Thursday 8 October 2020

Front Steering and Suspension

At long last I can now focus some time towards restoring the parts for the MG Midget. My plan, now that the underside of the chassis is ready is to convert this lump of metal into a rolling chassis. To do that I need to strip down all the suspension and steering at the front and back and restore what I can and replace those parts that are too worn with new.

First up is the front steering and suspension. I took this off the car back in January 2013 totally covered in dirt and rust and both have been sitting in my garage ever since.

First off is to dismantle all of the components and then make assessments of each part. Initially wasn't going to post this on the blog, but then felt it might be useful to someone else as well.

Right then here we go!

Detach the wishbone pan from the kingpin and stub axle.

To do this you need to unscrew the fulcrum pin which is hidden behind this grease nipple and plug.

The grease nip should unscrew normally. It is worth testing to see if the ball bearing in the end still moves with a pointed tool.

Then unscrew the plug, mine is fairly corroded and will need replacing.

This exposes the fulcrum pin. A large flat head screwdriver should be enough to unscrew this, but it won't move until you have removed the cotter pin from the bottom of the king pin.

This nut should come off fairly easily.

What will be more difficult to remove is the cotter pin itself, because it will most likely be wedged in place and the only way to remove this is to hit the thread end of the pin which is likely to damage it. Fortunately these are replaceable and not more than a £2 including a new nut.

Now the fulcrum pin can unscrew. Luckily mine came out without much fuss.

It is now possible to separate the wishbone from the king pin and stub axle. The red circles are where I showed someone the screw points for the brake disc dust cover. The third bolt is hidden behind the brake disc.

Once separated you'll find these two cork seals on either side of the king pin which need to be replace.

Next I moved on to the wishbone and I needed to remove the rubber bushes

This was very easy and the rubber bushes need to be replaced but the bolt, washer and nut are all good.

Then on to removing the spring seat. These bolts were very rusty and stiff and required some penetrating fluid and long handled socket set.

Eventually it came off.

And that is the wishbone dismantled and ready for restoration. 

Now on to the stub axle, king pin, hub and disc.

First is it to slacken off the hub nuts

Now for whatever reason I didn't have either of the front dust covers that slot into the end of the hub. This obviously needs to be removed to access the hub nut. I'll be adding two of these to my shopping list.

Normally there would be a split pin holding the hub nut in place but as you can see that is also missing. I'll be adding two of these as well to my shopping list.

With the hub nut removed you can get access to the hub washer and you then need to remove that.

Then remove the four hub nuts so the hub is loose. Now the chances are that it won't slide off because the bearings are holding it in place. So you need to pull the hub off the stub axle.

There are specialist tools for this job, but I do have a valve spring compression tool and found this worked really well.

Now because my Midget has wire wheels my hub is longer than the steel hub this means that the outer bearing will probably be still in the hub, but the inner bearing will either still be in the hub or on the stub axle as shown here, which will need to be pulled off. Again there are specialist tools to do this but after removing the brake disc dust guard my spring compressor did the job. There is also the bearing seal which is fairly simple to remove.

I did have some real issues with my bearings on both axles. On one side a prior owner had fitted the outer bearings the wrong way round which meant they were extremely difficult to remove. You can just see in the photo below the outer case of the bearing (called the race) still stuck in the bottom of the hub. The inner part of the outer bearings came out because they were fitting incorrectly and probably over tightened which forced the bearing further into the hub. 

You can see here the damaged race of the bearing bent and pushing into the hub spacer. 

You can see here how the bearings have worn into the hub's outer spacer after I managed to remove the race. So I have no choice but to replace the hub. 

Now normally to remove the bearings you use a tool called a drift which is a metal bar that you can place in these cut out as shown in the photo below. Taping the drift gently either side will remove the bearing. On the wire wheel hub there are only cut outs next to the inner bearing which makes it more difficult to remove the outer bearing. 

I had to use a flat headed screwdriver to remove the incorrectly fitted outer bearing race. On the other hub as both bearings were fitted correctly both came out using a drift and hammer.

You will also find the hub spacer within the hub between the two bearings. Fortunately both of mine were not damaged at all.

Next up is to remove the king pin from the stub axel. To do this you have to first remove the top trunnion. This can be simply done by removing the top locking nut. On the trunnion there is a rubber bush that needs to be remove and in my case replaced with new.

The only thing left to remove is the dust cover at the back of the stub axle.

During the removal I noticed that there was an issue with the king pin bushes that sit in the stub axle. The problem with them is that a prior owner had fitted them incorrectly (similar theme with this car). On all four bushes there is a hole that needs to line up with grease holes in the stub axle. You can see below the bush as it was removed. The two holes should align when fitting.

To remove the bushes will require the correctly sized socket that matched the circumference of the bush. You can then press or hit to drive the bush out. I advise you use plenty of heat and penetrating fluid to help get these moving, but once it starts to move it does come out. It is likely that in removing the bush it will damage it and so will need replacing. If you do replace the bushes the king pin is unlikely to fit in the new bushes and will need to be reamed, which is the process of machining the bushes to fit the king pin perfectly. You can purchase or rent the tool to do this yourself. Here is a video that shows the process: 

I have a specialist engineering company local to me that is going to do this for me.

Apart from the bearings this task was fairly simply. Some heat with a blow torch and penetrating fluid was definitely used on some nuts and getting the the bearings out. With everything disassembled it is now time to start to clean up and restore these parts.