Well, I was thinking maybe for the s/c car. There are major traction deficientcys at present. I feel that with the torque I have at my desposal, the 4.1:1 open H145 I have at present is really a waste of time. I would love to get an H165 with 3.9:1 for a ute housing I have so I can phantom grip it, but thus far I have not been able to source one.

I don't know if it would work, but you would need to make the spacers 3mm. The distance of the 2mm spacer ring & the second gasket adds up to 2.5mm, plus the thickness of the original gasket that would no longer be used, comes to 3mm.
At least, half a mill is the measured thickness of the two new [uncomperessed] gaskets here on my desk.


Would you really want to risk it?
Surely someone somewhere can make a copy of a standard diff gasket in 2mm alloy or steel.
I am attempting to source a Pitroad ring, mainly for the purpose of finding the "actual" thickness. I'm sure that 2mm is the go, but i want to make absolutely sure.

Which car is this for?

Okay, don't judge me too harshly by this question. but, would it be possilbe do you think , to make up some chunky washers, 2mm thick. And use those to stand off an H150 head, in a 145 housing? and then run around the periphery of the diff head with a caulking gun, filling up the gap with some high grade sealer? Or does the rear axel assembly rely on having full surface area contact for strength? (I know that the diff housings are pretty flimsy) The reason I ask is I can use a lathe anytime(to make spacer washers), but making a spacer shim requires a bit more presion and care.
Also I know a bloke who has a 3.7:1 diff head.

I also reckon that this thread has some good info worthy of the tech section.

1980 210 trans spec chart
According to my 1980 210 service manual, 3.54 ratio (H150a) was only available with the A15 and 5spd.
The model variations are shown on another page. According to that chart, the non-California, 2-dr, sedan was available with an A15 and 5spd. All other models with A15's had an auto.

B210 sleeper
I have just hit the books & it looks like the195x50x15 tyres that you are using are a nominal 577mm in overall diameter, while my B310 owners manual says the original size was 155-SR-13, which measures a nominal 580mm
Several options present themselves
1. Look for an overdrive five speed box [if you dont already have one.]
2. Find a 3.54 to 1 diff
3. Use larger diameter tyres on the rear.
205x50x15 = 587mm.
215x50x15 = 597mm. Even this can be used on a rim as narrow as 5-1/2 inches.

A combination of these should give you more "gear" than you would ever need.

Quote:Ideal gearing? Thats a hard one. If you are into short trips, like in drag racing, then the lower ratio's like 4.11 to 1 or even lower, will work well. For general road use, particularly in an urban environment, then 3.9 to 1 seems to be a popular shoice.
If you live in a country area like me, where longer distance driving is the norm, then 3.7 to 1 may be a better choice. Lower ratios provide faster acceleration & better hillclimbing, but lower speeds in all gears.
Higher ratio's, like 3.7 to 1 translate to slower acceleration, but better cruising.

Wheel & tyre diameter is also used for gearing changes. The larger diameter tyre increases overall gear ratio & is good for touring/ cruising, while smaller diameter tyres give better acceleration, but lower speeds, so are better for drag racing.

Your best bet is often to just drive it & see how it feels. If you are always looking for another gear, like i was, then you need taller tyres, and/or a higher diff ratio.
If you hardly ever get it into top, & feel a desperate need for more "G's" when you hit the pedal, then smaller diameter tyres and/or lower diff ratio should be on your shopping list.

Sounds to me like you need taller tyres.
There is a 3.54 to 1 ratio in existance, in the H150 diff format, & that seems to be the diff size you are using already, so if you can find one, then [A] Use it & [B] tell us what it comes from, because i am interested in this ratio for my car.
Hope that helps.

P.S. Can you get a speedo from another version of your car with a higher speed indication? Even the humble Datsun 1000 had speedo's with 100mph markings.

R-Fast
The 1200's track is about 60mm wider, but i will stick with what i have for now, unless it proves to be a problem. The smaller, original, rear axle & diff offers a lower unsprung weight, which translates to better ride & handling. I never broke anything in my sedan, with it's original rear end & the 1200's H145 diff of 3.9 to i ratio. The only real reason for the H150 diff change is to get the higher 3.7 to 1 ratio.

Hey Dodgeman,
How much too wide is the ute diff for your 1000 ? Have you considered reducing tube length on a ute diff - there is a resonable amount of spline unengaged so a minor shortening is possible without resplining perhaps? Just a thought.
Cheers

what gearing is ideal? I have an HA37. Higher final drive numbers = lower top speed / more torque?

for me higher top speed would be best, i have the 80mph speedo and freeway driving tends to get it pegged.

Quote:I thank you for the flattery. It won't get you "anything", but it will get you as much info as i can provide.

According to my parts book, ALL series 1 & 2 Bluebirds use the same axle shaft [38162- W1000] This means that the spline in the side gears of both the H165 & the H190 diffs that were fitted to these cars, are the same.
It would appear that this spline was widely used, & may be common to all versions of these two diffs for all i know.

While the H190 diff center will not fit into a rear axle housing that is designed for the smaller H165b diff, the Bluebird axles will none the less fit into the side gears of either of them. I guess that the 1200 ute axle shafts splines will fit either one also

I do not know which, if any, H190 compatible axle housing can be used successfully under a 1200.

This is prety much the same dilema facing 1000 owners. I haven't found any other rear axle assembly that is narrow enough to serve as a replacement, as these seem to be the narowest of the small Datsuns.
If i remember rightly, someone [Dattoman_1000?] said that the '64 Datsun Bluebird [410?] has just the solution, but these are a bit thin on the ground these days, so i have not been able to check.
Plan B is therefore to use a H150 diff center, in place of the H145, which will fit, but needs a spacer to push the whole diff center slightly further foward. I'm working on that one.

ok i guess there is only 1 way to see how the diff centre fits.