Saturday, 12 January 2019

Body / Chassis Delivery Day

Delivery day for the body / chassis kit has finally arrived!!  It was a cold and grey day but thankfully not raining.

I spent the morning doing some final tidying of the garage and getting the exchange donor parts out ready to return to AK.  Note that AK now no longer need the rear wishbones as exchange items so it was just the front lower wishbones, stub axles / uprights and driveshafts that needed to be returned.

Exchange donor parts ready to go back

Noel, the AK delivery driver, was right on time; having advised he would aim to arrive between 1.30 and 2.00pm, he pulled up bang on 1.45pm.

What a glorious sight!!

I'd booked the assistance of a couple of friends, Richard and Paul, to help unload.  First task was to roll the body / chassis off the back of the trailer and onto the drive way.  Next was to remove the variety of parts that come with the kit, plus the extra parts that I had ordered, from the body tub where AK had loaded them for transport.  We also discovered some parts loaded in the boot later on (after lifting the body off....).

Lots of parcels in the body tub!

The body was temporarily bolted to the chassis with 4 bolts.  Once these were removed, the four of us lifted the body off the chassis and onto the waiting body support frame.

Something was not right...Despite my matching the AK factory frame measurements, the body did not sit right on the frame and the front cross member of the frame was nowhere near the front footwells in the body that were supposed to be sat on it.  

After a bit of head scratching we all concluded I would need to buy some additional bearers to sit under the floorpan - a job for later.

Next task was to lift the chassis into the garage and sit it on four axle stands (with a strip of old carpet to protect the freshly powder coated chassis!).

Chassis in its new home!

Then a quick trip to Wickes was in order to get some extra lengths of 63mm by 38mm timber studding and sort out the body support problem.

On return I realised what the problem was.  We had put the body on the frame with the rear support under the channel for the rear axle (which is how Stuart Holden had supported his body)

Stuart Holden's body support frame - rear support sits in channel for rear axle

Although my frame was based on Stuart's design, the measurements I had taken at the AK factory were based on the rear support sitting under the boot floor.  

Richard and I managed to lift the body up and forward on my frame and hey presto! now the body sat flat and the front footwells were sat on the front cross member of the frame.  There was still quite a gap under the rest of the body, and so the extra timber I had bought didn't go to waste and we added an extra crossmember to sit under the rear of the passenger compartment.  A bit of fine tuning with some pieces of thick corrugated cardboard was required to get all contact points supported on the frame.

Body sitting correctly on frame - additional crossmember added to support rear of floorpan




With that sorted, final job for the day was to stow all the bits and pieces under the chassis and wheel the body into the garage over the chassis (and it all fitted - just!)


Hurrah - it fits!!  There is even a bit of working space as well!

With body safely stored it was time to retire for a well earned beer.  Thanks to Richard and Paul for your help

Think I could be standing here for some time......

Wednesday, 2 January 2019

Christmas Holiday Projects - Body Support Frame

Despite being a bit behind with cleaning and painting the donor parts, with the AK body and chassis arriving early in the New Year I needed to get the garage ready to receive the kit.

My plan was to build a timber frame to store the body over the chassis; the idea being that the body/frame can be moved out of the garage to allow work on the chassis to proceed.  The idea came from another AK owner - Stuart Holden - and I have basically taken his frame layout as per the plans on his blog (although I did change some of the dimensions having taken my own measurements of the frame AK use to support their bodies in the factory).

General layout of body frame - courtesy of Stuart Holden

The AK body is supported at the front under the footwells and the kick-up at the rear sits under the boot floor.  The whole frame is wide enough to span over the chassis and sits on casters to allow it to be moved out over the chassis to allow working space.

I bought fourteen 2.4m lengths of 38mm by 63mm timber studding from Wickes, M8 coach bolts, coach screws (80mm and 60mm length) and washers from Namrick and some heavy duty casters from Screwfix.

Christmas Holiday project materials!

Timber cut to size

Fixings 

I started by making the two end frames.  All joints were bolted and glued for strength.  I then joined the added the sides and the diagonals - again all bolted and glued for strength.

I recommend checking constantly that all the elements are square and true (check once, check twice and check again) before and after fixing!.  Despite all my careful measuring and marking I did have to refix one of the diagonal bracings on the front frame, as although I checked the squareness several times before fixing, after fixing, one vertical was clearly out of plumb by a significant margin!! 

Front sub-frame completed...

...and rear sub-frame completed
Subframes joined, braced and casters fitted

The finished frame is nice and solid and hopefully be fit for the intended task (time will tell).  It does look suspiciously like a double bed frame - a point which my missus remarked upon and that it would be quite useful with all the time I would be spending in the garage...not sure what she is getting at!

