So no comments on the SII gearbox swap then?

Post by **PhilI** » Sat Apr 19, 2003 11:14 am

Thought this would be the place to ask. Can't believe nobody has tried it.

Post by **Cam** » Sat Apr 19, 2003 11:39 am

Phill,

Why is is not a straight swap??

Surely the bodies / pedal mountings are the same regardless of year?

I have not done this myself, but I have a '69 model with a Sierra gearbox and a '52 with the original gearbox.

The gearbox covers look like they have the same mountings but I have not taken any measurements.

What exactly is the problem?

Post by **PhilI** » Sat Apr 19, 2003 12:28 pm

The first obvious difference is that the covers are different in length. The 1098 box has the gear change further into the car. Will it fit without having to cut the floor pan?

Post by **Robins** » Sat Apr 19, 2003 2:19 pm

Phill
I think all you will need is a shoter propshaft from a later model, a new gearbox cover floor panel from a later model and yes you may need to cut the floor a bit. Everything else should line up but don't hold me to that. Your rear axle will be the wrong ratio aswell I think.
Basically I bought a 1972 pickup chassis runing a 950cc engine on a 803 box and a block of wood between the prop and the rear axle to pack it out (shorter prop from the later model). It also had the 803 floor cover panel for the gearbox wich was smaller than a later ones. Apart from that it was all the same connection wise such as clutch linkage etc. Having never paid much attention to 803 Moggies I can't say for sure
The guy used to drive this chassis round his housing estate. There was a peice of ply screwed to the chassis were the floor used to be, and a seat bolted to that. The steering wheel was attached to what was left of the bulkhead and everything else was gone. But thats another story way off subject. I'll have to put a pic of that on my website.
Hope this helps.
Cheers, Daniel

Post by **rayofleamington** » Sat Apr 19, 2003 3:05 pm

Hey Daniel - would love to see a pic! As for packing the propshaft joint with a wooden block - Crikey!!!!

Post by **PhilI** » Sat Apr 19, 2003 6:08 pm

Spent this afternoon taking out the 803 box and offered up the 1098 with box attached.
It certainly won't fit without cutting the floor. The 1098 box cover panel is a fair bit longer than the 803 one and you can see why.

The earlier pedals are also spaced differently with the clutch and brake both within the chassis leg. The clutch pedal was then moved to leave just the brake pedal there.

I already have a set of 1098 pedals so will use them (in case there are slight differences). Otherwise, I would have to cut another notch in the 1098 cover for the "803" clutch pedal to poke through.

I like to keep things fairly original and cutting the floor is not what I really want to do, but is, arguably, acceptable if the car becomes more driveable. I intend to replace the back axle as well and use the 1098 prop shaft. The 803 one is well and truly stuck on the back of the gearbox anyway. Comparing them, it seems identical to the 1098.

Post by **Rswiper** » Mon Sep 29, 2003 8:25 pm

I see this discussion is fairly old, but will thow in my two-penneth anyway.
The good new is i converted my '56 SII to run a 1098 box a while back, the bad news is i am far from being any sort of expert and as i say it was a while back - my memory is pretty poor for details.
As far as i remember...
Yes you have to cut the floor pan and fit a 1098 gearbox cowling.
I had no trouble with the prop, but i was also fitting a marina 1275 engine to the car at the same time, (here comes my poor memory so dont take this as gospel) i think the 1275 engine needed modded mounts which may push the drivetrain back a bit down the car?, this may be why my 803cc prop was fine.
Yes the diff is the wrong ratio. i have since fitted a better one
I had no trouble with the pedal assy or box mountings, although i assume my pedal assy is fairly late on beng a '56 SII.
Not sure if any of this helps and you have probably done the work since the question was posted.

Post by **Scott** » Tue Sep 30, 2003 2:58 am

You can swap the extension housing from an 803cc gearbox onto a 948cc gearbox. The only difference being that you won't need to lift the gear lever to select reverse. If you fit the 803 reverse gear selector rod to the 948 box, then you will have the original reverse gear operation (lifting gear lever).
If this can be done to the 948 gearbox, it should be possible to do the same to the 1098cc gearbox. I haven't tried this on later cars, only 948 gearboxes.
This mod keeps the floor original & looks original inside the car while having better ratios.
Prop shafts are identical lengths on all OHV minors.
Again, probably late but it might be useful to someone else.

Post by **turbominor** » Wed Oct 01, 2003 11:09 am

I had to cut the floor back to get the box in, easiest to get a 1098 gearbox cover and trim floor to match it