1991 Jaguar XJ-S

Update your progress on your various car projects.

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AKROVER
Posts: 303
Joined: Thu Sep 01, 2005 2:49 am
Location: Hot Springs SD

Re: 1991 Jaguar XJ-S

Post by AKROVER »

Yesterday and the day before were my two most intense workdays on this car so far. I worked 6 hours yesterday and 8 on Monday. I wasn’t expecting so many challenges in assembling things.

My first struggle was with the lower control arms. The bearings on the pivots want to fall apart. There is an inner sleeve that is wider than the pivot point. On either side of each pivot point, there are three concentric rings that rest on the edges of those sleeves. The inner ring is basically a washer. The outer ring is just a metal ring. The in-between ring is a rubber grease seal. These four sets (two pivot points per arm and two sets of rings per pivot point) balanced precariously as I tried to slowly insert the heavy assembly into the housing. There are also large washers that go outside of those seals while the 16” axle gets inserted through both pivot points. It is a job for someone with six hands. I managed to hold one side reasonably together, squeezed in the big washers and inserted the axle. The other side had to be reassembled in a tight space. Luckily there is some flex in the housing that allowed me to pry open some room while I gently inserted the concentric ring assembly, a tedious process requiring about a dozen tries before achieving success. When I moved to the second control arm, I saran wrapped the assemblies together. I am not sure I got all the saran wrap out, but I don’t think that will present a problem.

After that, I was able to motor along, bolting the axles down which sandwich the rotors. The next step was installing the new springs/struts. I realized that I was going to have to turn the assembly sideways on my dolly as the arms drop down too low for the way I had things oriented. This means I will have to slide the stationary wheels of the dolly sideways to move the assembly under the car, but the weight is mostly on the smaller pivoting wheels so I can probably just pick up the back of the dolly with the jack and roll the entire thing sideways. I suspected this was going to be necessary, but I wasn’t sure until I started to put on the springs.

Luckily, I realized that prior to pushing the pivot axle for the springs forward, I had to install the new radius arms. Those cannot be tightened until they are fully connected to the car and the car is sitting level, but the bolt has to go in before the front spring, another of those crazy thoughtless bolting details. There were a few washers in the mix of all these pivots that I wasn’t entirely sure about, but the number and sizes worked out logically. If you look in the picture below, you can see the radius arm (bungeed up to keep from scraping on the concrete) pivots are tucked behind those front springs.

Yesterday was supposed to be an easy day. I just needed to fabricate a few brake lines and install the calipers and handbrakes. Installing the calipers turned out to be a nightmare, even worse than taking them off. I think one problem is that the holes did not precisely align with the mounting bracket holes (I’ll blame the Chinese calipers for that). I was able to force the first one together, but that meant that the bolts were tight the entire way, a quarter turn at a time. Over half the turns had to be done with an open-end wrench because there was no clearance for a box wrench. I am glad I didn’t buy that set of Gear Wrenches I looked at the other day as those were too thick to fit in there until the end. I had two box wrenches of the right size in my collection and only the thinner one was really useful. I opened up the hole a little on the second caliper, but then ran into another problem. I managed to get the lower bolt to engage, but then the caliper wouldn’t rotate far enough to line up the second hole. I ended up grinding off a part of the caliper housing that was bottoming out and then finally jammed the bolt into the hole and repeated the quarter-turn-at-a-time joy of the first one. If you look at the picture, the mounting bolts are on the inside of the calipers behind the cylinder. The work is jammed between the caliper and the differential. There is so little room to work in there that the bolt cannot be removed until the caliper is pulled out.

I really didn’t understand how the handbrakes work until I began to assemble them. The first thing I ran into, though, was the realization that the stupid routing originally used for the driver’s side brake line was because of the handbrake lever. I now have to fabricate a new brake line for that side. I looked at the two points and chose the easiest routing, a foolish mistake. It seems every line I have fabricated has required repeating the process. The first set of crossover lines couldn’t be re-used with the new longer fittings because the first bend was too close to leave room for the flare tool (flare before bending).

The handbrakes are weird, for sure, but they aren’t as bad as I thought. They were merely a minor hassle to assemble and I think there is a chance that they might work OK. I didn’t want to adjust them too tightly, but they do seem to open on both sides when the tension on the arm is released. The old springs aren’t actually terrible, but they do need to be tightened up so I will probably try to bend those to tighten them. If they break, I can buy some new springs and fabricate them to the correct length.

With as much cleanup as I have done, I thought the assembly work would be relatively clean, but I seem to always grab a dirty spot that I missed. The anti-seize didn’t help me stay clean either, especially when I dropped a small bolt into the jar and had to fish it out. My hands are raw from constant washing and my Gojo is running low.


