As seems to be the way, I have had a bit burst of enthusiasm for the XJS the last couple of months.
With the rear suspension in the car, I was able to measure up for a driveshaft. I had it made by Denny's Driveshaft in the US. All the local driveshaft guys wanted to tell me what the driveshaft had to do- they all wanted to have half the slip yoke hanging out and build it out of 3" tube for example. It told me they had no idea!
Considering I want this car to be reliable and at least as refined as new, I went with Denny's. They provided everything from the slip yoke to the differential flange, assembled with premium Spicer long life universal joints. I can't say enough good things about Denny's, the whole process was simple and they replied to my emails very quickly. The result was a perfect fitting (and great looking) driveshaft, made on the other side of the world and in my hands within 14 days of order:
Once the driveshaft was trial fit and confirmed, it was out with the rear suspension cage.
I pulled the extension housing off the TH700 trans to change to a mechanical speedo gear, change the speedo ratio, replace the rear seal and replace the driveshaft yoke bush. There's no point running a nice new driveshaft with an old bush, the slop wears the slip yoke quickly, and the play makes the rear seal leak.
I used some online calculators to arrive at the correct speedo gears, I also took a guess at the revolutions the Jaguar speedo should turn (there is an industry standard that this model Jaguar may conform to, or not, we'll see!).
You can see the speedo gear here in green, it is held onto the shaft by being a tight fit and also by a spring clip which engages a hole in the output shaft.The gear selector lever also looks like it will work perfectly with the TH700 transmission, the speedo cable is a drop in to the TH700, luckily GM kept many things the same on the TH400/TH700!:
Once the extension housing was done and reinstalled, I pulled the rear end out of the cage and set to work
removing the rear brakes, output shafts etc. There's no point being this close to the output shaft seals and not replacing them. I'm currently waiting for seals and crush sleeves for the output shafts and pinion shaft:
A word of warning: the differential as you see it above, weighs 71ks. Do not even try and lift it unless you know exactly what you are doing, use a hoist, jack or a friend. I am used to lifting very heavy weights and due to it's shape, it was all I could do to just barely get this thing onto the bench- I had nothing left to give!
Of course, to get to the pinion seal, the centre section and ring gear need to come out. I don't get why people say Jaguar rear ends are weak, look at the size of the thing:
The output shaft bearings I already have, they are identical to a very common front wheel bearing on a very popular car here in Australia. Easy choice, bearings to fit "Jaguar" at $20+ each, or premium Koyo Ford Falcon inner wheel bearings at $9.50 each!
Here I am using the press to knock the shafts out:
I also have a cast aluminium differential cover to go on to help dissipate heat and a couple of metal brake shields off another car I am hoping to modify and fashion to fit between the rotors and differential on the Jag, to reduce radiant heat moving into the differential in the hopes of a longer service life from the seals.
The battery tray has also received some attention. Acid had created a corrosion issue. I didn't want to buy a new tray or cobble up some aftermarket piece, so as the stock one was still structurally very sound, I ground/wire wheeled out all the rust I could get to, soaked the whole tray in a mild alkaline solution to neutralise any acidic corrosion still going on, then laid in 4 layers of 6oz chopped strand mat and polyester resin. More than strong enough and acid proof!
Luckily no one sees the underside once the tray is in. The white bits are left over masking tape that need to come off. I masked all the holes over from underneath so I had a firm surface to work with when laminating:
I was in a fortunate position to have two fuel tanks to choose from. My better half gave me a really handy borescope camera for christmas, so I used it to peer inside and see which of the tanks was in better condition. Internally, they were almost identical, with surface corrosion but no major issues.
I chose the one out of the parts car as the black tank I had out of the current car had been repair ed in some way along the bottom.
After I stripped the green parts car fuel tank, I found out why the black tank had been repaired- the fuel tanks rust from the outside in! The tank was chemically stripped of paint, sanded then treated with phosphoric acid in preparation for the epoxy and after that the epoxy etch primer.
This epoxy is used as an internal tank liner for leaking tanks. It sticks like mad to coarse steel and pitted, rusty steel. Of course, nothing sticks to loose, scaling rust, so as with anything, preparation is key. The tank also received a coating of the eopxy internally to the base of the tank. The white patches are some epoxy filler over the few small pinholes the tank had.
I was surprised how much the single layer of woven rovings stiffened up the base of the fuel tank. With the bad corrosion it had, it was quite soft and would oil can readily when pushed, the rovings stopped that completely. I used the rovings just to give the resin more body and to prevent the resin layer from cracking, but the extra stiffness was a huge bonus.
