What Have I Done? Tales of a Jaguar XJS - Part 5
Thursday, 3 October 2019 | Admin
PART 5 - A STEP FORWARD
It is said that a journey of a 1000 miles starts with a single step. The problem is taking that initial pace forward. I had been putting off the mammoth task of replacing the rotten front subframe for some months, more in trepidation of what might follow than lack of time.
Eventually I could delay no more. The first job was to build a cradle to support the 1/2 ton engine and transmission to allow us to extract the front subframe complete with the steering rack and all the front suspension and brake components. Dire stories of injury and death surfaced from internet searches with warnings to use only the official Jaguar workshop equipment. Putting these worries to one side, I decided that four lengths of 4" x 4" timber, some custom made brackets and 4 x 2-tonne ratchet straps would be more than sufficient to hold a half-ton weight. Backed up with some sturdy supports under the transmission for extra security and after some hours struggling with nuts and bolts that had been untouched for 30 years, remarkably, the complete assembly glided slowly and steadily from under the body shell. We had taken the first step. Now we just had the remaining 1000 miles.
The next stage was to dismantle all the components from the subframe. I had read that removing the pivot rods from the front wishbones is the most difficult part of working on this model. I had two of them to deal with. However, before that was the thorny problem of removing the front coil springs. Of course there is an official Jaguar tool for this (as normal coil spring compressors don't fit), but finding one or hiring one is next to impossible. Turning once more to the internet, many suggestions can be found, nearly all of which actually do risk life and limb given the potential energy held in these heavy duty springs. Luckily I found a resourceful Canadian who described a method I found sensible and safe: Akin to an external metal brace around a complex fracture, the method carefully and slowly released the compressed spring using four high tensile steel rods and nuts until the spring pan could be safely removed. Slow and steady, but after some hours, ultimately successful. Luckily I'm not billing myself for my own time!
Now for the pivot rods: I knew I wanted to re-use the pivot rods, if at all possible, as they are no longer available from Jaguar. When new, they should slide in with a light tap from a hammer, but 30 years later that same light tap achieved nothing. After around four hours of increasing force and desperation nothing had moved - it was seized solid. A few days of liberal application of releasing fluid followed and eventually the first pivot rod was extracted in more or less a re-useable condition (although I was not that confident that it would be good enough). Another day of frustration followed attending to the second pivot rod, ending with the application of a very large sledgehammer to the offending rod. Extraction was successful, but the rod was unusable.
Many hours of cleaning and painting the suspension components followed over the next few days whilst I waited for a new pivot rod to arrive from a specialist. Re-assembly should be a relatively easy job - just like Meccano - so with everything ready, I set to work one Saturday afternoon, showing my eldest son how clever and quick I could be....until one small bracket did not fit...that's strange, perhaps I mixed up the left and right brackets when I was cleaning them. I re-traced the assembly steps and found to my dismay and embarrassment, that the very first component I had fitted was in fact the incorrect item....the wishbone secured with the pivot rod. No matter, I would simply disassemble and start again - a wasted afternoon, but no damage or extra cost. The left and right wishbones are mirror images of each other, however, the difference is quite small and in my hurry I had fitted the left hand wishbone to the right hand of the subframe and vice versa. Small the difference might be, but hugely significant when it comes to removing the pivot rods (again).
The slight change in angle of the wishbone meant both the old and the new pivot rods were stuck fast. Another wasted day ensued: No amount of force (including the very large sledgehammer) would move them. In my research I had dismissed advice from enthusiasts in the USA that the best way of dealing with the privot rod problem was simply to cut through each rod twice with a reciprocating saw. This would release the wishbone and the pivot rods in one go, albeit with the destruction of the pivot rod. This had seemed an unnecessary waste, but now seemed the only solution. I picked up a nice new reciprocating saw from my local tool company and within five minutes both wishbones had been removed. I doff my cap to the American owners....if I had not been so dismissive, I would have saved myself four days of sweat and toil.
I commissioned two more pivot rods from the specialist (having to wait a few weeks for a new batch to be manufactured). This time, assembly was slow, deliberate and successful. We had a fully restored subframe, refurbished front suspension, new front brakes and a steering rack ready to fit back into the body. The whole assembly went back into the body shell without further incident. The engine cradle removed, fluids were added, brakes bled and the car lowered onto its wheels for the first time in six months. She started on the button and everything looked rosy!
Next time: An Unexpected Journey