It is a slightly snugger fit in the garage than I was hoping for so I will need to do a bit more rearranging to give a bit more room down the sides of the frame.  But a days work well spent I think!

Bit tight down the sides......

Early Christmas Present....

Over Christmas I am planning to build a frame to support the AK body while I work on the chassis.  I wanted to check the measurements of the frame that AK use to support their bodies in the factory when they come out of the molds so decided to pay them a quick visit just before Christmas.

When making the arrangements to visit, Carla told me that I must have been a very good boy this year as Santa had a surprise for me in the workshop!!!!

When I arrived at AK I was greeted by the obligatory cup of tea (and chocolates as it was the festive season), and then Wendi showed me our AK body in the workshop (excited) and then took me down to the powder coaters to see the chassis being finished off (even more excited!) - roll on Jan 11th 2019!!

My Gen III chassis fresh out of the oven!

AK body ready and waiting!

Friday, 14 December 2018

Bush Removal!

The title of this page should generate some internet traffic......

Since AK supply new suspension wishbones all round, there is no real need to remove any of the bushes from the front wishbones when stripping down the front suspension.

The only bushed parts that need to be reused are at the rear - being the "pendulum" and the wishbone tie, both of which support the rear lower wishbones and the differential unit.

I had assumed that new bushes would be required all round as a matter of good practice.  However as per my post on the rear suspension strip down I discovered that the bushes in the rear wishbone tie are a non-serviceable item (you can no longer buy them either separately or as part of a replacement wishbone tie part), so DO NOT REMOVE THESE BUSHES!!

So the only bushes that I actually need to replace are in the "pendulum" bracket.


Pendulum bracket

So what is a bush?  In simple terms (?!) it is a sort of vibration isolator found anywhere where there is a joint in the suspension system of a car.  They cushion the movement between two solid parts, helping to avoid shocks and vibration and making for a quieter and smoother ride.

The bushes as fitted to the Jag suspension are of the metalastic type, which consists of an inner and outer metal sleeve with an rubber core in-between.  They are also an extremely tight fit in whichever part of the suspension they are mounted and typically quite hard to remove, especially in older vehicles once rust and road debris have done their bit!

Although I did not need to remove the bushes from the front wishbones, I decided to have a couple of practice attempts in preparation for the rear pendulum.

I am fortunate enough to have a 10 ton hydraulic press in my garage which I thought would be man enough for the job and indeed on my first attempt one of the front wishbone bushes simply popped out with no problem what so ever.  The second attempt was not so successful; having cranked the jack on the press up to what I felt was worryingly close to breaking point, there was no sign of any movement.

Plan B involved using a hole saw with a suitable diameter to cut into the rubber between the two steel sleeves.  This allows the removal of the inner sleeve and then using a cold chisel and a large hammer, one end of the outer sleeve can be hammered inwards with freed the remains of the bearing sufficiently that it could be easily removed with the press.

The one draw back of Plan B is that it generates a lot of smoke and covered my working area with little globules of burnt rubber that stick to everything and are a pain to clean up...

New hole saw (left) - after bush removal (right)

I also found that all the bushes are slightly different sizes which would require the purchase of a large number of different diameter hole saws.  So I needed a Plan C.

In the end Plan C was much the same as Plan A, except that when I reached the point where I thought the press was going to break, I closed my eyes, protected my most valuable body parts, and cranked the jack handle a couple more times!

This generally resulted in an almighty bang - which thankfully was not the press breaking, but the bush shifting in the mounting, after which it pressed out relatively easily.

A naked bush!

Pendulum bracket with all bushes removed


Friday, 7 December 2018

Black Friday (Thursday?!) Bargain

Having slightly (?!) grazed the rear lower wishbone inner fulcrum shafts with my angle grinder while trying to complete disassembly of the rear subframe (Rear Axle Strip Down - Part 4, I had reconciled myself to the fact that I was going to have to buy replacement shafts.

Original fulcrum shaft - with "slight" nick
from angle grinder...!

I had previously checked that it was possible to buy these, and while they are available,  original or OE fulcrum shafts are not cheap!  When I checked SNG Barratt had OE items listed on their website at the time for just over £130 - EACH!!!  

This was going to be a significant dent in my planned expenditure.  However I have to thank another fellow Cobra builder, James, who having read my blog, got in contact to tell me that he had spotted that SNG Barratt had discounted the fulcrum shafts by £113 - so they were only £20 each!  

Needless to say I got straight onto the SNG website and ordered two - saving myself £226.  That's my Black Friday (Thursday) bargain for the year.  Excellent service from SNG; I ordered them yesterday lunchtime and they arrived today. Happy days!!


£266 worth of fulcrum shafts - for the bargain price of £40!




Project Snake goes Global!!

Sometimes the power of internet amazes me (and scares me in equal measure!).

