Part 16 - Per Ardua Ad Infinitum 2022 - Postscript

The XJ-S had survived its greatest rally test so far:  1000 miles over one long weekend, with 300 competitive rallying miles including 14 regularities and 17 tests.  

The HERO film above gives you a flavour of what was involved (we're interviewed at about 10:28).

Nevertheless, by the time we got home, not all was well.  

Mike Ferrari at our ever-helpful local Jaguar specialist, Epping Classic Cars, agreed to put the car up on one of their lifts so I could inspect the damage.  Our family has been customers for over 20 years and we are happy to unashamedly give them a mention! 

As long standing Jaguar and Land Rover specialists, Mike & Ian cast their expert eyes over the car, giving me a tip here and there, as I carried out my own inspection.  There was good and bad news:

The bad news was that the one-year-old rear radius arm bushes were already very much past their best, in fact, one of the metal inserts had torn itself out of the rubber bush, such was the abuse it had suffered.  

That bush is toast!

A long discussion followed about the merits or otherwise of polyurethane replacements.  

Before embarking on this project, I had a conversation about car preparation with Ed Abbott, who campaigns the only other XJ-S in historic regularity rallying (that I know of).  Ed was one of the original development engineers involved with the the XJ-S, so I paid attention to what he said!  Even so, I was surprised that his (entirely rally optimised) XJ-S was equipped with the standard rubber suspension bushes.

Who am I do disagree?  Long ago, I realised that the driver is nearly always the weakest link in the car/pilot combination, so improvements in that area are worth so much more than trying to out-think the car's engineers.  

So, after some more advice via 'phone from Polybush (polyurethane bush makers, obviously), I decided that sticking with the original softer bushes would be a better route than upgrading to hard race-specification replacements.

In any case, I have long favoured Jaguar's classic approach of softish springs combined with firm dampers:  It might not give ultimate handling, but together with the long travel of the Jaguar's suspension, combined with fairly high profile tyres, this set-up ensures the wheels stay firmly in touch with the ground, regardless of the terrain - something that proved itself invaluable on the rough, rain-soaked PAAI.  

By way of contrast, my slightly more modern, more powerful, and faster 2002 Jaguar XKR hops and skips over ridges and bumps on its factory uprated & lowered suspension and wide ultra-low profile tyres, triggering the traction control far too early.  Yes, it is ultimately much faster than the XJ-S (the grunt from the XKR's supercharged engine is addictive) and very grippy in the dry, but at lowish speeds, it lacks the fluidity of the XJ-S.  It is only at (very) high speed where the XKR comes into its own, feeling tied down to the road, where the XJ-S starts to show its age.

Since most of regularity rallying is at no more than 30mph, we'll stick with fluidity!

Back to the damage report...

Apart from a creased silencer box and a small hole in one exhaust pipe, the rest of the car hadn't suffered too much.

The shocking state of the roads on Sedgemoor Flood Plain
 were not kind to the exhaust system

The good news was that, despite the liberal coating of Somerset mud, Mike & Ian commented this was one of the most oil tight XJ-S V12s they had ever come across....a generous film of oil, blown back from the engine lubricates the floorpan on most other examples!

If you are a Jaguar fan, there is always something interesting to see at Epping Classic Cars:  They usually have two or three E-Types of various specifications in for servicing or restoration.  You can see V12 engines striped down, rear axles being refurbished, gearboxes being overhauled...in fact they are happy to tackle everything mechanical and electrical.

Epping Classic Cars Busy Workshop - Modern Jaguars and Land Rovers
as well as Classic Jaguars.

A Series III E-Type undergoing restoration

There is always a list of work to be done on the XJ-S, in addition to the regular servicing the car requires. We have about six weeks before the next event, so it's time to get on with its urgent needs.

It is well known that the rear axle cage tends to flex under hard use, which I thought might have contributed to the early failure of the radius arm bushes.  In addition to a sump guard, I have plans to fabricate a skid plate/rear cage brace to protect the differential, so whilst the car was up on the ramp, I took a myriad of measurements for the design.  

We might end up removing and modifying the steel sump guard currently fitted to the old Ford Focus (see Part 13) instead of creating one from scratch; however, the rear bace/skid plate will have to be custom made.

Most of the exhaust clamps needed replacing, having been bent and busted by frequent contact with the tarmac and rocks on the PAAI. I would use low profile stainless steel clamps that will give us just a little extra ground clearance, but as I have a box of U-clamps, they'll have to do for now.

The paint on the sills has been almost entirely chipped away by the gravel thrown up by the wheels.  The surface rust needs treating before it becomes a problem.  That's one on the bodywork list (rust never sleeps...) for a bit later in the year.  The amount of the salt on the roads this winter has turned anything slightly susceptible under the car a horrid shade of rust.

Whilst underneath the car, I removed both rear radius arms so that all four bushes could be replaced at the same time.  This revealed why the rear bush had failed so badly:  The front bush's steel safety strap on the same side had been bent and twisted so that, although the inner mounting of the large bush was sitting correctly on the body, the bush itself had been stretched two inches to the rear, moving the radius arm with it and tearing the rear bush.

One of these safety straps is bent!

The front bush being pulled out of joint

Torn bushing and safety wire

I thought back to how that might have happened.  I'm fairly certain it was on a very sharp, very uphill hairpin bend at night on a single track road.  I felt the bottom of the sill sliding over the ground....and at the end of the sill lies the radius arm safety strap, which must have caught a rock or something similar.  You can see in the photographs above, the bent strap with the safety wire torn away.

The last time I replaced the bushes, Mike at Epping Classic cars advised me to buy new radius arms with the bushes already installed, as it is a lot less effort.  As the new radius arms have only been on the car for a few thousand miles, it seemed profligate to replace the perfectly good arms - I would have a go at replacing the bushes myself, saving several hundred pounds.  

Mike agreed I could use his industrial hydraulic press and very kindly supplied me with the correct Jaguar tooling (as I had no other way of doing it).  He said the tooling would perfectly fit the original Jaguar parts, but might not be quite right for the the replacement pattern pieces I had previously purchased (alliteration unintended).  And so it was...perhaps only 0.5mm out, but that 0.5mm made all the difference....those bushes weren't moving.  Mike, even more kindly, put the (rare & expensive) Jaguar tool on his lathe to reduce it to fit the pattern parts.  Several hours of further struggle passed and eventually the radius arms were resplendent with four new bushes.

Replacing the radius arms always feels slightly unorthodox, requiring the use of 2-tonne ratchet straps to pull the rear cage into the proper position, but an hour under the car saw everything back in its proper place.

A change of oil, new filters and a precautionary check of the front tracking and we were ready for our next adventure: 

I have roped in Dexter, my youngest son, as my navigator for this year's HERO Challenge.  His first test will be in the byways of North Wales on the HERO Challenge One 2022.