Isuzu G-series Twin Cam

Hey guys,

Im having trouble getting my hands on a gearbox to suit my G180W which will be going into my Gemini. Ive been trying to find a box from a deisel KB but have been unable to do so. Does anyone have a either a twincam box or the Rodeo box? Let me know what you have and how much you are chasing as we can talk further. Im willing to pay freight as well if I have to.

Cheers,

Andy

I have a ZZR or Piazza DOHC box but IMO the early Gemini boxes with .782 5th (instead of .855) are better.

Hence I swap the DOHC (LHS starter) bell housings with the Gemini RHS starter bells.
But there are two common types - the earlier bell with a smaller roundish alloy from bearing cover (that uses a roller bearing for the layshaft) and the later & larger cast type that uses the stronger ball-bearing for the layshaft. (The shafts take either bearing - only the bell & front cover vary.)

Be wary of differing throw-out (clutch-thrust) bearing blocks - their ID and length can vary as can the length of the pivot mushroom bolt. (Mushrooms/pivots can be either side for cable pull or mechanical & hydraulic push pivots.)
And yes, the front shaft can be 16mm or 17mm OD (ie; the 6203 flywheel bearing comes in 16mm & 17mm ID versions; and a 5/8" ID version!)


The last non-twincam LHS starter bell I got was of some early Rodeo - it's bell "dome" was a bit smaller than DOHCs (smaller clutch & flywheel), but it has the same bolt pattern.


The above is FYI in case you have a LHS bell housing that can be separated - ie, NEVER throw them out!

Belletts have LHS starters as do Aussie Florians - but they are a one-piece bell&box (not separable) and only 4 speed (which IMO is far from suitable for a DOHC!!!)

Cheers for the info mate, very useful. Ive found something thatll work for me Cheers

BTW - the things that can vary:
- front shaft diameter (16mm or 17mm ID flywheel/crank bearing)
- front shaft splines (10 x 1" or ~24 x 1")
- output shaft splines AND diameter (I think coarse are all the same, but big & small diameter fine spline variations)

The the front cover (small alloy or large steel)
The cover diameter (for the sliding thrust (bearing) block).
The thrust block length & ID.
The clutch throwout type pull cable else push mechanical or hydraulic forks/levers.
The clutch throwout lever's mushroom pivot (length & either position; can usually tap 2nd position if leaf blank; threads should be the same).


Always get the gearstick with the box (they do vary...).

Some DOHC boxes have an L-adapter for the speedo cable outlet (can be attached to any box to point the speedo cable forwards and not foul cross-members etc.

What did I forget? (Ratios excluded.)

I hope not much else Cheers for the info, much appreciated.