MGB Replacing Rear Suspension Bushes
The following is the procedure used by myself when I replaced the rear suspension bushes on my MGB.
First task was to place chocks on both front wheels, front and back, to prevent movement of the car.
Then I jacked the back of the car with a trolley lack under the centre of the differential sufficiently high enough to place jack stands under the car in front of the rear leaf spring eye connection to the body. I then lowered the differential to just before the retention straps tightened and placed jack stands under the differential.
Then as I already had the hand brake applied and the car in gear I was able to undo the wheel nuts and remove one of the back wheels from the car.
I then placed the trolley jack under the spring plate, at the differential on the side from which I had removed the wheel, and just took up the weight of the suspension with the trolley jack.
I then unbolted the rear damper connecting arm from the spring plate. I also unbolted the connecting arm from the rear damper and removed the connecting arm. Picture to the right showing the connecting rod attached to the damper.
Then undid the 4 nuts of the U-bolts securing the spring plate to the differential tube. After removing the nuts released the trolley jack slowly to separate the spring plate and the leaf spring (Which was under tension) from the differential tube until the leaf spring was relaxed and the trolley jack free from the spring plate.
After removing the spring plate, U-bolts, spring seat damper rubbers and supports and the bump stop from the differential tube the rear spring hangers were unbolted and removed.
Spring seat damper rubber and supports shown in picture to the left. The rear spring hangers as illustrated to the right (These are actually shown after reassembly with new polyurethane plastic bushes and painted hangers as well as leaf spring).
The front leaf spring eye bolt was then removed. Often if the suspension has not been disturbed for many years the front eye bolt is seized and difficult to remove . In those cases the bolt head is cut off and then the bolt driven out with a steel drift.
However in this case it was free and was able to be undone.
To enable removal of the old eye bush, and installation of the new polyurethane bush, a simple tool was made from a length of threaded rod, long nuts , a length of 2 inch pipe and a suitable size socket as above. The photograph below illustrates use of the tool in removing the eye bush.
Whilst the springs were out the dampers were also removed, cleaned externally, drained and cleaned internally then refilled with shocker oil and repainted before re-installation into the car.
The suspension was installed in reverse order to the dismantling after wire brushing and painting of components with black epoxy enamel.
The photo above how to use made up tool to insert new polyurethane bush. The narrow end of the bush should be offered to the spring eye first and the installation tool will distort the bush until the end is inside and when it is at the end of the eye replace the washer with the 2 inch pipe to allow the end of the bush to come out of the spring eye. Use the tool to insert the steel centre bush which prevents crushing the outer polyurethane bush when tightened.
The aforementioned process was repeated for the other side spring suspension. It is not recommended to dismantle both sides at the same time.
When I wire brushed my leaf springs, prior to painting, I was surprised to find plastic interleaved between the spring steel leaves. My follow up research revealed that MG did include the plastic interleaves on later spring sets to soften the springs by reducing friction between the spring leaves.
Another improvement introduced with Rubber Bumpers?
All components of the suspension system were wire brushed to remove rust and grime before being painted with black epoxy enamel.
On The Marquw May 2020.