Rear Axle - Jag Rear Overhaul - Part 10

I took a step backwards this afternoon to take two steps forwards.....

If you go back to the Jag Rear Overhaul Part 3 .......(I still can't quite believe that was way back in 2012).....you will see that the axles and the universal joints were all assembled and ready to be installed. UNFORTUNATELY though I experienced a Muppet moment shortly after this and had to have them all pulled apart again. So why did I go backwards like this?

Well you see I sent the freshly chromed axles and the hubs away to a Jag specialist to be assembled as the bearings in the hubs need to be pressed in to a specific "pre-load". That means they get put in with a tiny bit of play to allow the bearings to run freely without binding up but not so loose that the wheel wobbles about. It is quite a specific measurement that requires special tools. So a Jag specialist seemed like a good idea.

As I mentioned though I ran into a Muppet who was working there and was assigned my job. In his wisdom he put the freshly chromed axles in the vice so he could tighten the big nut on the end of the axle when it was being mounted in the hub! Yep thats right chrome in a vice! Guess what it cracked the chrome....next step would be for rust to form and the chrome to start falling off. What an idiot! Not only once but twice! He did it to both axles!

Thankfully the company came to the party and paid for the axles to be re-chromed, but it meant disassembling them again so that could be done. Grrrr.

Now while they were apart I thought more about the universals. Heres one below. You can see this one has been marked so that each cap goes back onto the right shaft when they are reassembled into the axles.

I decided that while they look okay, that seeing as I had them all apart again, I would paint the universals. They are covered in a plastic clear finish, but over time they could rust especially given they are in quite a hostile environment under the car and near brakes and brake dust in the case of the inner ones. It is a lot easier to paint these now while they are out than it would be when installed. What better way to spend a Sunday afternoon!

So the first thing was to clean all the parts and mask them up. In the case of the centre cross they had a few casting marks that I smoothed off with a Dremel (a small hand held grinder). Here is one all masked up and ready for paint. There are 4 of these and it literally took hours to get to this stage.

Once all were masked I made a board with holes in it to hold the crosses and laid the cups out in a row so I could spray paint them from all angles.

Here is the finished product all painted with the matched cups back on the correct shafts on the centre cross. It doesn't look a whole lot different to what I started with but they are protected from the elements now and won't go all rusty.

Now while I had the paint out I thought I'd also attack the hubs. You can see here what a nice job Jack the metal polisher did for me. These hubs are about 50 years old now and they were peppered with stone chips and grime from all that time being dragged around under a car.

Jack is an absolute wizz. A real nice guy and he charges very reasonable prices. His operation is very old school. He has a tin shed in an industrial area that you'd struggle to find if you didn't know where it was, but his reputation is so good that people come from near and far to get a good job done. Here he is hard at work on someones alternator.

Here's the shed. Very unassuming, but the stuff that comes out of here is nothing short of superb!

Anyway back to those hubs. When Jack polished them I told him not to worry too much about the inside of them as it would have been very difficult to get at to polish but also really difficult for me to get at once assembled in the car to keep the aluminium shiny. Instead I decided to paint this part of them. You can see here how they are still natural aluminium and a bit black from the polishing dust.

So I cleaned these, masked them up, primed them, painted them and gave them a shot of clear coat. Not as good as polished alloy, but they look okay and will be fairly easy to look after once installed. 

Thats another weekend shot and quite close to being able to finish reassembling the back end. Keep watching!

Rear Axle - Jag Rear Overhaul - Part 9

The next step is to start assembling the driveline that goes between the diff head to the wheels. This consists of the axles which I covered in an earlier post (click here to view) and the bottom arms. The bottom arms are something I have never really liked about the Jag rear.....they are okay and once chromed look quite good, but they are a big fat tube that to me is kind of ugly and they are something that lets everyone know that you have a Jag rear in your hot rod. Here's what the jag rear looks like. Either side of the diff head you can see the axles on top and the fat tube bottom arms running from the diff head out to the bottom of the hubs.

I have always been a bit keener on something like these "Heidts" brand rear ends with a 'ladder' type bottom arm. See the difference, just looks a bit more clean and "hot rod like" in my opinion.

