TVR Vixen - 5 Speed Gearbox
When I bought the car the previous owner had had a local garage fit it with a five speed gearbox. This is relatively straightforward - it needs a gearbox, clutch release arm and bearing from a Sierra 1.6 OHC with a new 23 spline friction plate. The gearbox bolts straight up to the engine. The propshaft needs shortening and an appropriate front yoke to fit the new gearbox. A new gearbox cross member cut in a delta shape from flat steel completes the fitting of the gearbox. Unfortunately although the bearbox was fitted there was still other work to do.
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While the garage who installed the gearbox seemed to have done a reasonable job there were a few other things to adjust. The exhaust fouled the chassis at the back of the engine, the new gearbox cross member and the back of the gearbox as the five speed gearbox is longer. My solution to this was easy. I took the car to JP exhausts (fortunately only about 10 miles away) who supplied (but didn't fit) the exhaust and asked them to make it fit. They modified the manifold, the centre section and added an extra mount at the back of the gearbox. They also dramatically improved the ground clearance.
The Sierra gear lever fitted to the box did not fall easily to hand and needed to be modified. The first idea was to bend it. This was a total failure as the gear lever is made with a rubber joint in it and this absorbed all my bending effort. The next idea was to try a Capri gear lever from a scrap yard as they are straighter - (these are much easier to detach if you remember to take the correct Torx bit with you). This was still not ideally placed
The third strategy was to cut the rubber bush off the Sierra gear lever and remove the other rubber and plastic bits to bend it. This worked but left the lever short and rather stiff to use. This was improved by adjusting the clutch which also improved the feel of the pedal.
Finally I extended the gear lever by brazing the end of the Sierra lever to a bar drilled to fit the stump of the gear lever and drilled and tapped for a clamp bolt. This was topped off by a wooden knob turned in the drill to match the steering wheel.
Of course the easy solution would have been to buy a quick shift lever.
If you are contemplating doing this to a Vixen S2 or a very early S3 then don't forget that you will either need to convert to a cable clutch or use a different bellhousing.
| Is it worth the trouble? If the car had had its original gearbox when I bought it then I wouldn't have changed it. The benefit is mainly that the overdrive fifth gear reduces noise on motorways. The slightly lower first gear also makes it easier to get moving without slipping the clutch. Against that you must set the large gap between 1st and second and a less precise gear change on the five speed gearbox . |
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