Quote:

The info is from Haynes manual (I thought it too tediuous to list all the exact details but the statement re USA models is correct within 10kg depending on model).

Maybe due to heavier bumpers, emmissions gear, cat converter, air-con, etc - don't know about Aus, but in NZ we didn't get any of that drama. Accept it does seem a lot extra though.

In the never ending search for more mpg's I am searching for a 3.54 final drive for my B210. Most 210's and B210's had 3.70's [like mine] or if equipped with an auto trans, 3.90's. OK, so my factory shop manual says that a the 3.54's were available in the 1980 210 with 1.5 liter engine and a five speed. That certainly narrows the opportunities to find one. So I know where there is an '81 210 with that driveline in an old junkyard up in the woods. Here it is.



This place is up on a mountain and you can only get in there by foot. It isn't fun to carry everything you need for a job like this up that hill. But I am serious about improving mpg's so I rise to the occasion.



Pulling the axles......



I brought a come-a-long and other paraphernalia to get it done.






Doh! It's not a 3.54 but a garden variety 3.70 diff. My book said the 1980 cars had the 3.54, but this is an '81. I don't have a manual for the '81's. I thought they'd be the same? Anyone know what final drive an '81 [US] A15 5-speed car is supposed to have?

Wooof.........can never accuse you of not being motivated!!!

At the very least you're having an adventure that 99% of the world could only dream of...........er or at least a very vivid nightmare.

Tom

In Australia, the five speed & auto versions of the series one & two P910 [Bluebird] came with a 3.9 to1 diff ratio, but the four speed base model had a 3.7 to 1 ratio.

Five speed = overdrive output ratio with lower ratio diff.
Four speed = direct drive output ratio with higher diff ratio.
I have always assumed it was done this way so that the final drive ratio in the highest gear worked out pretty much the same for both.

I would suggest that the same applies to the US model 210 [B310]
There should be a build plate on the firewall with the ratio of the diff that was fitted at the factory.

The last line of vehicle build info is marked 'Trans. Axle.' & will show the trans model as something like F4W60L then followed by something like HB37
The code for the H150 differential is HA & the 'new improved' H150A differential is HB. The number is the ratio 'code' & 37 is for 3.7 to 1.
The 3.54 to 1 ratio that you seek will probably be shown as 35.

I suspect that you will be looking for a US model 210, coded as either HB310 or PB310 with a F4W60L & a HB35.
[H= A14 engine & P= A15 engine in these B310 models]

Thanks very much Dodgeman. What you are suggesting makes perfect sense, and now I can use the code on the firewall tag to know what's in the car before I remove the diff. But I am not aware that Datsun ever mated a four speed with the A15 in the US. I'm pretty sure only the A14's had the four speeds. The '80 factory manual clearly states that A15 powered five speed cars were the only ones that used a 3.54 diff. What I am hoping to find out is if someone with an '81 manual could go to the PD [propeller shaft and drive line] section and see what the specs are for 1981. Perhaps the 3.54 ratio was only used for one year in the USA?

Mike

Understood.

I have the 1981 manual, but it is Australian specific & all of the Aussie spec passenger models that were sold here [Four Door Sedan & Coupe] were A12 powered with F4W56A trans & [nominal] 3.9 to 1 diff ratio. [HA38 for 3.888888 to 1,]

The vast majority of the Sportswagons [which are regarded as a commercial vehicle] came with an A14, plus F4W60L & HA38. These were model coded as WHB310's

The last of them here came with the A15 & 60 series but with the HB37 coded differential. These were model code WPB310 vehicles.
In short, we never got the 3.54 to 1 diff.

Hav you decided what boddy your going to use for the eventual all out attempt?

Quote:We never got the B10's here in the USA so that's out. A B110 would be great but I don't have one. I will simply use what I have. Besides, I have no challengers at this point, so I don't need to use the best possible chassis yet. Unfortunately, we're heading into winter so the licence plates will be coming off of the B210 for the next 5 months. Developement will continue next spring.

If I can work my way up to 65 mpg next spring and then later someone else gets 67 mpg in a featherweight B110, then I might need to to go vintage Datsun shopping.

Might be worth a try to call these guys

Check www.car-part.com under carrier and diff of course. Not to be confused with carparts.com two totally different ends of the spectrum here.

Will do.

Thank You!

It's easier to get the credit card out than to remove one yourself.