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 tread 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. One 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: https://www.youtube.com/watch?v=q-gdjnCpldI 

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.

Monday, 28 September 2020

Cavity Protection

Now that the underside of the chassis is fully painted with satin black chassis paint I wanted to add further protection to the cavities that lurk within the MG Midgets monocoque chassis. For this job I turned to Bilt Hamber's Dynax S50 (Other cavity protection waxes are available) because it also comes with a very useful lance that evenly sprays the wax all around the cavity walls.




The main areas requiring treatment include the whole rear bulk head that is very easy to access with the chassis on its side. MG very kindly left these holes behind to make this job so easy! 😉 I also applied a coat up inside the spring hanger area.


Other areas that need a coating include the cross member, between the inner and outer sills, front chassis legs, behind the foot plate, insides of the triangular supports, inside the a and b posts, inside the doors, under the front lip of the bonnet. or wherever the car is likely to rust, so basically everywhere! However don't spray this until you have painted that section as the paint will not stick to the wax and you'll have to thoroughly degrease everything!

I watched a couple of YouTube videos on how to do this to make sure I didn't waste too much of the product. 

The idea is to insert the lance right to the back of the cavity, start to release the wax and then fairly quickly pull the lance out of the cavity. The Dynax S50 is quite runny initially to allow it to settle into all the cracks and joints. I choose to apply two coats as I can still remember how badly rusted this whole area was.



Once dried the wax does have a tacky feel to it. So hopefully with the new metal, primer, chassis paint, seam sealer and now cavity protection this will last for a good few years.

Once I have completely finished the car I will probably apply underbody protection.

Saturday, 19 September 2020

Painting Chassis Underside

Having completed the seam sealing on the underside of the chassis it was time to apply some paint. I wanted to use black chassis paint with a satin finish. 

Before spraying on the paint you need to remove any dust, grease and dirt. There didn't seem much to clean as the primer looked so fresh, but the blasting did leave the surface covered in very fine dust which needs to be brushed off first. I then rubbed it down with surface preparation cleaner which helps to remove any left over contaminates which might affect the paint from taking to the primer.

I have applied two coats to make sure the metal is as protected as it can be.

I am really pleased with how it turned out. You can hardly see the seam sealer, but I know it is there underneath doing its job.


I'm going to be getting some cavity spray to add a final protection to the cross member and the rear bulk head which always seems to get hit by rust. Hopefully not anymore!

Sunday, 13 September 2020

Seam Sealer

Having had the chassis blasted and primed it wanted to finish the underside of the MG Midget in preparation for fitting the suspension. 

There are only two jobs really that need to be completed and first up was seam sealing all the joints on the underside of the chassis. 

The seam sealer is a thick glue like paste that seals the joints between two metal panels. It can also be used on welds that have some pin holes left behind. Once applied it drys hard and can be painted over.

I wanted to make sure that every seam and joint was carefully covered whilst not spoiling the freshly blasted metal, which looked so nice and clean with its coat of primer, but it is so important to stop any moisture from entering the gaps as I don't want to be doing any more welding for a good many years to come.

I soon realised there are quite a lot of joints on a monocoque chassis! Here are some photo's of the work, although it isn't that easy to see the seam sealing as it is also grey like the primer.


Now that has all been completed on the underside it is time to prepare for painting the underside with black chassis paint which will protect it from moisture, stone chips and general usage better than standard paint.