While my chassis was being built in Wellington at Juniors Kustom Rides, I asked them to give me a price for building arms something like the Heidts ones but to be fitted to my Jag rear instead of the fat tube bottom arms i.e.swap out the fat tubes and insert the ladder type set up. 

Juniors actually went one step further than that and went ahead and made some out of stainless. They looked spectacular and I would have loved to buy them, but I couldn't afford them though at the time and last I heard they were selling them to another guy that had an F100 truck with a Jag rear in it. I was kind of gutted as they looked very good and were really well made, but alas I just didn't have that kind of cash. Not to worry....so I went ahead and had my original Jag ones chromed. 

Now some months later Juniors Kustom Rides unfortunately ran into issues and closed down. All their workshop equipment was being sold off on Trademe at $1 reserve. I was interested in what sort of hot rod related tools they might have so I took a look....shrinkers, stretchers, grinders, welders, lathes and bottom arms for a Jag rear......whoah hang on a minute what was that????? Yep thats right stainless steel custom made arms for a Jag rear...$1 reserve auction! I was beside myself and kept a very close eye on the auction. It eventually closed with me winning the arms for $330. YES!!!! 

This is what they look like compared to the Jag one at the bottom. 

 And here you can see how they made the new custom arms with the exact same geometry as the original Jag one. Laid one over the top of the other you can see all the mount points are identical. Nice! Ignore the smeary marks on everything. I am keeping everything smothered in a film of oil as we live close to the sea and I want to keep everything protected through the build process.

Now having the geometry on the new arms identical to the originals means everything bolts up just the same as original. The inner ends pivot on the brackets that are bolted to the side of the diff head (they are the ones I put the safety wires on in my last post). The arms pivot up and down with suspension travel and as such have bearings so they don't wear out. Here you can see I have the two new bearings fresh out of their boxes and the sleeve that runs inside them. 

All of this needs to be put inside the hole in the bottom arm that is at the top of the photo. Here is a close up of the bearing. It is what is known as a needle roller bearing. The little needle like pieces inside the bearing are hardened steel and so long as they are clean and well lubricated with grease they will last for a very long time. Excuse the grubby fingers....thats what you get when installing bearings with a lashing of new grease. Lovin' it! 

 The bearings have what is referred to as an interference fit....in other words the hole they go into is slightly smaller than the bearing. We are talking 0.1mm here so only a tiny fraction but it means they are very tight in the housing. If you had a hydraulic press you'd use that now, but I don't so we have to improvise. By lining the bearings up and threading a bolt through the centre with big diameter washers pressing against the sides of the bearings....its just a case of carefully tightening up the bolt and letting the big washers slowly press the bearings into place. Here you can see it all set up ready to go. 

 And here is one all finished and pressed into place.

Thats another job ticked off in the reassembly process. Keep watching for more!

Rear Axle - Jag Rear Overhaul - Part 8

The next job (after the paint and clear lacquer on the diff head hardened) was to colour sand, cut and polish. It does seem strange to have a nice shiny paint job then attack it with sandpaper, but that is exactly what you do.

When you put the clear on it has little fine bumps, stipple or orange peel that makes the finish a little less shiny. To get that real mirror finish shine you have to sand the surface with very fine sandpaper to remove that stipple. You have to be careful though to only take that surface off and to not go through the clear coat to the coloured paint as that would mean starting all over again.

Once the sanding is done its then a case of using a cutting polish to take out the fine little sandpaper scratches. After that its on with a finishing polish. David you might remember giving me a tin of Carnuba wax some years ago....well thats what I used here and it came up really nicely. Sorry the pictures aren't great as they are all taken at night, but here's what it looks like after cutting and polishing. I mounted the brake caliper mounting plates and the diff quick change cover just to see what it was going to look like with a bit of bling.

Its hard to see in this light, but here is a close up so you get an idea of the gloss that is on the paint finish. I have to say I am pretty happy with my first ever attempt at painting. 

Now in my last blog you might recall I ran into a bit of an issue with retaining the bolts that hold the brake caliper mount in place and also hold the side covers on the diff head. If one of these came loose it could actually lock the axle up. If that happened at speed it would be disastrous!!!!

