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I got a '87 z31 LSD (w/ some questions)


Phyxius

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Thanks for the lead on the clutches. That's a pretty good deal comparatively, although you can buy a whole set of Eaton carbon fiber clutches for a domestic and they're only like $40. Even so, at $15 a pop you might consider trying to eliminate the washers. If that diff had more clutch disks in it it probably wouldn't have sheared the teeth off.

 

I'm almost sorry I saw that. Makes me want to take mine back apart and add more clutches...

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Thanks for the lead on the clutches. That's a pretty good deal comparatively' date=' although you can buy a whole set of Eaton carbon fiber clutches for a domestic and they're only like $40. Even so, at $15 a pop you might consider trying to eliminate the washers. If that diff had more clutch disks in it it probably wouldn't have sheared the teeth off.

 

I'm almost sorry I saw that. Makes me want to take mine back apart and add more clutches...[/quote']

 

I was thinking the exact same thing. I wonder what the performance difference is between grooved and smooth...

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I would guess that the grooves hold oil so they don't chatter as much. You'd probably have to have the right kind of steel to make your own. I wouldn't be worried at all about running grooved and non-grooved clutches though. You could even sandwich the grooved plates on a non grooved disk and vice versa if you wanted.

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I would guess that the grooves hold oil so they don't chatter as much. You'd probably have to have the right kind of steel to make your own. I wouldn't be worried at all about running grooved and non-grooved clutches though. You could even sandwich the grooved plates on a non grooved disk and vice versa if you wanted.

 

I wonder what the right kind of steel is...

 

I can't seem to find a good way with 1.85mm friction disks (those are the cheaper ones) to eliminate the spacers...

 

I'm getting very confused by all of this. Everyone has reported different clutch pack thicknesses. Yours were 20.1, Nissans were 23.65-75, another was 20.8, and mine is 23.51. I'm not sure what to shoot for. If mine and your clutch packs are the same, I can't think of where 3.4 mm worth of difference would be, unless you only counted 1 spacer...

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I would expect the right kind of steel would be HARD so that the ears didn't tear off.

 

I went through my notes and couldn't find my measurements, then I checked my sent emails, and the one I sent to Gordon Glasgow had them. Here's what I had written down:

 

Spring plates: 4 @ 1.75mm

Spring disks: none

Friction disk: 2 @ 1.75mm

Friction plates: 4 @ 1.65mm

Big end washer: 3.25mm

 

Looks like I only counted the end washer ONCE. I really suck at math. If you EVER see a number in a thread of mine that needed to be calculated you're doing yourself a favor to doublecheck it... it's not the theory, it's the simple calculation that I always F up. :wink: Anyway, count the washer twice and I get 23.6. So we're right in the same ballpark.

 

If you want to start that now, here are some more calculations you can't trust. I do think that 2 spacers = 6.5mm, and 4 friction disks at 1.85 = 7.4mm. So you have a .9mm difference which equals .03543 in. That means your clutch stack is thicker than you want it. Might be possible to make one thinner clutch out of your own material like you suggested. If you did, I'd make the clutch stack 23.6mm again, and shim it up. You might find that with a higher number of clutches you get more breakaway from the same spring pressure and it doesn't require as much shim.

 

If you do add clutches, ideally you'd like these things stacked plate,disk,plate,disk,plate,disk. I can't remember if you would have any issues running a disk on the inside. I don't think there would be any problems. If you could then I'd run a disk in the center, then a plate, then a disk, then a plate then a disk, then your spring plates on the outside. I wouldn't separate the spring plates to put a disk in between because then you'd have each spring working independently on each side and it would be a bear to close the thing.

 

Also in looking over the whole thread again I see that you never got the side gears out. There is LOTS of surface tension from the oil behind the side gear, but tap it with a hammer and you should be able to get the side gears out. You really want to inspect the surface behind to make sure that there is no galling behind the gear.

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Ok...so here is where I am.

 

I've drawn up a friction disk in CAD. I feel that it is very close to the original part, though I can't be sure because both of mine are broken. I compared it to a picture that jmortensen took of his, and it looked very close.

 

I'm still researching materials, but I've narrowed it down to a high carbon 1000 series steel or a 4000 series (most likely 4340). These are all very tough materials and are likely better than what was originally in the differential. Now here's the kicker... I can get stock in 1.6mm or 2.0mm, but nowhere in between. I'd rather not have to mill the thickness down if not absolutely necessary, but the raw stock will probably have some scratches and such on the surface. Also, the 1.6mm stock would allow for 6 total friction disks in the differential if the big spacers are taken out. That is a great improvement over the 1 that came in it.

 

Now, I can have these made for a reasonable price (~$20-30 per disk) considering Nissan doesn't love us anymore. I may even draw up the friction plate as well and offer an entire clutch pack. The questions are what is the demand for it, and would it be worth my time?

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I am about to pull my R180 LSD out of my car and go through the same things you guys are talking about here. I was researching where to get clutches and disks and I found this place, http://performancenissanparts.com/catalog/index.php?cPath=1002_1003_1027_1030&osCsid=dfd9b016c39e46a146beae3ac46a3724 , Performance Nissan Parts, and they list clutch disks and plates for ~$15 each for the R200.

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Did you try other manufacturers that use this diff... Like Subaroooo.... They may have the parts you need....on the cheap too...

 

I don't believe subaru ever made an R200. I searched NASIOC.com thoroughly and couldn't find any reference to a subaru r200.

 

 

I am about to pull my R180 LSD out of my car and go through the same things you guys are talking about here. I was researching where to get clutches and disks and I found this place' date=' http://performancenissanparts.com/c...6beae3ac46a3724 , Performance Nissan Parts, and they list clutch disks and plates for ~$15 each for the R200.

 

If they have them in stock, that's great. I've ran across several people to list them, but can't get them anymore. I'll give them a call and see what I come up with.

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I really don't know dick about machinists and all that, but if you have the right thickness material could it be laser cut instead of machined? Seems like that might lower the cost of producing the clutches.

 

That is exactly what I was looking at doing :)

 

The cost is highly dependant on the number that I make. Heck... If I had enough interest to make 100, it would only cost me about $4 per disk...and I could in turn...sell them for less.

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