Last weekend I was browsing Facebook and found the AC Cobra group page - which although mainly for owners of real AC / Shelby Cobras, is also open to owners of replicas and generally anyone with an interest in these amazing cars. Once my request to join the group had been accepted I posted an introduction to the group including a link to my blog.

Since then I have had just shy of 300 views to the blog - in less than a week!  The audience has been from all corners of the earth with views from US, Australia, South Africa and Europe and of course the UK.

So welcome to all those who have taken the time to visit my blog.  I hope its of interest and that you keep coming back to see how the project progresses.  I'd welcome any comments or feedback on the content (I'm a blogging newbie) and of course any tips / advice etc will all be grateful received.

I think I can say that Project Snake has gone global (but not viral....yet!!!!)

Thanks all.

Sunday, 2 December 2018

Rear Axle Strip Down - Part 4

The last major part of tearing down the rear axle / subframe was to remove the lower wishbones and fulcrum shafts from the wishbone tie.  This part of the rear subframe can be seen at the top of the photo below.  The 'pendulum' (the rectangular looking bracket at the left) was removed from the front of wishbone assembly by Simply Performance when they removed the diff for refurbishing.


Lower wishbone assembly (top)

As has become usual with stripping down the rear, this was not as straightforward an operation as I had hoped.

Firstly the lower wishbones have been designed so that they pivot on the fulcrum shafts only at each side, the middle section of the shaft is partially exposed to the elements and of course gets extremely corroded.  The engineer in me fails to understand why anyone would think this was a good design!!  The previous design of the XJ40 suspension appeared to have recognised this problem by having a spacer tube over the central section of the fulcrum shaft which at least (if properly greased) would give some protection to the shaft.  For some reason the later design made no such consideration. So the long and short of it was that the fulcrum shafts were well and truly rusted into the lower wishbones.

When I had helped fellow AK Cobra builder Richard with his body and chassis delivery, he had advised me that AK no longer need the wishbones as exchange items and that he had resorted to cutting the wishbones off the fulcrum shafts.  So I didn't bother trying any other method myself, I simply reached straight for my trusty angle grinder!

The first part of the operation to cut away part of the front of the wishbones was  relatively easy - some straight passes with the grinder and some assistance from a cold chisel and I managed to free up the front part of the fulcrum shaft.


Front sections of both wishbones cut away
Corrosion of fulcrum within pivot section
as well as exposed central section

Cutting the rear section of the wishbones was not quite so easy.  I was worried about damaging the wishbone tie (which needs to be reused) with the grinder so couldn't cut along the line of the fulcrum shaft.  Instead I tried to cut through the front section at an angle. 

Unfortunately this part of the wishbone is quite thick and of course is a solid casting and took a lot of grinding to cut through.  I was never imbued with a great amount of patience and on the first wishbone I managed to nick the fulcrum shaft with the angle grinder (actually it wasn't a nick, it was a bloody great gouge....).

Deciding that this shaft was now effectively scrap (and having checked that I could actually source a replacement one) I simply cut the end of the fulcrum bolt to free the wishbone from the tie.  I then managed to hammer the shaft out of the wishbone.


One scrap fulcrum shaft...

The other side was slightly more successful.  I managed to cut the front of the wishbone at a slightly better angle which meant that I was able to hammer the wishbone off the shaft without resorting to butchering the fulcrum shaft (although I will probably buy replacements for both sides having knackered one side).


Ironically I could have done this much more easily.  When Simply Performance removed the diff from the subframe, they also removed the two bushes in the wishbone tie that the diff mounting bolts pass through.


Wishbone tie with diff mounting bushes removed

These bushes are not available as a replacement part.  In fact bizarrely neither the inner or outer bushes on the wishbone tie are available as a replacement part (several fruitless internet searches eventually confirmed this - although the bushes for the pendulum which mounts the front of the diff are all available!) and neither is the wishbone tie itself.

Ben at Simply Performance was happy to provide a replacement wishbone tie free of charge (as part of their guarantee that all parts can be refurbished) - he also sent me a set of spacer tubes (from the old style XJ40 rear suspension) as I had noticed in the AK build manual that these are required.

Replacement Wishbone Tie (middle) with
all bushes present and correct!!  XJ40 fulcrum
shaft spacer tubes supplied by Simply Performance

So for fellow builders out there - when you do manage to separate the rear wishbone tie DO NOT ATTEMPT TO REMOVE THE BUSHES!!  

So of course I needn't have been so careful in cutting off the rear part of the wishbones to try and protect the wishbone tie, as mine turned out to be scrap in any case.....

Oh well - all the main parts have now been stripped down.  Now to clean, derust and refurbish all parts that are going to be reused.

An exploded rear end!!