Hiding in plain sight
Over the last couple of months when out and about in the 1988 Jaguar XJ40 Sovereign, I had noticed an occasional metallic squeak when the car went over a bump. The first thing I thought of was a broken exhaust mounting which might be allowing a silencer to move against another part of the underside of the car. However, even though I had jacked the car up, put it on stands and lain underneath several times, I had failed to discover anything out of place. Everything just looked exactly as it should, and try as I might I simply could not see anything wrong.
Then a few weeks ago I had to take it along for its annual MoT. I reckoned that if there was anything wrong, it should show up during the inspection. Fortunately, it passed OK without any problems at all. However, I always like to take the opportunity of inspecting the chassis and underside of the car myself when I get the chance, so while the car was up on a ramp, I looked it over slowly and carefully.
Even though I had checked the silencer mountings previously and had not been able to find any problem, with the car now up in the air I was able to look over the complete system from the front all the way back with ease and in the light. I checked the exhaust yet again and nothing moved unduly, so initially everything appeared to be exactly as it should. But then, when I looked towards the front of the car where the exhaust passes the gearbox, I spotted the problem.
Between the torque converter casing and the bottom of the downpipe, just aft of where the two downpipes siamese into one, is a retaining bracket in the form of a flat metal strip. Probably due to metal fatigue over 34 years of vibration, the strip had fractured next to the bolt hole where it is secured to the aluminium casing. Clearly there would be hardly any movement here apart from when the suspension was compressed as the car negotiated a bump. The break was straight and clean, and when the car was parked with the engine switched off, the two ends of the metal were positioned perfectly next to each other so that the fracture was almost invisible.
Once I got back home, I called the usual Jaguar spares specialists to order a new bracket. The problem was that nobody had one, and they all said that the bracket was no longer available. No problem I thought, I shall simply have to find a secondhand one. After several more phone calls and still no luck in locating said
“The first thing I thought of was a broken exhaust mounting”
bracket, it looked like the only option left was to repair the damaged one on my car.
The following week I drove carefully over to Rob Allford’s place near St Albans and parked the XJ40 over the pit in his garage. The retaining bolts at each end of the bracket were in good condition and not seized, so they released easily enough. Once both pieces of the bracket were off the car, they were cleaned and de- greased in readiness for welding.
The two parts of the metal strip were then secured in position with lock- grip pliers before being tacked together with weld. Once that had cooled a little, I could remove the clamp and gain access to the full length of the break. With the bracket back in one piece, it could have then been refitted. However, Rob very sensibly suggested that it might be a good idea to take a second strip of metal and weld it to the original one for extra strength. Even though the original strap had been in situ without a problem for the last 34 years, since the original part was now unavailable this seemed like a good plan.
Rob happened to have a suitable strip of metal complete with a bolt hole in the end, so we located the bolt hole over that of the original bracket and then proceeded to weld the new metal strip over the repaired section of the original. Then the welds were ground back until the repaired bracket looked appropriately flat and straight. The finished strip might not look like a pristine new component, but it is almost certainly far stronger.
Refitting was hardly rocket science, simply a matter of doing up a mounting bolt at each end and it went without a hitch. The next thing to do was to take the car out on test. After driving along a road full of pot-holes, I then took it down a road with several sleeping policemen. The Jaguar took this unjust punishment to its suspension in its stride without a murmur, simply gliding silently over every rut and bump. Job done and with any luck it won’t need to be done again for another 34 years.