This is after the bottom of the tank received a layer of woven rovings and phenol novolac epoxy resin. If you look closely, you can see the outline along the edges where I've sanded the edge of the fibreglass back.
And this is the main and surge tank just after stripping:
Whilst the rear end was out, I cut and fitted some heat shielding. The product is called Zero Clearance, it has a heavy embossed aluminium face, then an insulating layer of fibreglass and ceramic mat, then an ultra strong adhesive. I'm using it as a substitute to the stock, heavy, bulky, FLAMMABLE masonite and fibreglass shields. The Zero Clearance, as the name suggests, can be used with no air gap if necessary although in practice, an air gap is easy to achieve. The makers claim it can also briefly withstand naked flame, which it should be able to with the solid aluminium face. I really like the stuff.
It is super easy to work, cutting with shears or a sharp knife (several passes needed) works very well. I've used a few washers and rivets in strategic places to keep it in place, the adhesive is great, but a few extra fasteners never hurt:
The rear suspension cage was also pretty warped. Remember, this cage came from the donor car which had previously had some sort of engine swap. There were obvious signs of it having a hard life, with some serious buckling here and there. None of the edges of the cage were straight and there were a couple of small cracks developing near some of the cut outs. Most alarmingly, a crack had developed out of one of the four top bolt holes securing the differential to the cradle. Bent flanges:
The way the cage has bent has clearly reinforced my belief that the front of the cradle wants to rotate and climb upwards under hard acceleration, the cage had warped and bent in that direction. So I decided to straighten the cage and reinforce it with some 20mm, 3mm wall angle.
The process was simple enough- cut the angle and trim it to fit around the various places, then starting at one end, tack weld, then clamp along the flange, heating, bending and whacking with a mallet as I moved along the flange. It has worked very well, The cage has now gone from being 50mm too narrow across the bottom plate opening when relaxed, to spot on. Cage stiffness is also WAY higher, with only about 25-30mm of flex when separated across the bottom by hand, previously I could easily open it 150mm:
The repair looks fairly neat which I really wanted. I need to open up the small cutouts around the lower plate and control arm pivots a little with the die grinder, but overall has been very successful. I'm in the middle of deciding what to do with the bottom plate as it is as badly warped as the cage was. I want to run a torque link forward off it to the floor pan, I'm currently designing a bottom plate to have laser cut, it will be about 4-5mm steel so it is strong and can be welded to. A side bonus is to use it as a jack point.
The half shafts have also been rebuilt, but no photos of them yet. I wire wheeled them free of all paint and they have new UV joints in them now. The hub ends have been left off to ease rebuilding of the hub carriers, all the half shafts need now is a final clean and paint, but that can wait till I have other parts to paint.
I'm still undecided as to whether I should reinforce the lower arms, Aston Martin deemed it necessary and the racers swear it makes the car more stable. I'll think about that!
With the rear suspension in the car, I was able to measure up for a driveshaft. I had it made by Denny's Driveshaft in the US. All the local driveshaft guys wanted to tell me what the driveshaft had to do- they all wanted to have half the slip yoke hanging out and build it out of 3" tube for example. It told me they had no idea!
Considering I want this car to be reliable and at least as refined as new, I went with Denny's. They provided everything from the slip yoke to the differential flange, assembled with premium Spicer long life universal joints. I can't say enough good things about Denny's, the whole process was simple and they replied to my emails very quickly. The result was a perfect fitting (and great looking) driveshaft, made on the other side of the world and in my hands within 14 days of order:
Once the driveshaft was trial fit and confirmed, it was out with the rear suspension cage.
I pulled the extension housing off the TH700 trans to change to a mechanical speedo gear, change the speedo ratio, replace the rear seal and replace the driveshaft yoke bush. There's no point running a nice new driveshaft with an old bush, the slop wears the slip yoke quickly, and the play makes the rear seal leak.
I used some online calculators to arrive at the correct speedo gears, I also took a guess at the revolutions the Jaguar speedo should turn (there is an industry standard that this model Jaguar may conform to, or not, we'll see!).
