates, but I’m not sure of the size …if anyone has one from an X300 on hand could you measure it - or failing that, is the upper bushing a snug fit in side that ring before bolting up? I’m guessing it is and if so perhaps I could just measure the bushing and create a ring same size?

TIA for any advice/opinions

I just happen to have my 2002 X308 apart for new rear shocks. The 308 uses a large diameter lower foam bushing and a smaller diameter upper bushing. The metal locating/retaining ring/“cup” is on the bottom side of the mounting plate. It is very slightly flared (cone shaped) with the opening diameter at about 2.7 inches and narrowing down to about 2.6 inches (the diameter of the lower rubber/foam isolator/bushing) where it meets the bottom side of the plate. So the upper surface of the lower rubber/foam bushing is snug against the mounting plate and the locator ring when inserted, and then expands/bulges into the very slightly cone shaped ring when the nut on the top of the shock is tightened. I think a ring with an inner diameter the same as the lower bushing would work fine. The depth of the steel ring is .53 inch. I can get you a photo of the bottom side of the mounting plate later today, or you might check on the Jaguar Forums site… XJ XJ8 / XJR ( X308 ) - Jaguar Forums - Jaguar Enthusiasts Forum

Here is the xj-40 section XJ40 ( XJ81 ) - Jaguar Forums - Jaguar Enthusiasts Forum

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Hey thanks a lot Eric, photo of plate top and bottom would be great if you can manage it …oh and what is the size of the hole? Other measurements are just what I was hoping for, thanks again!


The hole in the plate is 1.25". The smaller, upper bushing sits in the depression in the plate, and the bottom bushing is captured in the ring…no top hat bushing involved. I saw no evidence that the bushings/shock rod had migrated out of position. The issue with my car (40,000 miles) is that the large "donuts had disintegrated causing a metal to metal rattle over bumps. Requested PICS below…

BTW, I attempted to press out the factory spherical bushings at the bottom of the shocks (reusing the CATS units as they’re in good shape…and cost hundreds each to replace). Anyway, I couldn’t get the bushings to budge using a long, threaded rod and sleeves…so I’ll have to find a hydraulic press.

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Thanks a bunch Eric I’ll let you know how I get on - good luck with yours!