You might also recall I was looking at using a safety wire threaded through the bolts to stop them coming loose. This is a safe solution but not so sexy to look at. I came up with another idea though that looks a whole lot nicer and will be just as secure if not better.

I had some lock rings made. In effect they are a bolt on cover that bolts over the top of the caliper mount bolts. Here is one of the covers I had cut from ali and have had polished. Now you can't argue with the fact that this looks much better than a safety wire!

In the next pic you can see the caliper mounting bracket with the 5 main holes that hold it in place. In between those holes there are smaller holes that the lock ring will screw into (thanks Roger for all you help with these)

And here you can see what it will look like with the lock plate mounted. Note I made the lock ring slightly smaller so I can still see the very edge of the main bolts. That way I will be able to see if anything starts to move or loosen.

So to mount it all up I put the main bolts in and used loctite (a type of glue that stops bolts coming undone without significant force) and then I bolted the locking ring on over the top also using loctite.

The theory is that if something did come loose it would either be a small screw and it would just shear off and not lock the axle. You'd hear it and feel it though so you inspect and rectify at that point.

If I was unfortunate enough to have one of the main bolts come undone, it would need to distort the locking ring and if that started making contact it would make a hell of a noise and would slowly grind. It would not cause a catastrophic lock up though.

Here it is all mounted up. Looking good.

Now while we are on the topic of the safety wire there are a few bolts that do need to be wired. Its in the certification rules that they need to be and it makes sense as they are quite integral to the structure of the rear end. Also they are hidden away so you'll never really see the wire anyway.

The first place is the side mounting brackets that the bottom arms pivot on. Just two bolts on each side. I bolted them up....again using loctite....and torqued them up to the factory specs.

Then it was a case of wiring them. My mate Brian had some safety wire pliers which he has kindly loaned to me....thanks Brian. Here's what they look like, and the wire is a stainless wire specifically for the purpose.

I searched on Youtube to find out how to use them and here is the clip I found most useful. If you have trouble viewing the video here, paste this link into your web browser to view. https://www.youtube.com/watch?v=IwkL0qfyFL0

So I had a crack at it and here is my first attempt. Looks okay and it will certainly do the trick. To loosen a bolt you need to turn it anti clockwise. As you can see here if you turn the left bolt anti clockwise (try to loosen it) it will pull the wire and try and pull the right hand bolt in a clockwise direction i.e. to loosen the left bolt the wire will try and tighten the right bolt....outcome is the left bolt can't come undone. Now try and turn the right bolt anti clockwise....same deal it will try and tighten the left hand bolt. Thats it a locking or safety wire doing its thing.

With that all done while I still had access to it, I was now able to start mounting up some of the other hardware. 

You might remember from my last post, with the set up I have, that I need to bolt the brake calipers on in their two separate halves. This is because the bolts that need to be tightened to hold them on will be behind the brake disc. So I can't put the caliper on and then the disk. Nor can I put the disc on then the caliper.

Instead I need to bolt the inner half of the caliper on to the mount bracket....then slip the disc on....then bolt the outer half of the caliper on.

Here you can see I have the inner handbrake caliper half slipped onto the mount bracket.

And here is the main footbrake caliper inner half mounted. Note also the drive hub is now bolted on too.

Here is a view of the whole set up just before I slip the brake disc on.

Once the disc was slipped I was able to bolt the outer caliper halves on which effectively clamp the disc in place.

And here we are all buttoned up! The brake pads have been inserted through the slot in the rear of the caliper and that is another step in the assembly process completed!

Pretty happy. Its starting to look good and you'll have to take my word for it, it looks 10 time better in the daylight!

Rear Axle - Jag Rear Overhaul - Part 7

Ok, we are really making progress in the right direction now. No more stripping of parts and pulling things to bits, its all finishing and reassembly now.

In the last post you will recall I had the final base coat all prepped ready for finished colour......well here it is. These first pics are of the diff head all painted in metallic silver so it should blend nicely with all the HPC ceramic coating, polished alloy, stainless and chrome.

