ok, then there would have to be some benefit to the nismo H145, if its not lsd maybe it just doesnt whine like a b@#ch

I don't believe that any diff that is in sound mechanical condition & properly set up will whine like a b@#ch.

If it does, there's something wrong.

Or maybe it just costs a bomb cause it's got a Nismo badge,but perhaps you get a couple of free Nismo stickers as well

lol ill go look and find out about these and see and take some pics and post them later this week

It sounds like a regular Datsun 1000 diff, which were alloy.

What would be the difference between B10 alloy diff and a Nismo/Datsunsport aloy diff?

imho the H145 diff is the low point of the datsun 1000, they get very noisy very soon, and spin open wheel way too easily. they very light so ok for racing if u dont care about the noise. the nismo H145 would have to be a big improvement there or I would prefer spend money upgrading it to something else altogether.

Quote:
I disagree
The alloy H145 diff used in B10 based vehicles was a brilliant stroke of Datsun engineering.

The strength was well matched to the weight of the car & the power of the engine. It provided reliable service far beyond the expected service life of the car & the method of construction, with it's fixed length spacer & shims for pinion bearing pre load, meant that a seal or front flange could be replaced without differential removal & complete tear down as is the case with the 1200 & newer Datsun differentials.
The alloy carrier was more than strong enough to handle the intended loads imposed on it & contributed a net weight saving to the vehicle & remember, low weight is what helped that puny little 988cc engine perform so well at Bathurst in the late 60's.
Low weight is the B10's real strength.

It was discontinued in the 1200 because of cost, although some Aussie 1200 four door wagons seem to have been delivered new with these in order to provide the lower 4.11 to 1 ratio.
The collapsible sleeve method of pinion bearing preload that was used in the 1200 diff was MUCH cheaper to manufacture & the iron carrier was also cheaper to make. The 18.5% increase in capacity of the 1200 engine also had more power to haul the additional weight load. Keep in mind that this increase in engine capacity was all in the stroke [18.6% increase] which delivered more critical torque.

For the intended design purpose, the alloy H145 differential was a beautiful design with much more going for it than later units, in my view.

A noisy diff, any noisy diff, is one that is outside permitted tolerances & needs attention. The cause of any wear should be determined & the cause rectified.
As for open wheel spinning, this would be a characteristic of the open wheel design of the differential & the way that the driver operates the vehicle, but would have nothing to do with the fact that it's an alloy H145

agree with all that, I mean i have heard here of fully worked A15's racing with the H145 with no drama, I just find them getting noisy when u run at 80kmh or more for a while on the freeway.

Just how many of these noisy diffs do you have?

It might be a good idea to check the temperature of the diff after a while on the freeway. If you can't put your hand on it because of heat, then it might be a good idea to drain the oil & see what's in it, then refill with a suitable grade of oil to the correct level.
This might even mean switching to 140 weight diff oil if heat buildup is a problem, but I never ever had a problem with mine & that little sedan got a flogging at more than 80kph on my weekly 120 mile [193k] round trip to Goulburn back in the early 80's.

If diff noise persists, see a diff doctor, .... or replace it with one that is KNOWN to be good.

Speaking of noise, that's why Nissan stopped using the 3.90 ratio. The 3.889 ratio (per the Nissan book) is supposed to have less noise, something about the number of teeth. Now this wasn't about a "noisy" (worn or out of spec diff) but about making the B210 quieter than the B110.