Lotus Elan Central

CV Joint Split Boot Replacement


The reasoning behind my choice of the split boot kit is straight forward enough. I really didn’t fancy the removal and replacement of the drive shaft and I had heard about these split boots and was intrigued to give on a go.

The entire operation was carried out with the front side of the car raised and blocked. All work was done with the brake disc and calipers in place on the car…effectively the only thing removed from the car was the wheels.

The kit was purchased from these people: The kit includes: Boot, Grease, Adhesive, Scalpel, inner and outer Tie-wraps, rubber gloves and pretty good instructions.

Tool required for the job (over and above those supplied with the kit) were as follows (Fig 1 refers): Drip tray, rubber gloves (more than the single set supplied with the kit), wire clippers, pliers, junior hacksaw, hammer, cloths, craft knife and small flat head screwdriver

splitboot image 1
Fig 1

Once I’d removed the wheel I remembered just how little space there is to operate round the inner boot. Some exploratory tugging and probing was carried out but it was obvious that the old boot had to be cut off. I snipped a couple of knicks in the
convex parts of the concertina and then thrust the screwdriver into these holes to try and make them larger without much effect. So I changed tactics and attacked the smaller outer tie wrap at the conical end of the boot.

Note: At this juncture it’s worth mentioning that you will need the drip tray in place for the next step. I was amazed how runny the grease had become (does it break down or something?), and it goes everywhere.

This smaller tie wrap can (with some effort) be persuaded off the rubber and once free needs to be cut or sawed to remove it from around the drive shaft. Then insert the flat headed screwdriver between rubber and drive shaft and prise it open enough to attack the edge with the snippers and after a while you can snip fairly easily up the entire length of accessible boot. You should know have a well-butchered boot still firmly attached by its large inner tie-wraps and grease all over the place (Fig 2 refers).

splitboot image 2
Fig 2

As you can see, the whole boot gets covered in grease and is a complete swine to handle. You need to concentrate on getting a small piece of the rubber from under the tie-wrap. I prised and hammered the screwdriver (from both sides) between the tie-wrap and flange until I eventually managed to free the smallest bit of rubber which I held in place by putting the screwdriver through it and snipping it thus freeing the remaining trapped rubber.

Note: This step took the vast majority of the time. Half way through, without having made any noticeable progress I turned to the instructions to see if I’d missed any “Top Tips”. The instructions sum it up in four words…and I quote “Remove the old
boot”…a great help! I didn’t expect the old boot to be so very hard to remove…there’s probably an easier way, but I didn’t find it. Obviously it would facilitate the entire operation if the car was on a lift.

The boot and clip can then be slid down the drive shaft. The boot will separate from the clip and the clip then needs to be sawn through to get rid of it. The next step is to thoroughly clean all parts. I stopped short of using a de-greasing spray but I spent several minutes with clothes cleaning all and sundry. The instructions stress the need to avoid contaminating the new boot when applying the adhesive. Once cleaned, the joint looks like so (Fig 3).

splitboot image 3
Fig 3

Note: I wasn’t expecting to find this rather larger nylon washer inside the boot. I assumed it was to aid the retention of grease within the immediate confines of the joint rather that having it spill into the boot. I hope that’s what it’s for because that’s what it’s doing now!

The next step is to cut the new boot to as good a match as possible to the old. The instructions say to measure the diameter of the old boot etc…I couldn’t see an easy way of doing this then I remembered my dad’s old engineering tools and Hey Presto! Calipers. You won’t need these, because I’ve recorded the measurements. The large diameter is 81mm (Fig 4) and the small 28mm. The instructions have a cutting guide included (surprisingly, there no mention of the Elan size) but we equate to a B3 cutting comparison. Use the scalpel provided to carefully cut at the appropriate marks (Fig 5 refers).

splitboot image 4
Fig 4

Note: On the rear of the instructions the more common cars are listed with the cutting criteria as a guide. B3s include All Mazda models except 626 2.0ltr, All Mitsubishi models except Sapporo rears and All Vauxhall/Opel models except Ascona and Kadett. This may be of use for equivalent complete boot procurement.

splitboot image 5
Fig 5

You now need to assemble to new boot around the drive shaft. Start at the narrow end and glue the two edges together in 20mm increments. You need to hold each section together for about a minute so don’t make the sections to big and don’t even dream of trying to glue the entire seem in one go, you’ll never do it.

Eventually you’ll end up with a complete boot that can easily be pushed up and down the drive shaft. Now is the time to fill the joint. Cut a corner off the grease sachet and squeeze it into the housing. It stays in place easily…unlike the old grease!

TOP TIP Don’t be tempted to use the nylon washer as a grease dam. I did this at first and had terrible problems trying to get the large end of the boot over the flange to apply the clip. The trick is to work the washer into the boot end (once the adhesive has set the boot’s easily stretched and manipulated) and seat it in the second convex concertina.

Now push the entire boot over the joint. The first concertina can fairly easily be stretched/seated over the flange by pushing and rotating using a little bit of effort. Once it’s seated secure the small outer and then the large inner tie-wrap. It should then look something like Fig 6.

splitboot image 6

Note: If the large end is not seated properly, when you tighten the tie-wrap it will ride down the conical boot and over-tighten. You’ll then have to cut it off and go to your nearest workshop and scrounge another one… I know…I was that scrounger!

My final quote from the instructions is…””If you removed the wheel and brake calipers put them back, then lower the car”. Bugger, I knew I’d forgotten something!

- by Simon V.

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