w57 box

[millsi]

takai, yeah thats what i was thinking.

[Cuzzo]

How can it be stronger? Isnt it just like a spacer?

[Shifty]

As I understand it, the centre plate supports a bearing... and from there logic suggests that taking any weakness or flex out of the bearing support keeps everything true and therefore stronger/longer lasting.

But really.. who bloody knows. I've used heaps of w55-w58 boxes and never really known much difference except the 5th gear ratio.and the steel sandwich plate randomly being included on some.

[takai]

I believe it is that the W58 is believed to be stronger than the W57 and as such a steel plate is more desirable. Same probably goes for the simple fact that one is steel and one is alloy.

Remember, with a lot of the W boxes they were used by people who didnt quite know what they were, but knew they were strong enough to sit behind their V8 (with a dodgy bellhousing). Hence these same individuals are likely to have thought that just because one had a steel plate and one had an alloy plate means that the alloy plate is always weaker. Personally i have heard this many times from these types and would concur that they whole heartedly believe it.

[Norbie]

The gearset is mostly supported by the sandwich plate. It stands to reason that it will cop a lot of the stress when the gearbox torques up, and if it flexes even a tiny amount the gears will get out of alignment and munch themselves.

Anecdotal evidence: of the 4 W5x gearboxes I've destroyed, the two alloy-plate versions had a much shorter lifespan than the steel-plate versions.