Saturday, November 23, 2019

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.