2manyZ, don't worry about it. I was trying to clarify just to find out for myself. I would love to have a LSD but don't have the money!

GreenZ, yes you should be able to swap a different ratio ring gear into a LSD diff. However, I would recommend the Quaife gear type LSD over the Nissan clutch type LSD. From my experience, although not with Z's, the clutch type is more likely to fail, more tempermental and less smooth. Also, with a Quaife it would probably be easier to select the diff with the ratios you like and then add the LSD. Either way you should have a pro install the parts in the diff, setting the preload and such requires the right tools. Having a pro do it will tend to make them last a lot longer!

All, I have gotten quotes from www.autogator.com, just west of Sacramento, CA, on a R180 4.11 for $175 + shipping. I expect all the ratios will cost about the same. By the way this is a open diff, NOT LSD.

Have fun!

First I wanted to say that I found alot of this information very helpful. Next I wanted to know what the difference was between say an R-180 and an R-200 I know it is heavier but how much and what are the pros and cons of the two i.e. durability and what not. Also I am not familiar with the term Quaife could someone explain that or point out a website to check it out? Another question what all do you need to put an R-200 into a 1973 240Z? One last thing as far as 5-Speeds go is the gearing on them all the same or do different years have differnt gear ratio's in them?

Well, I won't go into the Quaiffe issue. Got to www.zhome.com and look for a technical article there that goes into great detail on the Quaiffe diff. Their web-site I believe is www.quaiffeusa.com

Yes, the R-200 is heavier since it has a larger ring and pinion hence the larger heavier case. Is an R-200 needed in an early Z-car? IMO, no, unless you are planning a V-8 swap in which case it will be a necessity since the R-180 won't hold up to the torque for long.

An R-200 is not hard to put into a 240. You need the 280 moustache bar and lower transverse link. The bolt pattern is a little different on the moustache bar and the transverse link is curved to clear the larger diff. You will also need a front mount for an R-200, plus the flanges will have to be changed to mount up to the 240 halfshafts and driveshaft as I believe the flanges are not compatible.

The early 280 5 speed has slightly different ratios than the later 280zx 5 speeds. Most people will agree that the later ratios are better. These are the non turbo 280zx transmissions not the later T-5 transmissions that came in the turbo's. I have the ratios here somewhere so that you can compare them but can't find the list. I believe the overdrive is higher in the zx trans. and there are slight differences in a couple other gears. I believe the zx trans has a lower 1st gear as well.

Quaiffe is a UK company that builds and sells internationally high quality gearboxes and limit slip, posi, diff (LSD) units. They do not sell complete diffs, just the portion of the gears that replace the pinion gears and make it a limit slip. So one would have to remove the ring gear and pinion gears from the diff, mount the ring gear on the Quaiffe unit and reinstall and reset the preload settings. One little tivia bit is that a stand or non-limit slip diff is refered to as an "open" diff.

As you may already know the advantage of a LSD is keeping the inside wheel from breaking loose, spinning, when exiting a corner under heavy acceleration, like drag racing.

Regarding Datsun/Nissan diff & trans ratios, there is a great site that has lots of the Z ratios and can calculate speed per RPM with different combinations, including different tire sizes. See http://www.geocities.com/z_design_studio/. The only note is that this site lists the '70, '71 series I & II stock4-speed trans as 240. And it also lists the '72 240 through 280 4-speed as a 260 4-speed. Otherwise I would say everything is pretty well marked.

Have fun!

Ok, it sounds like there may be some confusion and misinformation here.

To summarize will someone please tell us in which car(s) an R180 3.9 can be located? As well as where an R180 3.7 can be found?

Ok, here's a list of what came in what......

3.36

R-180: 240-260Z manual trans

R-200: 280zx 6/78-7/79

280zx auto's and 280ZX Turbo's

3.54

R-180: 240-280ZX auto's

Maxima sedan, manual trans

R-200: 280Z manual, 280zx Turbo

3.700

R-180: 810 sedan

R-200: 280ZX manual 6/78-6/79,

300zx non-turbo and Turbo

3.90

R-180: 720 4x4 1/83-6/83

R-200: 280ZX n/turbo 80-83

200SX Turbo 84, 200SX V-6

4.11

R-180: 720 4x4 6/83-12/85

R-200: 200SX Trubo 85-86,

200SX n/t 84-88

4.37

R-180: 720 4x4 6/79-12/82

R-200: n/a

4.62

R-180: 720 4x4 Long bed 6/79-6/80

R-200: n/a

Now all ya got to do is find them in a junkyard.....:cross-eye

2manyZ's wrote:

"Now all ya got to do is find them in a junkyard....."

Yeah, and hope nobody changed the ratio from stock! I hate it when that happens!!! :stupid:

The web site I listed previously doesn't include the truck ratios! Great chart 2manyZ's!!!

And don't forget, the 77-78 280's also used R-180's....

The only rear in that group that might possibly have an LSD would be the 200sx after 1987, but that is up for debate.

5 speed 240z in Australia and a assume UK aswell had 3.9 R180's.FYI. i have one under my house.

Anyone from australia know what sort of diff ratio were behind the oz delievered 240z automatics?

not sure but i expect the same ratio as th US auto's

3.54 I think, well thats what the two diffs from behind autos have been that I have pulled out.