Better Gearing

[jmortensen]

Someone suggested swapping ring and pinions around to create the ratio of your choice. I checked with my buddy the Z Doc, and he said it's very difficult to get the preload and tooth geometry setup properly (he tried it). Oh well.

HOWEVER: Since the 3.70 and 3.90 apparently use the same 10 tooth pinion, I wonder if a 3.90 ring could be swapped onto a factory limited-slip assembly? This would make a "factory" 3.90 limited slip!

BAD IDEA!!! REALLY REALLY BAD IDEA!!! It's not just the tooth count that matters. The pitch of the teeth on the ring gear of a 3.90 are way different than a 3.70. In other words, the number of teeth is the same, but their angle and length is because they have to mesh with a different number of teeth on the ring gear.

I even think it's a bad idea to swap a ring gear from one 3.70 to another. When a ring and gear set is made it goes through several polishing procedures, the last one on most domestic cars is done with the ring and pinion running together, so when it is done they are effectively a "matched set". While I'm not sure that Nissan does this, it really isn't hard to find the gear ratio you want, and swapping the LSD from one ring gear to another just involves unbolting it from one and bolting it onto the other (using ring gear bolt spacers if you want).

Here is the right way to install an LSD in your open R200. It's not a mystery:

http://forums.hybridz.org/showthread.php?t=119990

Edited December 8, 2008 by jmortensen

[WW2Winger]

John, just read your reply to my question. Why would anyone think that your comment was assholish??? If you hear of a great deal, let me know. The one in your shop would probably be just the ticket!

[soundmasterg]

More clutches, stock Nissan out of the 300ZXT has a weak clutch pack. The Nismo unit has more clutches, the KAAZ has about 50% more than the Nismo. Also you can get the KAAZ unit in a 1.5 way or a 2 way, Nissan's are all 2 way. Which one is better is up for debate, but most would probably say that 1.5 way is easier to drive for road racing or autoxing.

So if I've got a Nismo unit with 4 extra clutches from Gary Savage to add to my Nismo instead of the spacers, then I'm basically where the KAAZ unit is with the exception of being the 2 way instead of the 1.5 way, right?

Greg

[jmortensen]

I can't recall off the top of my head, but I want to say the KAAZ has 16 clutches in it or something like that. It's a lot more than what you or I have got in our Nissan LSDs. What you have there is fine, and by installing the extra clutches and getting rid of the stupid spacers that Nissan used it should handle a lot of power than the original setup did.

[soundmasterg]

Thanks Jon.

I'm planning on somewhere between 300 hp and 400hp, so as long as it can handle that without complaint with the 6 clutches that it will have, then I'm fine with that. I've still got the 4 speed and the original R180 in there right now though. Been reading up on the MM-CV stuff before I swap in the R200 CLSD, because I only want to do it once.

Greg

[jmortensen]

Been reading up on the MM-CV stuff before I swap in the R200 CLSD, because I only want to do it once.

Have you read any of the stuff about the left side shaft bottoming? That's a problem that seems to be popping up more and more on Hybrid Z. I lengthened my rear control arms, you can also grind a bit off the end of the shaft or have a shorter CV shaft custom made. I think Ross was talking about doing that a while back if there was enough interest...

[240ZX]

Don't forget about PRECISION GEAR as a source for R200 clutch type LSD carriers. Very reasonable price as well. Check out thier website.

Tom

[jmortensen]

Tom, if you recall "Mike" over at Hybrid Z had tried and failed to get a group buy going on these, but supposedly they were NLA. I had felt that Mike had handled that situation particularly badly and had wondered if they really were NLA or if the guy just told him that to get rid of him. You got me curious again so I called Precision. They apparently sold out to another company called Amix Ada (I think that's what she said). They didn't have the part in stock, but suggested I call Jeepers Creepers. I told her I didn't think Jeepers Creepers was going to have Nissan parts, she said to call them so I was polite and pretended to take the number down. Then I figured I'd try Reider Racing... guess what? I got Amix Ada again. They do not sell to the public, just to vendors. Apparently the vendors are places like Jeepers Creepers. The second lady I spoke to seemed to know what was going on and she said the part number LOM59-12 was not in stock, and that the ordering dept was gone for the day, so she couldn't give me an estimate of when or if they would be available.

[geezer]

Does anyone know the significance of the part number LOM59-12. My Nismo LSD is cast with LOM59 and the adjacent stamp pad is blank. I did some searching and found that BJ Hines has one that was stamped 25. I have not had mine apart to do a clutch count yet.

[jmortensen]

Does anyone know the significance of the part number LOM59-12. My Nismo LSD is cast with LOM59 and the adjacent stamp pad is blank. I did some searching and found that BJ Hines has one that was stamped 25. I have not had mine apart to do a clutch count yet.

I had ASSumed that the 12 was the diameter of the ring gear bolt holes. Guess I was wrong on that one...

[soundmasterg]

Have you read any of the stuff about the left side shaft bottoming? That's a problem that seems to be popping up more and more on Hybrid Z. I lengthened my rear control arms, you can also grind a bit off the end of the shaft or have a shorter CV shaft custom made. I think Ross was talking about doing that a while back if there was enough interest...

Yeah, I've read all of that stuff, and it is worrying, so I'm kind of waiting for a rock solid solution to sort itself out on this before I swap mine in. So far I've got the 3.7 CLSD and the clutch packs, and thats it.....so I still need more parts anyway before I could swap it in. I've got other things to do to it in the meantime. (T5 swap, door seals, find and eliminate exhaust fume leakage problem, get dash lights to stay on and not go off when I hit bumps so I can put center console back in, etc)

Greg