Thread: IIA gearbox/tcase into S3 - Questions

Hey all,

I have a IIA gearbox and transfer case which I would like to rebuild with a view to swap them into my Series 3.

The main reason for this is to avoid having the car off the road while I do the rebuilds.
I would like to have them ready and then just swap in.

Just wondering though;

- Is the SIIA ('67) transfer case the same as the S3 version? (they are both 109's, IIA has rover diff though and S3 Salisbury)

- Can I "synchronise" the SIIA gearbox and retain its (alleged) higher strength?

Are there any other pro's or con's you all see here?

Thanks,
Ash

Gday mate, i have just been there and done that to my s111 1st gear got striped and i had a good s11a box handy i swaped the s111 bell houseing and clutch set up onto the s11a box the only dramer was i had to get a bush made up for the lay shaft as s111 box has little inner diameter shaft than the s11a $80 brass bush easy!! works like a dream, but then a do enjoy driving crash boxes

Originally Posted by Lotz-A-Landies

See above in red

The strongest SIIa boxes are the suffix "D" which solved the layshaft rear circlip issue with a shoulder and had the benefit of the larger bearings. The argument about SIII boxes comes from the early SIII tossing their reverse idler out the side of the case. If you have an SIII box with the lattice reinforcing over the idler this shouldn't be a problem. Theoretically the SIII layshaft being a single cluster sould be stronger than the SIIa shaft/gear arrangement. SIII first and second gears are narrower because they had to shrink to fit the synchro mechanism, SIII boxes are more expensive to repair because of the cost of the cluster.