3-Dec-2009

 

Finally all the parts have arrived. In the end I bought the Vitesse 1600 caliper mounting ring along with an up-rated front alloy hubs from Canley Classics. Amazingly the items fit together without too many major issues. The biggest problem so far is the alloy caliper bracket fowls the vented disk, however a couple of minutes with a junior hacksaw and a file I have managed to remove a small section of the bracket and now every thing fits together without any problems. I have also discovered a couple of other issue with the hubs that isn’t mention with the instructions that accompany the hubs. The first thing is you ideally need to use longer bolts to attach the brake discs to the hub. If this is done there will be less chance of you stripping/damaging the threads in the alloy hub. The other issues is the bolts that hold the steering arm in place have to be in a certain position or they will also catch the outside of the ally hub causing damage. There are still some outstanding issues that I need to complete such as modifying the dust shields so they can be used with the new calipers (I could leave them off but I want the car to look as original as possible). Once this is done I just need to paint all the parts and reassemble the front suspensions.

caliper_mounting_braket

 

 

4-Nov-2009

The overdrive and gearbox rebuild is complete. I have also managed to swap the rebuilt gearbox with the one originally fitted to the Marcos car. This turned out to be easier than I expected as it’s actually possible to swap the gearbox without having to remove the engine. To do this you will need access to a ramp or pit and the help from another person. If you want to do this step 1 is to remove the prop shaft. Step 2 remove the 5 bolts that attach the cross member to the car and gearbox and also remove the speedo cable. Step 3 remove the gear lever, Step 4 undo the 6 bolts that hold the gearbox to the bell housing. Finally step 5 with the help from someone else carefully lift the gearbox from the car tacking care to disconnect the wires from the overdrive inhibitor switch. Till you manage to refit the gearbox don’t let anyone press the clutch pedal or you will never get the replacement gearbox to fit. I still need to take the car for a test drive to check the operation of the gearbox/overdrive but this will have to wait till I have finished the upgrade on my front brakes.
Since first completing the Marcos and taking it out for a drive this summer I have never been very happy with the brakes, I find it almost impossible to lock the brakes up no matter how hard I press on the pedal. Due to this I have been researching what brake upgrades are available for the Marcos. There are a lot of kits available but one of the main criteria I had was that I still wanted to be able to keep the original Marcos alloys(13″ Rim). In the end I chose the following kit from Caterham cars. This kit is designed for a Caterham car and is made by AP Racing so it should be the best money can buy. It should also fit the Marcos as the Caterham front suspension is based on the original Triumph Spitfire upright. This means that so long as you swap the caliper mounting ring for the one from a Triumph Vitesse 1600 everything should bolt together straight out of the box.
The only parts to arrive so far is the kit from Caterham and I’m still waiting for caliper mounting ring to arrive from Canley Classics. Till I get this part I won’t know for certain that everything will fit together. I have tried fitting the vented brake disc to the GT6 hub and this is a perfect fit so now I just need the caliper mounting ring to see if the caliper fit.

ap_brakes

28-Oct-2009

The overdrive is 75% complete however I’ve encountered a couple of issues. The first one was the prop shaft bushing that’s mounted in the rear part of the overdrive housing was badly worn and needed replacing. It turns out this part is no longer available but I was able to find a suitable replacement at a local bearing company (only cost a fiver). The only problem with the replacement part is that the external OD of the bush is slightly bigger so I’ve had to take the aluminum housing to the local machine shop to have it bored out. Once this is done I will be able to have the new bush pressed in.
The other issue is that I’m missing a couple of orings that are required for the main operating pistons. It turns out the pistons in the overdrive fitted to the Marcos car is slightly different to the majority of LH type overdrives (eg the ones fitted to MGB’s). The pistons are made from two pieces. This means an extra oring is required and its not supplied in the rebuild kit as standard. When I phone an Overdrive specialist they told me they never normally replaced the orings as it was almost impossible to get the pistons apart. They basically said that if they had a problem with the seals it was cheaper and easier to just replace the whole piston with a solid one, however they didn’t currently have any pistons available for sale.
As the seals in my pistons were not sealing i had no option but to try and dismantle the pistons which i have managed to do so now all I need to do is visit the local bearing company tomorrow and buy a couple of replacement orings

25-Oct-2009

A very successful weekend. The gearbox has been put back together and now all that’s left is to make a start on the overdrive. The covers of the gearbox still need to be removed one last time so the gaskets and oil seals can be fitted but I wanted to make sure the selector mechanism worked before I did this. The other issue left is I still need to buy the correct oil seal for the front of the gearbox as the one supplied in the overhaul kit was the incorrect size. This shouldn’t be a major problem as a bearing company in Norwich stocks them and while I’m there I will also need to get a replacement bearing for the overdrive as one of them feels a bit worn.
Hopefully if all goes well I can get the overdrive back together tomorrow afternoon.

overdrive_parts

rebuilt_box

 

23-Oct-2009

Spent the day stripping down the gearboxes and overdrives. Overall this was relatively easy job and the only difficulty part was dismantling the gears on the main shaft. The problem was the shaft from the Type 5 gearbox was too long so it was impossible to use a bearing/hub puller to remove the bearing so the individual gears could then be removed. To overcome this the only option left was to pop down the local machine shop and use their hydraulic press (cost me a fiver). Once the gearboxes was stripped I gave the items a quick clean so I could check the condition of the parts. The parts will still need to be cleaned more thoroughly before I can start reassembling.

The selection of parts can be seen in the photo below, hopefully I can remember how it all goes back together!

lots_of_parts