You Have to Roll With It

Having finished the assembly of the front and rear suspension, it's finally time to get the wheels on the chassis and push it out into the sunlight. I realize this post is appearing in winter, however, this work was originally done in May, so yes I’m a little behind with the blog posts, but that explains the sunny pictures

Chassis with front suspension installed.

Installing the Brake disc and calipers 

As shown before I have serviced and repainted all the brake calipers. So before adding the wheels, I will quickly mount the finished calipers. These, of course, will not work yet, for many reasons, but most importantly and obviously, because there is no brake pedal! 

Each caliper is secured to the upright/hub carrier by a pair of M12 bolts. For additional security/old fashioned-ness, to keep these bolts in place, locking wire is paced through each pair of bolt heads and twisted tight. This is recommended by Jaguar for the XJ40 and is the reason for the hole through the bolts for my rear calipers. However, oddly, the bolts for the front caliper carrier were not predrilled. So the first job is to buy some new sharp 2.5mm drill bits, and carefully drill a single hole through each of the four front caliper bolts. Luckily this is a simple job, which if you take your time and keep the drill vertical (ish) it is easy to do. 

Caliper carrier bolt in the vice with a hole drilled through the bolt head. 

With the bolts drilled, its finally time to mount the brake calipers to the chassis. Starting at the front, slide each of the old brake discs over the 5 wheel studs. Once each brake disc was correctly seated on the hub using a little help from a rubber mallet (a few excess paint issues easily overcome) it is secured in place with a grub screw (SNG part number: SF605047J ). I will be replacing these old parts out for new discs (and pads) before I drive the car on the road, but for now, I’m simply using the old ones whilst I gain confidence in my homemade brake lines and brake bleeding (next steps).  

Rebuilt caliper mounted to front upright.

The calipers carried then slide on around the brake disc and fasten to the front uprights with the freshly drilled bolts. 

Calliper bracket mounted to rear hub carrier (forgot to take photos of the fronts).

The caliper (with brake pads fitted) then fits over the brake disc and is secured in place with the slide pins, which pass through the rubber collars and into the carrier. The slide pins are given a small counting of silicon grease to ensure they slide freely. There is also a long metal 'spring' which fits into the two small holes on the front face of the caliper and loops around the bottom brake pads and holds them in place.

Rear caliper fitted, again forgot to take photos of the fronts.

It's then a case of lifting the wheel and fitting it to the hub. The wheels are secured in place with the cleaned donor wheel nuts. Since this fitment is only for moving the chassis around the garage and that I’m sure I will need to take them off in the near future for another job, I am not going to torque these to the correct specs. 

Offside wheel mounted to chassis.

Nearside wheel being expertly fitted.

As for the rear, I have already fitted the brake discs so it is simply a task of repeating the process of fitting the brake calipers, and then the rear wheels! For the rear, as I had already fitted a new brake disc I also fitted new brake pads as well.

Rear wheels on and the first sight of a rolling chassis.

It finally Rolls 

Next comes the simple task of pushing/rolling the chassis out of the garage for its first short little journey. To aid the steering at this point the steering rack was disconnected from the front uprights. Then with one person per front wheel, the chassis can be guided back out of the garage... minding the garage wall. 

First time sitting in my Fred Flintstone style AK Cobra.

After the obligatory selfies sitting in the rolling chassis, it was clear how dirty the garage floor had become over the last 6 months of work. 

The state of the garage floor below the chassis.

After a quick clean and mop, the chassis was pushed back into the clean garage ready for the next stage of the build process, the brake lines or the fuel tank… not sure yet. 

Rolling chassis back in the clean garage!

Going Round and Round

With the front and rear suspension built, the chassis is now waiting for some wheels to get it rolling. A rolling chassis feels like the first tangible step towards a real car, so i'm very excited. There are a few snagging jobs, which I want to do first, mainly clean the donor wheels and grease the new UJs.

Donor Wheels 

When I purchased the donor parts from Simple Performance they sent me five (one original wheel was an odd odd size) donor wheels. Since these arrived they have been stacked up in the corner of the garage under the plastic wrapping which they came in. This was quite some time ago, and hence there is now a pile of boxes and assorted items stacked on topo them. Whilst I will have to find a new home for all the items on top, for progress this has to be tidied up. 

Donor wheels under a pile of boxes

With the wheels laid out on the driveway, it is clear that they are very dirty. A quick blast with the pressure washer got them looking a lot better, at least from the curbside of the wheel. 

The cleaned wheel face 

My larger concern was the state on inside of the wheel rim, which was heavily corroded and dirty. I appreciate that these are only donor wheels and so are only used for the build stage, but given the amount of effort I had gone to clean, paint and rebuild the hubs, I didn’t want to put a dirty wheel on them.  This was mainly because the dirt will soon travel around the garage and car as I touch/move the wheels. A good scrub with hot soapy water got a large amount of the grim off. 

Very dirty donor wheels!

Cleaned wheels, now showing the flaking paint.

Whilst this got a lot of the grime off, there was still lots of flaky paint and encrusted dirt. Nothing a quick light sanding couldn't resolve. With the inside of the rims sanded down they were looking a lot more respectable. 

