Anything and everything Vitesse.

Clutch, gearbox, overdrive, propeller shaft.

I have purchased a restored Mk2 rolling chassis with a correct rebuilt vitesse engine mated to a rebuilt Dolomite 1850 (WH prefix) single rail gearbox and J type O/D. It is connected to a prop and Diff, etc, but I am not familiar with this modification and wanted to know if this is a common worth while conversion and what effect will it have on the cars performance? From what I can see, placing a bulkhead over it did not show any indication of fouling between the footwells, but I have noticed a 3 - 4mm spacer placed between the D type overdrive mounting plate and the overdrive mounting rubber to give clearance for the J type sump/filter cover. Without bolting a rear tub on, does anyone know if the increased angle of the prop will foul the rear transmission tunnel? Also the gear selector seems to be about 25mm too far back, can this be overcome at all, as it will effect the gearbox cover and any carpet set I may buy? Any assistance on any aspect of my problem would be most helpful.

This is a common modification. Gearbox is same ratios, just stronger. J-type is better as well.

I don't see any reason for problems.

Only slight issue is that the box / OD will be canted over a few degrees.

And as you say, the gear stick is in the wrong place slightly.

get hold of a non-OD gearstick and rebend if required. Vitesses lokk better with a column switch anyway.

Cheers

Colin

The gearbox is not canted over, because the GT6/Vitesse bellhousing is used. The prop shaft is 1" shorter than std Vitesse OD, because the adaptor plate between gearbox and OD is 1" longer.

I have not had a problem with where the gear stick comes out, but it was very long and I had to saw it down.

On the GT6 there are problems with the angle drive fouling the chassis, which can be overcome by shortening the angle drive and speedo take-off in the box.

There is a problem with the selector rod. It comes out the front of the box into a blind hole in the Dolly bellhousing. The GT6/Vitesse bellhousing needs to have a hole drilled in it for the selector rod. The selector rod has a roll pin in it just in front of the gearbox case, which touches the gear box case in 1st and 3rd gears. This stops you moving the stick too far and wearing out the selector forks. The hole in the dolly bellhousing stops you wearing out the selector forks in 2nd and 4th (either the shaft bottoms in the hole or the roll pin touches something - I can't remember).

But with the GT6/Vitesse bellhousing there is nothing to stop you moving the gear stick too far in 2nd and 4th, and you will gradually wear out the selector forks. Look for brass coloured stuff in the oil. So you have to drill a hole and insert a roll pin in the selector shaft just behing where it comes out the back of the gearbox, so it touches the gearbox case in 2nd and 4th. Just like the one in front of the gearbox, only at the back.

Hope this makes sense
Van

Thanks to both Colin and Van for your response. I do intend to swap the gear selector for a standard Vitesse item and use the column switch and shall now contiue with this conversion. A mate did tell me it was a simple wire in job on the J type, unlike the D type. I am glad that the ratio's are similar and it looks like the standard Vitesse bell housing has been used as the box is not canted over. I will look at the roll pin modification to see if it has already been thought about or not. Van, do you have the spacer on your car or not jacing up the overdrive? The speedo cable supplied must be the Dolly item, as it will not mate up to the car. Does this mean a special will need to be fabricated, or will a Vitesse O/D one be OK?

Thanks

Hi David

I have used the standard rear OD mount, which I have moved 1" further back. I have opened out the two holes where the OD screws on by filing them downwards, so the rear of the box is not too high. The main reason for doing this is because the OD mount sits on a plate which sits in a dip in the chassis rails. Moving it back makes the plate sit slightly higher and this was the way I got it back down. This was 11 years ago, when my metalworking skills were pretty limited, if I was doing it now I would make a new plate and use a standard mount. I'm not sure if the problem with the height of the chassis rails occurs on the Vitesse. I don't think the current pattern OD mounts can be modified the way I have, only the original ones can, they have a reinforcing washer around the holes I have filed.

For the speedo cable, you need the right angle drive if you don't already have it. On the GT6 it fouls the chassis. Some people file away a large chunk of chassis, but it is possible to shorten the screw-on ring on the angle drive and the take off on the gearbox. There will now be no room for the U-shaped clamp that holds the speedo take off in place, so put this the other side of the screw-on ring on the angle drive. Use a longer bolt to secure it.

It's actually possible to do without the angle drive, use a long speedo inner, a short speedo outer and run the speedo inner through a right angle hose full of grease up to the speedo take off, it works but it doesn't last long (500-1000 miles before cable breaks) and is OK as a temporary measure.

Vitesse OD cable could probably be used but LHD ones (and GT6 ones) are longer and can be easier.

I don't think you can change the gear shift mechanism without taking the box apart, since some of the bits are inside the box rather than attached to the top cover. The single rail change is much nicer.

No photos I'm afraid but I might be able to draw some pictures at the weekend if you want anything specific.

Good luck
Van

Thanks Van,

I shall investigate further next weekend. In the coming weeks I should be able to pull both rolling chassis' along side each other and take some more accurate measurements and report back.

Regards

Dave

Section : Gearbox

Dolly 1850 gearbox and O/D conversion

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Dolly 1850 gearbox and O/D conversion

Dolly 1850 gearbox and O/D conversion

Dolly 1850 gearbox and O/D conversion

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Dolly 1850 gearbox and O/D conversion