General Approach to transmission adapters

[skid]

Been thinking as no one has really majored on transmission swaps explaining the knock on effect on the input shaft from adding an adapter plate.

Please correct me if I've missed the obvious but if you manufacture an adapter plate for a manual transmission and use the related flywheel, clutch and bell housing associated to the 'box, is the input shaft usually long enough to still operate the clutch?

If an adapter plate is 15mm approx then the spindle is going to be 15mm further away from the spigot bearing.

My situation is that I want to mount the 1UZ to a Posche torque tube. I thought the easiest way was to use uprated Porsche clutch components and porsche Bell, make an adapter plate, and then a flywheel with the 1UZ crank end bolt pattern and ring gear and Porsche clutch cover bolt holes. Therefore the fly would match both manufacturers and the depth of the fly would be the bridging distance created by the manufacturers layout with an addition of an adapter plate. I was wondering whether the additonal length caused by the adapter would mean that the spigot bearing would need to be machined into the fly, rather than the crank as the input shaft wouldn't reach that far any more?

Also if the fly was a bit deeper than expected I was considering getting it made out of aluminium to lighten the weight.

Have I missed the bleedin' obvious somewhere?

Cheers
M

 

[turboandrew]

I am honestly not sure about the porsche torque tube, but you do have a valid concern. I would do everything I could to make sure the input shaft is where it's suppossed to be. If needed, maybe to can mill down the torque tube flange and the V8 rear flange to make room for the adapter thickness.
For 1UZ to v160, there is already a 3/4" space deficit. The 2JZ (what the V160 usually came with) has a rear flange which protrudes 3/4" further than the 1UZ (relative to the crankshaft), so adding a 3/4" adapter actually puts the input shaft exactly where it needs to be.

 

[skid]

Thanks for that.

So as the 1UZ is an an engine mated to auto normally how do you measure the deficit/gain between 2 different set ups when mating them?

So crank end difference to block end, then bell end (snigger) difference to the clutch plate face. This totalled amount then less the adapter depth should therefore equal the fly depth?

M

 

[turboandrew]

Idally one would measure the distance between the rear engine flange and the end of the crankshaft, where the input shaft is to reside, then comapre this to the distance of the 1UZ rear flange and its crankshaft (where the input shaft would go). So, for example, if the 2JZ rear flange ended at exactly the same position as its crankshaft (0.00" measurement), and the 1UZ flange was 3/4" foward of the end of the 1UZ crankshaft, then I know there needs to be 3/4" made up by the adapter plate.

One other factor is that you use a different thickness flywheel. This could affect the position of the clutch fork. Also, if the input shaft is not exactly where you need it, based on my own personal observations, you may be able to have the input shaft further in the 1UZ crankshaft. The hole in which the pilot baering resides is quite deep, and the bearing can be positioned with about 1/2" play further in/out that hole.

Honestly a lot of this is best figured out with both the engine and the tranny in the same place. fit the two together without an adapter plate and just get an idea of how much thickness you can get away with on the adapter plate.