Sanded inside surface - looking much better.

To then finish the job they had a wipe over with white spirit and a quick coat acid etch primer, to avoid any further corrosion.

Wheels ready for a coat of primer

And hey presto the inside of the wheel rim, (which no one will ever see, and won't even be on the finished car) are now painted and looking much better. As they are only donor wheels I won't give them a top coat of silver, as even for me that's overkill!

After a fresh coat of primer.

Note that there are only three wheels above. My fourth wheel (which I am using) must have been a full-size spare as this was in remarkably good condition and didn't need this treatment.

Greasing Prop Shafts 

An important job which I had omitted earlier was the greasing of the UJs. This should be a quick and slightly messy job.  To start with I got out a grease gun which I brought off GumTree a few months back and gave it a good clean. I wasn’t sure what type of grease was left in the gun or its age to I decided to give it a deep clean to remove as much as I could. 

Grease gun.

With the grease gun cleaned it was time to fill it with some NGLI bearing grease. This was a simple case of putting the opened gun into the grease and pull the lever at the back to suck in a good amount of red grease. 

Bearing grease for gun

With a nipple end attached to the grease gun, if the internet is to believed, this should be a simple as pushing the gun end over the nipple and giving the gun a few good squeezes. When it came to practice, getting access to these nipples was challenging and whilst I was able to get at one, the other 3 proved a lot more difficult. 

One greased UJ, with prop shaft on the car.

Therefore at this point, to make my life easy and because I didn’t yet have a rolling chassis I chose to remove the prop shafts and do this on the bench. In hindsight, it would have been worth doing when I originally built the shaft, but oh well, lesson learned.

Greasing UJ on the workbench.

With the shafts on the bench, it was a very quick job of connecting the grease gun to the nipple and applying a small amount of grease. 

Seepage from greased UJ

With the gun removed there is still a small amount of excess grease around the nipple which can easily be wiped up. Then its time to re-assemble the rear suspension again.... oh joys! 

With these jobs done the next step is to fit some wheels and roll the chassis out of the garage.

Final Rear Suspension Install

Just a quick post to cover the final installation of the rear suspension. I have already trial fitted the bulk of these components before, but have since pulled them apart to finish the assembly of the rear hub and fit the new drum brake shoes. To finish this post and to protect the drum brake shoes, a new pair of rear brake discs are also installed.

Re-fitting Rear Hub Carrier

With the parts layout by the respective rear corner, the assembly process is simple, largely as I feel like I have done this before.

Parts needed to assemble the rear corner.

From my previous trial fitting, I worked out roughly how many chamber shims I needed to place between the diff and the prop shaft. Placing these on the differential flange, the prop shaft was then mounted and secured to it using the old nyloc nuts. I will replace these with new nyloc nuts when I move onto the next stage and torque each nut down.

Chamber shims placed on the differential flange.

Prop shaft attached to the differential.

As before the rear hub carrier is fastened to the swing arm with its fulcrum shaft. Hopefully, this is the last time I will be assembling this, so the shaft gets a good coating of copper grease. The ABS ring is placed into the hub carrier and gently tapped over the hub. Whilst the AK Cobra does not have an antilock braking system (ABS), the ring is key in assembly and I will be making a blanking plate to cover the sensor hole on the carrier later. The assembly is then lifted and rotated into place onto the drive shaft.

ABS ring installed in the hub carrier.

Using the trolley jack as before, the height of the hub carrier needs to be set such that it is 150 mm from the top of the chassis rail. With the hub carrier at the correct height, its chamber can be checked using a range of phone apps, digital spirit levels, and a plumb line. 

Assembled hub carrier at the correct height.

Luckily with my earlier measurements, I was able to get the chamber angle between 0 and -0.5 deg. To get the angles balanced between the two sides I did pull both sides apart once more just to fine-tune the angle. 

Driver's side assembled.

The process was repeated on the opposite side. This is certainly one of those jobs which is very time consuming as there are lots of parts to install before you can check the final measurements which then might lead to pulling everything apart again. 

Passenger's side assembled.

To secure the prop shaft to the hub there is a special single-use locking nut that needs to be torqued to 310 N/m. For the time being, I will continue with the used nuts from the donor vehicle and when I am happy with how the car is sitting I will change these for new locking nuts and try and reach 310 N/mm.

Suspensions Installation

For the time being, I will leave the hand brake cables lose and will deal with them when I focus on the hand brake mechanism. So the next step is to fit the coil overs and the rear suspension. As I had done this before, this went seamlessly. Since this is the last time all the bolts got a coating of copper grease. As with the other nuts/bolts I will not torque them down until the chassis is sitting on the wheels. 

Installation of rear coil-overs.

Drum Brake – Installation

In a previous post, when I assembled the rear hubs I installed new brake shoes. To protect these shoes, whist fitting the rear hubs I covered these in tissue paper. However, for long term protection, its time to fit the new brake discs onto the hub. 

Exposed drum brake fitted to the installed rear corner.

