Preparing for the IRS/Gearbox conversion

6th March 2008
The garage was starting to fill up before I started on the stripping down of the back end. As the gearbox was coming out to be replaced by an IRS 1302s version, I stripped down the brakes to make this removal easier.

The removal of the wheels and drum brakes where fairly straight forward. The wheel bolts where loosened whilst the car was on the ground. As when the car was to be put on axle stands this would be easier to get the wheels off. Once the wheels where off, the drums where visible to be removed. These are secured with a cotter pin and large nut. The nut is torqued up to around 250ft/lbs so you will need a long bar with the handbrake latched on before it will budge. With this nut off it is best to back the pads off. These are retracted by rotating little star adjusters which re hidden in the back of the backing plate by two rubber bungs. You can rotate the star adjusters with the correct tool or a medium sized flat blade screw driver. Turn one at a time to ensure you are not winding them the wrong way and locking the brake up further. With the brake pads backed off the drums can be withdrawn from the shaft. Personally I use a long socket-set extensions held horizontally against the drum and between the backing plate. This can then be hit with a hammer to remove the drum. It is sometimes necessary to move the bar to the other side of the drum so that the drum comes off evenly. The backing plates must have the handbrake cable unhooked. This can be achieved by undoing the nut at the back of the plate that bolts the cable tort. Releasing this gives enough slack for it to be unhooked. The brake cylinder also needs to be disconnected and sealed up.The backing plates are held on by four 14mm bolts with these removed the drive shaft bearing cover plate can be removed and then the backing plate will come off. I placed the drive shaft bearing covers back on so that the bearings would be sealed.

Removing the the shock absorbers was just a case of undoing the respective bolts and removing the shock absorber. It is interesting that the only difference between the IRS and Swing Axle shock absorbers is the wider bush that sits at the bottom of the shock. The bottom bush can be removed by driving in a new one. I had removed the longer bushes from an old set of IRS shocks that I bought with the IRS parts.

You can clearly see in the picture right above that there would need to be some work with the fibre glass body sections to allow the IRS A-Frame arms to travel in their plane without hitting the body work.

I needed to get a friend to help me remove the gearbox as this was a heavy item that would need to be balanced on the jack whilst it was being undone. I would attempt this when a friend was available.