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AKROVER
Posts: 303
Joined: Thu Sep 01, 2005 2:49 am
Location: Hot Springs SD

Re: 1991 Jaguar XJ-S

Post by AKROVER »

The car is sitting on its own wheels right now, although the wheels will be coming off for the final steps. Everything went really well this afternoon. I fabricated the last brake line and then stood there wondering what else needed to be done. I greased a couple of fittings, but then decided it was time to roll this thing back under the car. That worked exactly as planned. I was able to angle the dolly under the car and then rotate it to start the IRS into the gap. Once the dolly was north/south on the car and the IRS was about halfway in, I slid the jack under the dolly and picked up the big stationary wheels. Then I was able to roll the complete mess perpendicular to the car using the jack and the two swivel wheels on my dolly.

I hope I lucked out on the speed sensor. The one tab broke off at an angle so the broken piece actually engages with the main body of the sensor and provides some downward push. The other bolt tab was fine and probably would have been adequate by itself. The way it is sitting there with both bolts and both tabs in place, you couldn’t tell it was broken without removing a bolt. I think I dodged a bullet there as I could not find a replacement for that online. I think that is the speedometer feed so I will find out soon enough.

I next attached the ABS sensors to each wheel and installed the new cable guide screws that I found in my hoard. They worked perfectly. I then tried to tackle the handbrake cable. I got one side in, but the cable isn’t long enough with the new pads. I tried loosening the adjusting screws inside the car, but the cable doesn’t seem to be sliding out further. I decided that wouldn’t be any more difficult to address with the IRS mounted so I left it with the one end connected but the other end loose.

The next step was the big part of the plan, jacking up each side to align the mounting bolt holes and sliding the mounting bolts in. Before starting, though, I slid the jack under the dolly and was able to lift the IRS assembly up by putting the jack head between the rails of the dolly. That allowed me to slip another 2X8 under the IRS so that it sat a little higher on the dolly. Then I only needed to jack each side a little to get the mounting bolts inserted. It was some elegant one-person material handling with a very heavy assembly.

Once the IRS was bolted up, I put the jack back under it as that is the proper way to jack the entire rear of the car to put it up or take it off the stands. It also adds some safety when working underneath. The car was still resting on the stands, but the jack was there as a backup as I crawled underneath. I first inserted the exhaust pipes. Those went in easier than they came out, but I think I had the car sitting quite a bit higher this time. The pipes are resting on their support inside the IRS. One of the rear mufflers is already loosely attached and resting in its support. I need to buy a couple of new clamps and some new flange bolts to finish the exhaust. The next challenge was the driveshaft. It was awkward, but it all went together nicely with brand new hardware.

I thought about quitting at that point, but there was still some time left before dinner, and I was already a filthy mess so I decided to get the radius arms connected. I had reset the jackstands after removing the old radius arms so those had to be moved, first. I decided that the easy way of putting some load on the springs to level out the arms was to simply put the wheels back on and lower the car, getting the jackstands completely out of the picture. The radius arms required a little help from the jack to slide into place. I had to re-use some old crusty bolts, but after cleaning them up and adding a little anti-seize, they went in easy and clamped down solidly on the radius arms.

Replacing rear springs on a 34-year-old car is expected to alter ride height. They should settle a little after a few miles, but right now the look is quite different. The car looks like it is heading downhill, and the rear bumper looks like it is way up in the air. The springs are soft as the car bounces easily and settles immediately with the new struts. The surprising thing about the way it looks is that when I measure the actual gap between the top of the tire and the wheel arch, the front and rear are less than a half inch in difference. I think the problem with older cars is that nobody really knows or remembers what they looked like new. Most of these today are probably running around on saggy old springs so we end up thinking that is the ‘right’ attitude. The picture below does a decent job of showing the similar wheel arch gap front and rear and if you look at some of my older pictures you can see how squished down the back was. I suppose the bigger question for me will be any differences in handling and ride quality, but it takes some getting used to when your car’s attitude changes.

The final steps should be getting the exhaust buttoned up, tightening the rear radius arm bushings, and bleeding the brakes. I will take a closer look at that handbrake cable, as well, but that is not a high priority. If all goes well, I might even park it downtown on the fourth as part of the local car show.


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GMJohnny
Posts: 1296
Joined: Wed Feb 04, 2009 10:56 am
Location: Auburn Twp, Oh

Re: 1991 Jaguar XJ-S

Post by GMJohnny »

After reading this, I’m amazed at the engineering that went into the IRS on
your Jag. It seems a bit over complicated to me, but the majority of the cars
that I’ve worked on are very basic- almost tractor-like so anything different
seems complex. The struts don’t look too horrible to remove from the car with
the IRS assembly in place, so if you hate the new ride height, I’m sure you
could do something to adjust the springs. I’m a stickler for the “correct” height
(whatever my mind gets stuck on) and I can remember going out and measuring
my spring work almost daily after a spring install to see if gravity had helped
my situation out… most of the time, I’d lose about 1/2” height after it was all
said and done. Hopefully, it will settle to a height you’re happy with!

GM
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