Differential - Pt 1

I have got a 3.54:1 Powerlock differential. It has a very smooth operation and very little backlash. I only intend to replace all seals, side shaft bearings and give it a really good clean up generally.

Before re-furbishing

Removing the rear cover proved rather more difficult than I had hoped. It was really difficult removing the two pendulum studs through the diff cover. Looks like they have been off at some point in the past so the heads are a little damaged. Still, I was able to find a couple of replacements from Jaguar Heritage at a very reasonable cost.



I needed a rather long extension to my spanner!!!



Removing the side shaft. I had to resort to my trusty slide hammer
as someone had decided to superglue the bearings in!

It took some time in getting the bearing collars off as these are an extremely heavy press fit. The only option is to cut them off. A combination of an end mill in my pillar drill and the depth stop very carefully set. Then a good go with the angle grinder and off they came. No marks on the shaft so I was really pleased. Good job the bearings are being replaced as well as the seal. The splines are a little worn but should be OK. Only time will tell.

Finally all out and the bearing collars removed

With the side shafts and the diff cover removed the nest task (after sealing the inside off from dirt ingress) was to very thoroughly clean the diff housing. There was patchy paint and a lot of rust. I decided to use POR-Strip for paint removal and this worked a treat. One thing to bear in mind is to use proper safety gear and use it in a very ventilated area (outside is best). Read the instructions very carefully as this stuff doesn't take prisoners! After this it was carefully cleaned and all traces of the stripper were removed and then I set at it with wire brushes. In the end with all rust and paint removed it looked pretty good.

Stripped and wire brushed. A bit of a labour of love but definitely worth it.

All masked up and painted. I chose to use Eastwood paints, Extreme Chassis Black,
primed and then followed by 2 coats of satin black.

More to follow later when I get the diff cover back and start reassembly of all the parts. I still need also to change the pinion oil seal as well.

Donor Parts - Pt 3

I have now had the hub carriers Silver Xylan (PTFE based coating) coated to bring them back to nearly 'as new' condition and to give them a little more protection. Also most of the steel suspension parts are now Black Xylan coated. They will be much easier to clean. The other satin black parts are all sprayed with Eastwood Extreme Chassis Black primer and then Eastwood Extreme Chassis Black Satin top coat. Two coats of each. I must say that these have come up looking pretty good as well.

Rear hub carriers before refurbishing

Here are the parts refurbished so far. More underway.

Handbrake

I must be a bit sad really. I'm never happy with just a quick clean and polish, the parts have to be as good as they can possibly be (at least that is what I think!).

I managed to get a complete handbrake mechanism from good old eBay. The only part missing was the mounting bracket but this is replaced by an AK part so no worries.

When I got it was not too bad although it was pretty grubby and fairly rusty in a number of places.

As received. Not bad but could be much better.

I took quite a number of photos before I dismantled the assembly just to make sure I knew how it all went back together correctly.

On the right hand photo the distance the small starlock washer is pressed onto the rod is really important.

I completely dismantled the lever assembly to check all parts over. I decided to get all the zinc and yellow passivated parts re-plated and the lever re-chromed. The re-plating process essentially means that all parts are dipped in a solution that dissolves the old plating but leaves the steel untouched. This leaves the original metal rust free and ready to re-plate. 

Before dipping,

After dipping and re-plating the parts are essentially as good
as new. No more corroded parts.

I have managed to obtain the necessary split pin and press on lock washer. The thumb plunger and spring were perfectly OK so I have left these as was. The main lever itself has been re-chromed. Then it is a simple matter of re-assembling and then storing safely for later.

All re-assembled and positioned on the AK bracket ready to be fitted.

Rear Brake Shoes

I have had no luck in sourcing the Girling version of JLM800 handbrake shoes so I am going the re-lining route. I have spent quite a while searching the internet and then made several phone calls and arrived at Villiers Services. They are essentially a motorcycle specialist run by enthusiasts, based in the Midlands, who also do re-lining of brake shoes etc. Basically you send them your old set with info on make of vehicle, driving requirements etc., in this case, purely handbrake. They then fully refurbish all the shoes fitting the correct lining to the original specification. All the old lining materiel has been removed, the steel work is blasted and all is given a nice coat of paint.

Before........