The shiny new brake disc is part no JLM1830 from SNG. I initially ordered the wrong age-related part, and it seemed to fit apart from a small recess in the brake shield which wouldn’t let it seat properly. Before fitting the new correct disc I gave it a deep clean with brake cleaner to remove the protective coatings. 

New rear brake disc.

The brake disc fits onto the hub, by sliding over the wheel stubs, and requires a few gentle taps with a mallet to get the disc fully seated. I noticed that the POR15 painted hub, was too thick around the central disc cutout and so as the disc went on, it rubbed off from of this paint off. 

Brake shoe adjuster – initially full wound in.

To ensure the brake mechanism works when the handbrake is pulled, the brake shoes need to be close to the inside surface of the discs. The resting radial position of the hand brake shoes is controlled by the brake adjuster, which sits between the top shoe segments. This adjuster should be initially fully wound in. With a large flat screwdriver, the adjuster can be rotated which expands brake shoes moving them closer to the inside of the disc. The challenge is then to have them far enough out so they just touch the inside of the brake disc, but not too close that they rub/grind. This is a trial and error process of altering the adjuster, re-fitting the brake disc and checking the hub still rotates freely.

Expanded brake shoe adjuster

Once you are happy with the position of the brake shoes relative to the disc, the final step is to use a grub screw (part SF605047J) to hold the disc in place. These can be purchased from SNG Barret and go on easily. 

Fitted rear brake disc.

With the rear suspension now built up, hopefully, the next step is to put on some wheels.

Let’s Change Direction

The plan for this blog post is to install the power steering rack. Given the instructions are only a couple of pages this should be a quick job. However, as we will soon see it took an odd turn when I had to learn how to MIG weld.

Provided Parts

When I purchased the chassis from AK I included the power steering rack in the parts supplied. As the length might indicate this comes in a long cardboard package, as shown below.

Power steering rack layout on the garage floor. 

In addition to the steering rack, the kit also includes the power steering hoses (not shown) and the two end ball joints, which are shown below. The slight frustration is that the M10x70 mm bolts which are required to install the rack are not included within the kit, so you need to purchases these separately.

Supplied rack ball joints and purchased m10x70 mm bolts. 

The first step is simple, bolt the power steering rack to the chassis with the m10 bolts. This goes on easily.

Steering rack initially fitted to chassis.

However, before tightening the mounting bolts, there is a little warning in the build manual which says “Take care to ensure that the pipes on the steering rack do not interfere with the chassis”. This didn’t read like a common problem or a big issue, however, when I checked my pipes, they were indeed touching the end of the chassis rail. 

Power steering pipes hitting chassis rail.

I initially considered reforming the bottom pipe so it went over the other pipe, but I didn’t want to open up the power steering system as I wasn’t sure what challenges I would then be setting for my self. My next thought was to quickly file the corner of the chassis down to avoid it touching. I didn’t think I would need to file this down that far, and so wouldn't impact the strength of the chassis in this region. 

Filled down corner, so pipes no longer come into contact.

It was, therefore, a step by step process of filling down the corner a small amount and trial fitting the rack. After several gradual stages eventually I got the part to fit without touching. However, I then noticed that I had filled through the weld and opened up the chassis rail. Bugger!! down another rabbit hole I go.

Filled a hole into chassis rail.

The solution was simple, just weld up this gap. The problem with this seemingly simple solution is that I have never used a welder and do not own a welder. Luckily Mark, kindly let me borrow his welder for a few weeks. At this point I should also point out that Mark then came up with an easier solution to overcome the same problem

Kindly borrowed MIG welder.

After a crash course from Mark in how to use a welder and be safe, I was then left to my own devices to get some practicing in. After watching a few YouTube videos, I was keen but nervous to give this a go. My initial attempts were not much to write about. It seemed as if there are three variables; gas pressure, wire speed and arc ‘power’, which all impact the weld. There didn't seem to be a simple method of this variable alters the (poor) weld in this way, to know what things to change. After a few days of practicing and playing with the multiple settings, I was finally content with my welds. 

Practice welds. 

With the practicing over it was time to move onto the chassis. To secure the ground connector I sanded down the near side radiator mounting tab. To fill in the gap, I added a series of spot welds from the left end of the gap building up the thickness as I went. Then after filling down the corner I had a smooth filled surface. 

Comparison of before and after.

With the welding completed, it was time to prime and paint the exposed surfaces. This was not only the fixed region and the grounding point but also I noticed a large patch of flaky powder coating. Since I was going to be spraying etcher and paint, before going any further I had to cover up all the parts of the chassis which I didn’t want painting. 

Chassis covered up ready for priming.

Several light coats of etch primer later. 

Several coats of gloss black later. 

With the power steering rack now re-fitted it is time to put on the tie bar ends. This was thankfully as simple as stated in the build manual. With the ball joints fitted these were dropped into the front uprights. Since I plan to push the chassis out of the garage and will require some steering, I will not fasten these yet. 

Using the suggested 46 turns, I was able to get the required 47.5 inches distance between the ball joint centers.

Ball joints on rack

That's the steering rack fitted, I guess I need to look at the getting some wheels on the chassis.