Rear subframe breakdown

The final major section to disassemble are all the parts which connect to the differential (or pumpkin in American). Having previously separated the IRS from the prop shaft, what remains to be removed are: the swing arms, two half shafts, opening up and checking the internal condition of the differential. 

The steps taken in this blog entry could not have been completed without two of my good friends Ian and Suvi Virtanen, who came up several times and spent the weekend helping out in the garage. Ian’s all rounded mechanical experience was, is and I'm sure will continue to be a massive help.

Half shafts

The half shafts are connected to the differential with four 11/16 nuts, through a thick spacer. To remove these nuts, I placed a spanner on the head of each bolt in turn, which I then wedged against the wooden pallet to stop the shaft from rotating. I then used my small upcycled breaker bar on the corresponding nut to loosen it. These did require a considerable amount of force for such a relatively small nut. With these nuts removed, as the bolts stay in place, the half shaft can be freed from the differential. In case the spacers (between half shaft and differential) are not symmetric, I decided to leave these in place on their respective sides by loosely putting back on the nuts. This should also help reduce the chance of me loosening them and the nuts.

Differential with one of the half shafts removed

The removed half shafts need to be further broken down into three components; differential mounting plate, half shafts, and splined hub ends. These three parts are connected together using two universal joints or UJ’s for short. Whilst the shafts go to AK for shortening, I need to retain either end for cleaning and painting.

Complete half shaft assembly prior to breakdown

Since I don’t have a hydraulic press or a large enough vice, the UJ are separated by brute force. The approach which Ian suggested was to place each UJ between a pair of sockets, one smaller than the central section and one larger. Then, with plenty of percussion persuasion, the joint cups began to slide within the gap. Unfortunately, there is not enough space between the shaft ends to separate the joint from its cup. Instead, the plan was to move one end of the UJ cap to its far extent and then use a drift or a sacrificial chisel to move the other end of the cap out by hitting it with a lump hammer. Similarly, you could also hit the UJ itself, depending on your future plans for them. With the two cups partially out, this created enough space between them for the joint itself to be removed.

Sockets used to drift out UJ cups

Repeating this process multiple times, all the UJ are finally removed. As I am not going to reuse these ball joints, I am not too worried about damaging the joint with the hammer or losing any of the needle bearings from within.

Separated UJ and differential mounting plate

Swing Arm Strip Down

Now the half shafts are removed and broken down, the remaining components connected to the differential can be removed. These are the square looking ring item around the front of the differential (apparently it’s called the Pendulum for some reason), the swing arms and the rear tie bar. These are all held together by some large bolts on the differential and another pair of fulcrum shafts.

This is becoming somewhat of a habit, but I again kept referring to another exploded diagram of the rear assembly to guide me through the process. 

Exploded diagram of the rear subframe Justjagsuk

The first part which Ian and myself removed was the Pendulum. The nuts holding this in place had already been removed by Simply Performance so it was just a case of leveraging this free. Unfortunately, the stiff bushes in the pendulum and the large contact patch on the diff bolts meant this required some long pry bars and considerable force to shift. We then discovered that the pendulum would not pass the plate on the input shaft, with the lower fulcrum shafts in place. 

The plan dynamically changed to pulling the rear tie bar and swing arm assembly in the other direction to separate it from the differential. As we removed this part we were greeted with a clunk as the pendulum also came free and fell onto the differential casing. We should have seen that coming, but no damage done. Now the pendulum easily slides over the input shaft bracket and away from the differential.

Differential after the removal of the swing arm and pendulum  

Swing arms connected to the tie bar with their fulcrum shafts

With the components removed from the differential, we had hoped to open it up and check its internals. Whilst the 6 smaller 1/2 inch mm bolts were easy to remove, there were two bottom bolts/shafts at the bottom which proved more troublesome. These two large bolts required a 30 mm spanner with a depth of approx. 100 mm. Even after a quick trip to Wicks to buy a large adjustable spanner and some percussions we could not shift these bolts. With these in place, we could not open the differential. A review of several other AK builder blogs (mainly Steve's AK blog), revealed the historical difficulty and some of the innovative solutions which others had used. Clearly, more tools and further research was required here so I will mark this as a problem for the future. 

Not wanting to stop, we continued to separate the swing arms from the tie bar and the fulcrum shafts. The fulcrum shafts, however, seemed to be rusted in place to either the tie bar or the swing arms. Due to the large horizontal void between the swing arm and shaft, it seems obvious to expect water to collect here, eventually rusting these parts together. Clearly, Jaguar either didn't see this or cared.

Having tackled a similar problem before at the front, the solution seemed obvious, cut them out! A quick phone call to AK, it was apparent that they no longer require the swing arms and so I was free to cut them up as I wished. Out came the angle grinder again and I began to cut slices into the swing arm to separate the fulcrum shaft from the swing arm. The second time around and with better access to the metal surfaces, this was an easy-ish job.

Cutting the fulcrums free from the swing arm

Partially removed lower fulcrum shaft

With all that said and done, I had two fulcrum shafts, two junk swing arms and a tie bar. A good weekend's work!

Front Suspension Breakdown

Having previously stripped down the front brakes, the final stage of dismantling the front subframe are the suspension components. I must confess that during this stage I did phone both Simply Performance and AK to check what I should be doing and how to do it. The solution involved the use of an angle grinder, so fun times ahead.

As with previous entries, I found a schematic on the just justjagsuk website very helpful as it explained how the components fitted together. This made pulling them apart easier - or at least I knew what to do, even if at first I wasn't able to...