After a short while I received the rear brake shoes back through the post and I am really pleased with them. They really are as good as new! I will use this process again as and when I have the need. Total cost for the re-lining was £35.90 including delivery.

Re-lined and refurbished parts. They look as new!
Really pleased with how they have turned out.

Heater Assembly - VW Polo Mk2

I have read several build logs recently that include the refurbish of the heater assembly. I think that I was quite fortunate in getting a pretty decent one from a breakers via eBay. Only paid £40 inclusive delivery. On closer inspection it looks like the heater assembly may have been separated in the past. Despite this I decided to replace the heater matrix with a nice shiny new one and also the small hot/cold regulator O-ring.

To split the 2 halves of the plastic surround you have to carefully depress the clips circled (more than just 2!) whilst trying to pull the halves apart simply working around the joint. Once I had found a suitable size screwdriver it proved to be not too difficult. Just needed to keep pressure applied else the clips wanted to snap back together.

The next job was to thoroughly clean all the parts and then re-assemble. It took quite a while and was actually worse on the inside than out.


Donor Parts - Pt 2

Well, what can I say. Its been some time since my last post and I have accomplished a fair amount since then. I have managed to dis-assemble all of the suspension parts now into a more manageable pile! (No photo I'm afraid!)

One thing I must stress is that you very carefully read the parts AK need for modification!!! After dismantling into more manageable parts I had a rather excessive clean up of my garage to make a little more space.

In my haste I disposed of the lower rear wishbones having convinced myself that these weren't needed as the chassis comes with tubular ones! The only thing I forgot was that the rear hub carrier bolts to this using the original XJ40 bracket!!! I must say that Jon at AK didn't laugh too much (well at least when I was just checking what parts he needed from me). Oh well! Another lesson learned and another good priced purchase from eBay.

2nd set of  Rear Wishbone's

All the calipers were re-furbished through Anthony at Black Country Jag and a great job was done. They look really good now, much better than the rusty lumps that I started with! I purchased ATE front caliper setup but retained the original rear Girling calipers although rear brake shoes are proving rather elusive. Anthony supplied most of the necessary suspension and brake parts for me at a very reasonable price. He's a really knowledgeable and most helpful chap. The few parts he could not supply came from SNG, again really good to deal with.

Caliper's all looking like new

Regarding the rear handbrake shoes I noticed recently whilst reading through Andy Menzies AK build, that he has had similar issues of getting hold of the Girling JLM800 rear handbrake shoes. ATE seem to be the ones supplied. He was fortunate to find a local supplier who had some in but they are now out of stock and not expecting any more! One thing he did mention was that I could consider having my old ones re-lined. Looks like this may be the way to go as the old ones aren't too bad. As they say, "watch this space".

Engine - Pt 1

I spent quite a lot of time thinking about the engine specification I want to fit into my Cobra. It had to be a Ford and my budget would not stretch to a 427! so either 351 or 302. Eventually I came across another builder who had very kindly posted his engine build in great detail. (see Martins GD Cobra build in the links list)



Mark & Punch the Centres

I managed to purchase a 302 roller block dated 1986 from Peter Knight Racing, they will be performing the set-up and dyno testing a while down the road. It looks to be a very nice block to start with. This will eventually be stroked to 331ci rather than pushing it all the way to 347ci. I am after plenty of 'grunt' but ultimately want as strong an engine as I can achieve. I will have to wait and see what power output I get when all is finished.

This is now at the machinists (Dave's American Machine Shop) being chemically cleaned having all of the core plugs removed, bored and decked, new cam bearings fitted and the smaller core plugs all tapped rather than press in. I am sure that there will be a few other jobs done on it whilst it is there!

Should get this back in a few weeks. Can't wait.

Sadly I received the news from Dave that after the first deck cut the block was very badly cracked for about 25% of its face between coolant cores and piston bores. The block was scrap! This was a huge disappointment and was completely unexpected as apparently this is a most unusual place for these to crack.

At this point I had to make a call to Peter Knight Racing who immediately replaces the block with another one. Absolutely no quibbles I must say I was both extremely relieved and very impressed. As you can see from the photos this block is 1 year newer at 1987.


302 Block 2

The new block is now back with the machinists and here's hoping that all goes well. I should know in about another week.