GOING NUTS WITH SHOCK ABSORBERS

The warm weather has suddenly arrived. I've started getting up 
earlier, probably in the main because the birds living in the 
bushes outside my window have been waking up earlier too, chirping 
loudly over each other in a chaotic morning chorus. Yesterday was a 
public holiday so I got stuck into working on the Jag early before 
the heat set in, to follow up my now routine weekend blitz. But if 
I start on that today I'll never stop for work because there is 
always just one more step to do, so instead I'll write a little 
summary here.

The great news is that with that new bearing (see 
2023-10-25Bearings_and_Bare_Bums.txt) in the diff, the nasty noises 
from the rear of the car when travelling at high speeds have gone 
entirely. So that's the main problem solved. The rear shock 
absorbers were replaced and I didn't suffer any exploding spring 
issues with the spring compressor, although it turned out the 
springs were 1mm thicker than the maximum rating printed on the 
box. Really I'm too much of a wimp with compresed springs and half 
my trouble was with reassembling the first one because I didn't 
dare to compress them enough to get all the new, unsquashed, 
bushings in place. The top of the shock absorber shaft had also 
worn an impressive notch through the top mounting plate by rubbing 
after the bushing the centres it had worn away. Luckilly after a 
while trying to figure out how to make a big washer to fit in the 
recess and support the shaft at the gap, I eventually discovered 
that a 1-1/4" washer was the perfect fit, and about the same steel 
thickness as the mounting plate too. Then I cut some bits off the 
old bushing to stuff into the small gap, which then all jumped out 
again during reasembly more times than I care to mention. By the 
time I did the one on the other side (with a much smaller notch, 
but I gave it the same treatment anyway), I'd figured out that I 
could cheat by super-gluing the bits of rubber bushing together 
first.

I kept thinking that I must be doing something wrong needing to 
lever the bottom of the rear shock absorber into place with a huge 
screwdriver, at great risk of hands slipping rapidly into blunt 
objects, but after an hour messing around with different 
orientations for the second one, I concluded that really must be 
the only way to do it. I guess it's straight when it's on the 
vehicle with the weight on them, so you could use the spring 
compressors, but they scare me to much and undoing them in the 
wheel well would be very awkward. Or maybe I'd just hit my head 
against that wheel well so many times that I was senseless by that 
point.

I certainly wasn't sensible enough to savour my success and drive 
the car for a bit, because last weekend I dived straight on into 
the front shock absorbers. With these I just wanted to replace the 
bushings to cure knocking sounds when going over rough surfaces 
(ie. about the first 3Km+ of anywhere from my house). This would 
have been pretty easy if I'd gone the normal route and just changed 
the top bushings, but determined to eliminate as many potential 
sources of nasty noises as possible, I decided to do the lower 
bushings too. Unususally these are pressed in to the suspension arm 
instead of being part of the shock absorbers themselves as on the 
rear shockers, so that was going to make things tricky. But before 
that the worst part turned out to be undoing the bolt that holds 
the front driver side shock absorber on at the bottom. The nyloc 
nut on this turned out to fight incredibly hard all the way down 
the thread. Worse, because it goes through the rubber bushing, 
using a socket added enough leverage with all that force that the 
bushing allowed the bolt to twist so that the socket would slip 
off. I had to use a ring spanner instead, which I wasn't strong 
enough to turn in the limited space, so I ended up using my leg to 
push it the whole way. That left a spanner-shaped sore spot on my 
heel for the rest of the day, but I made it. I guess working on a 
Jag with limited tools is one way to stay flexible.

But then I dicovered the reason it fought so hard was that whenever 
the front shockers were replaced last, the mechanic (presumably 
using an impact driver) had either used the wrong size/thread nut, 
or cross-threaded it. So getting it off had made a real mess of 
about half the thread. It also turned out to be the first imperial 
size nyloc that I've encountered on the vehicle, defying my 
attempts to guess the size before removal and buy a selection of 
probable nyloc nuts. So I spent the night trying to clean bits of 
nut out of the threads on the precious custom-machined bolt - where 
I ended up resorting to using a hacksaw blade to cut out between 
the ridges of the thread. Then off to the nearest industrial 
fasteners store (about an hour away) to get the imperial nyloc nuts 
as well as two same-size regular nuts to run up and down the bolt 
repeatedly first and try to re-bore the thread (at least that's one 
trick I've figured out by this stage, although someone watching 
could then accuse you of spending an hour playing with your nuts).

That worked alright, so I think the bolt's still usable without 
risk of a shock absorber coming adrift and introducing a whole 
different sort of shock. Then I went onto the bushings yesterday 
and slowly wrestled one out with the aid of a big hammer and a 
variety of chisels (an essential tool for working on these cars, it 
seems). The most awkward part was cutting the rubber out of the 
middle so that a hacksaw can be fit through the outer ring of the 
bushing and cut a notch through so it can be folder inwards with 
the chisel. It's not a quick job. Inserting the new bushing with a 
G-clamp seemed like a great idea but wasn't, things kept going at 
an angle and frustrating me no end. Eventually I gave up and 
searched through the forums again, to find a unique method of 
socket abuse where a similar size socket is used to press the new 
bushing in by threading a long bolt through it to some washers on 
the other side of the cavity, then tightening a nut up on the 
socket end. That worked well, except that next time I'll need to 
grind down one of the washers so it fits centrally - the bushing 
ended up going in a bit crooked, which was another job for the big 
hammer.

So I just need to do all that again on the other side, and then in 
theory it should all go back again fine, in theory. But this last 
task with the front shockers has turned out to be the hardest job 
so far. I've also now determined that it's an irresistable 
opportunity to replace the rubber boots on the steering rack, so 
I've ordered them, and in theory that should be the easiest job 
yet, but I thought that about the front shock absorbers.

So it goes on. But at least I haven't really wrecked anything 
that's hard to replace yet, albeit narrowly with that custom bolt. 
I like working on the car when things go right, it's just a pain 
that they still often go wrong three times first. Perhaps that's 
why the machanics don't want to know about it anymore, although 
they ought to have the tools and knowledge to avoid most of the 
troubles I have. In a way it's better not to have the work done by 
someone with the sort of uncaring attitude that causes things like 
that badly fitted nut too though. You can't really win either way, 
like with most modern(ish) technology.

 - The Free Thinker