Schematic of front suspension assembly from www.justjagsuk.com/catalogue

Front Wishbone Removal

A few nights before starting this process I did a precautionary spray of WD40 on all the nuts and bolts I could see, connecting suspension components together. A quick job that should hopefully make my life easier in the long run. Using my shorter upcycled breaker bar I loosened the M10 bolts which connect the two halves of the top wishbones together (through the top ball joint). This was so easy I couldn’t believe my luck so I carried on, easily loosen the top fulcrum shaft nut (19 mm) as well. The same story was true of the bolts connecting the bottom halves of the wishbone together as well. At this stage, I chose to only loosen all these bolts in case I needed the rigidity of the suspension when using a breaker bar. A trick I learned from pulling apart IRS splash shield as mentioned in my last post.

Front top and bottom wishbones connected to upright and subframe

Although I could loosen and remove the lower fulcrum nut (22 mm), I was not able to twist or remove the shaft itself. This does lead to the pointless hypothetical question, when does a bolt become a shaft??

My luck had finally run out, however having loosened all the other wishbone bolts, I decided to completely remove all the wishbones parts that I could.  With the easy wishbones removed, the top ball joint remains in place as well as one half of the bottom wishbone, which connects to the fulcrum shaft and the upright via the bottom ball joint. 

Remaining front bottom wishbone and upright

Despite trying for an afternoon with a hammer and several sets of different pullers, I wasn’t able to separate either the top or bottom ball joint from the upright. Getting very fed up, I decided that I will tackle these joints when the bottom wishbone is off the subframe and I have easier and better access to them. This calm decision was taken much later having given up in the garage for that day.

After repeating the above process on the other side I ran into the same problem, with the ball joints and the fulcrum shaft, so it was time to tackle this obstacle. Initially, I tried hammering and prying on the shaft but with no joy, so went to do some research with the help of Dr Google. The two main methods I found from the internet were using a hammer (which hadn’t work) or using a blow torch to heat and expand the surrounding frame and then hit the shaft with a hammer. Given the amount of metal, I needed to heat up most mechanics used an oxyacetylene torch for this, which I didn’t have.

Fulcrum shaft rusted into the subframe

One solution which I came up with was to cut the shaft out from the subframe, although realising that I would need to be very careful, as this shaft is required for the kit. Another concern with this approach is that I didn’t actually have an angle grinder. Luckily, I was able to borrow a friends (massive credit to Andrew Young) brand new angle grinder, so many thanks to him. Also on a side note, congratulations to him and his wife on the birth of their first new child. 

Removal of Front Fulcrum Shafts

A quick phone call to AK, to check this approach and they said that they (and I) didn’t need the fulcrum shaft end of the bottom wishbone, so to make life/access easier I could cut this lose from the shaft. I therefore carefully cut two slices through the wishbone bushes and then chiseled the metal cutout and bushes free from the fulcrum shaft.  This meant I could drop the wishbone away from the fulcrum shaft, leaving just the fulcrum shaft to be removed from the stubborn front subframe.

With the loan of an angle grinder, I could start cutting up the frame. To avoid cutting into the shaft I cut some exploratory slices in the upturned subframe a few cm’s away from the shaft. Bending back this subframe metal, I found that, to my surprise, it was filled with foam. With the foam removed, I could see the shaft and so could begin cutting closer to it removing the metal as I went.

Initial cuts into front subframe to avoid cutting the fulcrum shaft

Whilst making these initial cuts, it was amazing how quickly the angle grinder began to look oily and dirty. I did carefully clean the angle grinder once finished with white spirit before returning it.

Borrowed angle grinder - what a tool!!!

Having cut away much of the metal which covers the fulcrum shaft I learned that there is a metal sleeve surrounding the shaft. This makes life more challenging and so more careful cutting required… joys

Fulcrum shaft still within a metal cylinder

The process that I went through here was to cut the fulcrum shaft and its sleeve out from the rest of the frame. Due to the concave angles which surround the bolt head, I had to cut a large section out from the subframe which included the shaft ends, and then cut this section down afterward at my bench. With the shaft and sleeve finally removed, I now had to separate them. My suspicion was that only the ends of the sleeves were rusted onto the shaft. If this is true, I only need to cut the ends of the sleeve away. For this, I made very careful slices into the sleeve along its length and then one circumferential cut. With these cuts, I could then chisel the sleeve away from the shaft. Repeating this process on both ends of the shaft, the sleeve did then slide away. Lucky it was just the ends that had been rusted.

By only cutting small depths at a time, both shafts were extracted and more importantly are re-usable. This saves me a few hundred quid on buying a new set. Given the faf that I had gone to achieve this, I had to take a photo of the shaft placed back into the cutout of the subframe.

Front Fulcrum shaft, finally liberated!

Cutting out the Ball Joints

The one remaining item of the front corner to disassemble was separating the upright from the bottom wishbone half. After earlier removing the four 1/2 inch bolts and failing to separate the lower ball joints with either the puller and hammer approach and because I had had such fun using the angle grinder, I decided to slice the bottom off from the ball joint and its casing. Having cut the largest part of the ball away, the upright came free from the bottom wishbone half. Of course, this does still leave part of the bottom ball joint (and the top ball joint) in the upright, however, as AK will be refurbishing the upright, I will leave these there for them ... an early Xmas present.

Bottom wishbone with ball joint casing cut off

Final Thoughts

Having completely disassembled the front subframe and the rear hubs removed, the pile of parts is starting to mount up. 

Parts removed from donor chassis thus far