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!