Marina 5 Speed Installation
I previously described the assembly of the Marina bellhousing and Ford gearbox; this page looks at the work required to install the gearbox into the car.
The information below breaks down into the following headings
Mate to engine
Similar to my previous overdrive conversion, the Marina gearbox crossmember does not line up with the Ford gearbox mounting point. As I already had used the Ford Sierra gearbox crossmember in the overdrive conversion due to its offset and depth, I offered it up and hey presto it fitted first time, although it was a little low. The Ford rubber bush was required to support the gearbox correctly, replacements can be found from Ford specialists and Quinton Hazell under part number EM680. The replacement bush can be bolted to the crossmember with M8 bolts and locknuts.
There are two options to mount the crossmember,
Option 1 - bolting to existing Marina crossmember mounting points
Option 2 - bolting directly to the Marina floor plan.
The decision is yours; the difference between the two is that with Option 2 your must first cut the Marina gearbox crossmember mounts off the Marina body shell as they will get in the way, making it difficult if you wish to reinstall the original Marina gearbox at some future point.
Option 1 The Sierra crossmember is too wide for the Marina mounting points and the nearside will collide with the exhaust system, requiring the outside flange to be cut off the crossmember. I made some mounting plates to sandwich between the body mounts and the crossmember and new mounting holes drilled in the Sierra crossmember. I made the mounting plates from 3mm steel with folded edges for greater strength see pictures below.
Option 2 The Marina mounting points are cut off flush with the under body and the Sierra crossmember is offered up to the floorpan and new mounting holes are drilled in the floor pan see pictures below from Ben Claytons Zetec and Type 9 gearbox conversion. Strengthening plates should be added to the inside of the body shell to support the weight of the gearbox, I would think that a minimum of 3mm steel should be used for this.
With either option it may be necessary to shim the crossmember to present the gearbox output shaft at the correct angle to the propshaft; the first universal joint should have the minimum amount of work to do as possible. With option 1, the gearbox was too low, requiring packing washers to be inserted between the crossmember and the mounting bush. With option 2, the gearbox tail shaft may be too high, requiring packing washers between the gearbox crossmember and the body shell.
The Marina propshaft cannot be used in its current form as the Ford gearbox is longer than the Marina and it uses a splined fitting rather than traditional bolts. Once again there are two options, depending on whether you want to retain the Marina two piece propshaft arrangement or not.
Option 1 ask your propshaft specialist to cut and modify your Marina propshaft and mount a Ford splined section onto the front UJ. The new propshaft will need to be several centimetres shorter than the Marina one and will require rebalancing before fitting. You should ask your company how they would like you to measure the required new length. Reco-Prop in Luton asked for the distance from the middle of the centre bearing mounting points to the back face of the gearbox tail shaft (approx. 515mm), they then calculated the correct dimensions and fitted the splined unit their charge was around £130 (Spring 2009).
Option 2 do away with the Marina two piece propshaft entirely and have a single propshaft made up. With this version the critical measurement will be from the gearbox tail shaft to the differential face plate. Your propshaft specialist will require the tailpiece from the Marina propshaft to mate to the Marina differential. This version may cost more than option 1, but it will delete the need for a good Marina centre bearing. Ben Clayton chose the single piece prop.
When fitting either propshaft, you will find that 10-20mm of the splined shaft will be showing between the gearbox tail shaft and the first UJ, this is to take up for and aft movement of the engine and gearbox under braking and acceleration.
The Ford gearstick will come up through the transmission tunnel over 100mm closer to your driving position than the Marina gearstick. I trial fitted the gearbox and marked where where I wanted to cut the transmission tunnel. The picture below (below right) shows the rear edge of the Marina gearstick hole on the left and the rough cut of the new hole before finishing.
You will need to plate over the existing Marina gearstick hole. If I had a standard transmission tunnel I would have made up a plate with 1mm sheet steel, using the Marina plate as a former including the screw holes. This could be welded, screwed or pop-riveted into position. As I had previously modded the tunnel for the overdrive conversion, I had to make a custom plate which I riveted in place.
Gearstick & Cover
It is possible to re-use the Marina gearstick gaiter if you wish, with a new securing plate or bend the Marina securing plate to fit and drill pilot screw holes. You will find that the Ford gearstick will clash with the Marina handbrake if 2nd or 4th is selected whilst the handbrake is set. It is possible to cut down the gearstick and re-tap it to allow clearance with the handbrake lever. You can also straighten the bend in the Sierra gearstick. Alternatively, dont drive with the handbrake on!
Instead of replacing the standard gearknob shaft, I fitted a polished demountable shaft section from a 'quick-shift kit' and fitted an MGB 'gear stick grommet' bought for about £4.00. Once again this will go nicely with the carpet once fitted and I may use the MGB leather gaiter and chrome trim to finish it off at some point. At the moment I like the shiny gear stick look.
Just a note here, Brian did a good job straightening the stick for me and because I have fairly long arms, I can reach the gear knob in all gears. The unmodded Ford stick has I guess about a 30-35 degree angle set into it; rather than straightening it fully, some people may consider reducing the angle to about 10 degrees to bring the gear knob slightly closer to hand, but still miss the handbrake lever - its a personal choice I guess.
You will need to cut the Marina Carpet where the new gear stick comes through and also arrange to patch the carpet where the old hole was. You may consider using a centre consol to cover the old hole, I am using new carpet and will cut a hole to suit the car.
The Ford reversing switch will need a short loom making up as the connectors are different from the BL ones. If possible find a length of reverse light switch loom complete with the Ford socket from a scrap yard. I couldn't find one so I used shrouded electrical bullet connectors (red shrouds) which fit onto the reversing switch terminals and made up a short loom to connect into the Marina wiring loom.
You will need a special speedo cable, thankfully the Marina & Sierra share the same speedo head fitting (standard Smiths Instruments) although they look slightly different, it means that you can specify a speedo cable with Ford fittings at both ends. The Ford gearbox end uses a circlip to secure the cable to the drive output on the right hand side of the gearbox. The speedo output is on the offside rather than the nearside as on the Marina, the bonus is that you can run a shorter cable than the Marina and it is on the opposite side to the exhaust system. I used a specially made cable with a 1620mm (64" approx.) outer as this gives good easy bends in the cable to avoid the inner cable pinching. To avoid chafing on the offside torsion bar I used a plastic cable tie to secure the drive cable to the brake pipe (below right).
Some research showed that there is a standard Ford cables that should work although I haven't physically checked it;
However a search of a few motor factors, eBay or autojumbles may turn one up at a good price, please let me know if you use either of these.
I had to pack the gearbox bush up away from the crossmember, so that I reduced the angle that the front propshaft UJ has to go through. My target was to get the same angle as the original Marina arrangement. The Marina 1800 engine lays back at 5 degrees to the horizontal, I used a vernier spirit level to get it all to the right angle. This also helps the carbs as too steep an angle will affect the floats in the float chambers potentially upsetting the cars performance.