This is how the paint came out straight off the spray gun. Its the first time ever that I have used a spray gun as I never had the gear. I splashed out a while back though and bought a reasonable compressor and an Anest Iwata spray gun. Pretty good items I am told and I have to say I was really impressed with the finish. Totally stoked for a first attempt apart from a couple of rogue sandfly's and a bit of dust.

Next step was to give a good coat of clear which I did soon after these pics. I left the sandfly's and the other two imperfections and came back to them next day. Firstly I sanded the whole diff head with 1200 grit wet and dry and got it ready for more coats of clear, then I sanded out the wee imperfections and touched them up with my airbrush. The silver went on pretty well and matched perfectly, so all good.

Then I broke out the Iwata again and gave it a good few layers of clear. Its amazing no matter how you go about painting the diff head you still seem to miss a bit, there are so many bumps crevices and angles! Not a worry though I'll do that one spot I missed with the airbrush tomorrow, but meantime this is what it came out like with the clear all but finished.

Again this is just straight off the gun so pretty stoked! I did have a bit of drama with the clear going all cloudy though. Quickly shot upstairs and googled that and found it was a temperature thing. Just too cold and the air was damp. The cloudiness is caused by moisture. A quick shot with my hot air gun to warm everything up and the cloudiness disappeared.

I have a couple of runs I'll need to knock back with sandpaper and that one wee touch up, but apart from that its probably good enough to get the final shine using a bit of cutting polish without any need for sanding, especially given it is just a diff head. As my mate Bill says, at least the possums and all other road kill will have a nice view of the car. Very happy indeed.

Actually while I'm talking about the view for road kill.....there is a big square plate that reinforces everything under a jag rear. A lot of guys just don't bother with this but I quite liked this custom one I found and started prepping that for a bit of paint too.

Here it is being masked up. I had the metal polisher shine the flames so I will just paint the background. In this next pic I am trimming the masking tape with a sharp knife.

Heres a close up.

And here it is all primed ready for a first sanding.

Another day dawns and after a couple more coats of primer its time for some colour.

And with the masking tape removed!

Lastly I wanted to add a bit more detail and I have to thank the late Steve Foster here! I first met Steve in October 2009 when I got my white 33 Coupe on the road. Steve had not long gotten his blue one on the road too and below is a pic of that day with the two cars parked side by side.

Steve was incredibly helpful to me with parts and advice for my Coupe and he would become one of the main reasons I joined the Mid West Street Rods club. Steve was a sign writer by trade until he became ill with cancer. That didn't stop him though, he went on to live life to the full, finishing several projects and applying pin striping to many vehicles, not least of which was his own 33 Coupe. You can see the detail on the boot lid in this next pic.

I was fortunate enough to watch Steve do some pin striping on Roger and Ange's 28 Chev sedan and to be able to quiz him for a few pointers and tips along the way. Following that I purchased a pin striping kit and have had a few practice goes. My efforts pale in comparison to Steve's but its fair to say I couldn't have done it without his typically generous attitude in imparting some of his knowledge. 

My first real attempt, apart from practices on glass, was this flame work I did on my Grandsons Pedal Car for Christmas last year. I think Jayden was pretty pleased with it!

Anyway back to the diff....I used my wobbly pin striping skills once more to give the bottom plate a bit more definition. It adds a nice touch I think.

Cheers Steve!

Rear Axle - Jag Rear Overhaul - Part 6

Can you believe it, I am finally getting some shed time again. We have had a really busy life in the past 12 months with major home renovations and repairs. It sapped all our money and our time too. In fact it is still going on but is coming close to an end.

In addition to that I went mad and got involved in road cycling. That takes a bit of time too but I am much better for it, having lost a heap of weight and getting some really good health results too...... actually that was until boxing day! Yes my blood results and reduced need for medicines is all good, but I thought I'd have a crack at mountain biking while on holiday and I came off. In the process I developed another health condition! I smashed my collar bone....no not just a break I smashed it! I am suffering for it still and can't lift a whole lot which again has impacted on shed time. Coming right now though....oh and the internet shopping and parts collection activities have been carrying on so there has been a bit of prep work going on in the background.

