run it till it breaks . have some fun. see how strong your box is before you change it. you might get as surprise.

Thanks for all your thoughts on this topic fellas. Looks like the my 60 series box will be coming out and the toyota box going in. If anyone is interested in buying the 60L box, let me know. After I put in the H190 diff my ute should be pretty much bullet proof thanks to the knowledge I've learnt from this website. Thanks to all you guys. Will post some pictures of my ute as soon as it's complete.
Cheers,

Quote:That is a 60-series gearbox! The question is, is it a 60L or 60A? You can tell: The 60L has reverse above first. The 60A has reverse below fifth.

straight cut gears make alot of noise and wer out quicker

from this informative discussion it seems that straight cut gears r all winning then why not most OEM GB comes with them?
there must b a catch.

a bit off topic, but can anyone tell me what gearbox i have i replaced the clutch yesterday and it has castings 60, and #2 on the r/h side.
thanks.

The Dellow kit is not cheap, as it is more than an adapter plate. It actually incorporates the front part of the gearbox. The upside is that the gearboxes are cheap. They are cheap because they are good.

Huh? Good boxes dont break much in normal service, & they have a long service life, & demand at the wreckers is low, so they are priced to sell.
Those who remember the rubbish 4 speeds first used behind Holden 6's will also remember that wreckers wanted a lot for them. They broke a lot, & demand was high.

Much as i hate to say it, the Toyota boxes are a bloody good trans & are a good choice behind a hot A series.

I learned something too. I always assumed that the straight cut boxes weren't as strong, as there was less contact patch between two straight teeth than between two angle cut teeth.
The transmission losses in a straight cut box are significantly less however....

For a replacement box for an A series, it'd be hard to beat the Dellow kit to fit a (i'll say it) Toyota box...

Hay feral,
Thanks for the info on the relationship between the two shafts, their centres, and the series numbering. I never put 2 and 2 together like that but it makes perfect sense. This has to be one of the best websites in the world, knowledge base is huge.
Good stuff.

Its not hp that kills boxes but torque.

Datsun boxes are numbered by the distance between the centres of the countershaft and the main shaft. 56 series 56 mm, 60 series 60 mm, 63 series 63mm, 71 series 71 mm.

The larger the distance between shafts the larger the shaft diameters and gear sizes that can be used. With helical spiral gears, rotation of the gears under load tends to make the gears try and spread away from the other gear. The shaft must be strong enough to with stand this load without distortion.

A smaller shaft will distort more for a given load than a larger shaft.

My tip is that the A15 will produce about 150 - 160 ft/lb torque and about 230-240 hp @ 14 psi boost.

As a guide the maximum continuous torque limits of the various boxes can be determined by the ratings of the bearings or the torque the smallest diameter of countershaft or mainshaft will take without approaching plastic limits

Approximate guides are 50 % up on the stock engine torque : -

56A 4 speeds 105 ft/lbs
56A option boxes 120 ft/lb
60 series boxes 135 ft/lb
63 series boxes 175 ft/lb
71B series boxes 240 ft/lb
71C series boxes 300 ft/lb