SII gearbox options

[Phil-tq]

Thanks for your replies to my earlier post about mating an 803 gearbox to a 1098 engine.

I'll take your advice and go with the 1098 box. However, need your input again please!

I don't particularly want to cut the floor of the SII. The 1098 box will probably fit if I remove the remote and fit it afterwards, leaving off the rear bolts and cutting the casting to provide a channel between the box and the remote for the floor to lie in. I've got a 1098 cowl I can use, but this will result in a water/mud trap above the floor. Not ideal, but workable.

However, someone mentioned removing the 1098 remote and mounting the 803 gear lever onto the top of 1098 selector. I presume this entails making up a blanking plate and drilling it for the lever?

Does anyone make a conversion kit already?

Another option - can the rear castings (which include the lever mounts) of the 803 and 1098 boxes be swapped? By looking at them the mounting bolts appear to be the same.

Lastly, is the 948 box of any use in all this?

[liammonty]

I've just converted my 1954 S11 from tatally standard running gear to 948 engine, gearbox and diff, and have retained the original gear lever. This is done (at least in the case of the 803 and 948 boxes- my guess is it would be possible with a 1098 box too) by removing the rear end of the gearbox casting (which as you say, includes the mounts) and attaching that from the 803 box onto the 948, thus replacing its remote control linkage. The only other change needed (not vital, but desirable) is in order to retain protection against inadvertantly selecting reverse (which is engaed on the series 11 by lifting the gear lever, but on the 948 by pulling against a spring) is to swapthe selector rod with the relevent 'knobble' from the 803 box into the new box, else you'll find youself accidentally attempting to select reverse at 40 mph!! I did all this about 3 weeks ago, and the result has been great. So, no need for any kits or anything, just a bit of perseverance! Good luck!

[Phil-tq]

Thanks for that, I've got a 948 box I can use. Will wait and see if anyone comes back with info on the 1098

[rayofleamington]

Hi again Phil,
I've not actually done this mod myself but have heard about it a few times. One of the guys that did it was Mark (BrixtonMorris) so he may have more info if you can get hold of him.
As far as I know it is the same procedure to do this on a 948 or 1098 box, although I seem to remember Mark having to cut the casting - in a Lathe, although someone else did it the same way with an angle grinder.
Sorry I'm not much help on the technical side, despite suggesting this in the first place! I no longer have an 803 gearbox in my back porch so I can't put one next to a 1098 box for comparison.

[forbesg]

However, someone mentioned removing the 1098 remote and mounting the 803 gear lever onto the top of 1098 selector. I presume this entails making up a blanking plate and drilling it for the lever?

It's a case of removing the extension off the 1098 & 803 boxes, milling out around the output shaft of the 1098 to widen it to the same diameter as the 803. When you pull the two boxes apart you'll see what I mean and then fitting the 803 remote.
I didn't do this to my '54, I just cut out the floor and fitted cover, pedals, speedo drive etc. This was fairly quick to do, but there definitely is less leg room with the 1098 cover.

-Grant