Anyway....today I got back onto the Jag rear, namely the diff head. In my last post about the diff I was sanding and painting the head. To date I have spent 45hrs doing that. Fingers have been blistered cracked and bleeding, but it does look pretty good so far.

Before sending the head away with all the new bearings, seals, an appropriate gear set and a limited slip unit, I painted the head in lacquer as this will be a base colour for the silver top coat but it also means the porous primer is protected from the oil and grease during the assembly process.

Its not easy assembling a jag diff and getting all the clearances right so I had to take it in to Diffs R Us to be rebuilt. Even then it cost an arm and a leg as it took him 13hrs to set that up and assemble the hubs. Don't try that at home!

So here it is in all its glory!

It looks pretty good all assembled with the polished brake mounts in place too. The claws out the front will hold the handbrake calipers.

Notice the countersunk screws that hold the shiny mount plate in place. These will soon be a cause for concern!

Once the brake discs go on I won't be able to put a bolt through the brake mounting plate and through the caliper itself, in the next pic you can see the hole is partially obscured here by the edge of the disc. So to overcome that I will need to put the bolts in before putting the disk on. That is a problem too though as I can't slide the calipers on while the disc is in place. Its okay though as the calipers are a 2 piece unit I will be able to split them. Bolt one side on to the mounting plate, then slip the disk on and lastly put the other half of the caliper on.

It means it will be a pain in the backside if I ever need to remove the disc as I will need to split the caliper and bleed the brakes when I reassemble, but that is probably not going to happen very often (if ever) as the back brakes don't do a heap of work and the car wont do too many miles.

Replacing brake pads will still be easy as they come out through a slot in the back.

In this next pic you can see what it will look like once the caliper is mounted. See how it grips around the disc. This is why I can't mount the caliper then put the disc on later. If you look carefully you can see a join down the centre of the caliper where the two halves come apart. That big rectangular opening in the back face is where the brake pads can be removed and replaced.

Here is a side view with the caliper not quite in position so you can see the mount holes.

Actually thats not quite true....its because the caliper wont quite fit yet. The caliper mounting points are about 2 mm too thick so the caliper would be sitting off centre if I plowed ahead now. That would not be ideal!

You can see in this next pic how the mounting lug on the caliper overlaps the mounting plate. Its only 2mm but enough to screw things up. I will get that 2mm machined off, then we will be good to go.

As you saw earlier the mount plate runs pretty close to the brake disc so there is no room to get a bolt head down in there, so I need to use these countersunk bolts. Once I countersink the holes they will sit down almost flush with the mounting plate. Here it is before.....

....and after.....

When I bolt the caliper on I will use spring washers and a locking nut so that there is no chance of this bolt coming loose and fouling the brake disc. It wouldn't be the end of the world if it did....it would just scrape on and probably damage the disc and it would make a horrible noise.

Remember though how I said earlier that I was concerned about the countersunk screws that hold the shiny mount plate in place. While these are countersunk and out of the way, they would be a real problem if one came loose. If you look closely in this next picture you can see the studs that go through the drive flange have a head on them (see the reflection in the shiny brake mount plate) and whats more they are directly in line the countersunk brake mounting plate screws. If one of those countersunk screws came loose it would hit the drive flange stud and stop that axle turning....now imagine what would happen if that occurred at 100kph. One rear wheel locking like that would be catastrophic!

I looked at the other jag diff I have here (now remember these don't have the same clearance issues as they don't use a shiny brake mount plate like I have made for the Wilwood calipers) and I remember now....the original bolts at that point are held in place with locking tabs.

Sooooo, back to the drawing board.

I don't feel I can effectively lock the countersunk screws so I will go for a traditional bolt and use a spring washer under them. I will also drill tiny holes through the heads of the bolts and wire them together. This is overkill but I want to be really certain about this.

Here are some sample pics off the web showing the bolts with their drilled heads and below that a pic of what they look like once wired up.

Another modification will be required though as I don't have room for a bolt head and a spring washer in between the brake mount plate and the flange studs, so I will need to recess them into the brake mount plate. All will be good, just more machining and more bolts required.

Lastly, here is the head all mounted up on a stand ready for me to apply paint.

Next time we should see paint and be able to put the unit back together again!