You can see the speedo gear here in green, it is held onto the shaft by being a tight fit and also by a spring clip which engages a hole in the output shaft.The gear selector lever also looks like it will work perfectly with the TH700 transmission, the speedo cable is a drop in to the TH700, luckily GM kept many things the same on the TH400/TH700!:
Once the extension housing was done and reinstalled, I pulled the rear end out of the cage and set to work
removing the rear brakes, output shafts etc. There's no point being this close to the output shaft seals and not replacing them. I'm currently waiting for seals and crush sleeves for the output shafts and pinion shaft:
Of course, to get to the pinion seal, the centre section and ring gear need to come out. I don't get why people say Jaguar rear ends are weak, look at the size of the thing:
The output shaft bearings I already have, they are identical to a very common front wheel bearing on a very popular car here in Australia. Easy choice, bearings to fit "Jaguar" at $20+ each, or premium Koyo Ford Falcon inner wheel bearings at $9.50 each!
Here I am using the press to knock the shafts out:
I also have a cast aluminium differential cover to go on to help dissipate heat and a couple of metal brake shields off another car I am hoping to modify and fashion to fit between the rotors and differential on the Jag, to reduce radiant heat moving into the differential in the hopes of a longer service life from the seals.
The battery tray has also received some attention. Acid had created a corrosion issue. I didn't want to buy a new tray or cobble up some aftermarket piece, so as the stock one was still structurally very sound, I ground/wire wheeled out all the rust I could get to, soaked the whole tray in a mild alkaline solution to neutralise any acidic corrosion still going on, then laid in 4 layers of 6oz chopped strand mat and polyester resin. More than strong enough and acid proof!
Luckily no one sees the underside once the tray is in. The white bits are left over masking tape that need to come off. I masked all the holes over from underneath so I had a firm surface to work with when laminating:
I was in a fortunate position to have two fuel tanks to choose from. My better half gave me a really handy borescope camera for christmas, so I used it to peer inside and see which of the tanks was in better condition. Internally, they were almost identical, with surface corrosion but no major issues.
I chose the one out of the parts car as the black tank I had out of the current car had been repair ed in some way along the bottom.
After I stripped the green parts car fuel tank, I found out why the black tank had been repaired- the fuel tanks rust from the outside in! The tank was chemically stripped of paint, sanded then treated with phosphoric acid in preparation for the epoxy and after that the epoxy etch primer.
This epoxy is used as an internal tank liner for leaking tanks. It sticks like mad to coarse steel and pitted, rusty steel. Of course, nothing sticks to loose, scaling rust, so as with anything, preparation is key. The tank also received a coating of the eopxy internally to the base of the tank. The white patches are some epoxy filler over the few small pinholes the tank had.
I was surprised how much the single layer of woven rovings stiffened up the base of the fuel tank. With the bad corrosion it had, it was quite soft and would oil can readily when pushed, the rovings stopped that completely. I used the rovings just to give the resin more body and to prevent the resin layer from cracking, but the extra stiffness was a huge bonus.
This is after the bottom of the tank received a layer of woven rovings and phenol novolac epoxy resin. If you look closely, you can see the outline along the edges where I've sanded the edge of the fibreglass back.
It is super easy to work, cutting with shears or a sharp knife (several passes needed) works very well. I've used a few washers and rivets in strategic places to keep it in place, the adhesive is great, but a few extra fasteners never hurt:
The rear suspension cage was also pretty warped. Remember, this cage came from the donor car which had previously had some sort of engine swap. There were obvious signs of it having a hard life, with some serious buckling here and there. None of the edges of the cage were straight and there were a couple of small cracks developing near some of the cut outs. Most alarmingly, a crack had developed out of one of the four top bolt holes securing the differential to the cradle. Bent flanges:
The way the cage has bent has clearly reinforced my belief that the front of the cradle wants to rotate and climb upwards under hard acceleration, the cage had warped and bent in that direction. So I decided to straighten the cage and reinforce it with some 20mm, 3mm wall angle.
The process was simple enough- cut the angle and trim it to fit around the various places, then starting at one end, tack weld, then clamp along the flange, heating, bending and whacking with a mallet as I moved along the flange. It has worked very well, The cage has now gone from being 50mm too narrow across the bottom plate opening when relaxed, to spot on. Cage stiffness is also WAY higher, with only about 25-30mm of flex when separated across the bottom by hand, previously I could easily open it 150mm:
The half shafts have also been rebuilt, but no photos of them yet. I wire wheeled them free of all paint and they have new UV joints in them now. The hub ends have been left off to ease rebuilding of the hub carriers, all the half shafts need now is a final clean and paint, but that can wait till I have other parts to paint.
I'm still undecided as to whether I should reinforce the lower arms, Aston Martin deemed it necessary and the racers swear it makes the car more stable. I'll think about that!
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