Nismo LSD lockup

[HKSZ]

Just replaced the r180 3.9 open with my 4.6 lsd r190 tonight and found its turned into a locker!! Its been sitting on the garage floor the last 10 months but was working perfectly when I pulled it from my 510, now its jumping around the corners just like a locker.

Should I keep driving it till something breaks free :paranoid: I always thought when a lsd stuffs up it turns into a single spinner, or do I have topull it out and reinspect.

[John Coffey]

The Nismo clutch pack LSD can be setup with varying levels of preload. Typically from Nismo they come with a 45 ft. lb. preload but lots of racers increase that number to around 75 ft. lb. My guess is that yours has been adjusted to the higer number or has a problem internally.

But, just to be sure, did you actually open up the diff and check to be sure its a LSD and not just an open diff welded up?

EDIT: Oops, sorry, if you've had the diff for a while and its suddenly acting this way, it needs to be taken apart and rebuilt.

[jmortensen]

Just sounds like clutch chatter to me. It's loud and obnoxious, but nothing to be afraid of really. If you don't hear gears cruching and if the diff worked fine before then I'd be 100% that it is clutch chatter.

Did you change the oil and forget the additive? The Nissan LSD needs that additive and if you don't have any in there it will chatter like crazy. Even if it has additive in it, I'd put some more in and then find a parking lot and do some figure 8's for a couple minutes and see if it goes away. At least 1/2 of the clutches have been out of the oil for the last 10 months. doing the figure 8's will spread it around quickly.

[Murph]

Did you change the oil and forget the additive? The Nissan LSD needs that additive and if you don't have any in there it will chatter like crazy. Even if it has additive in it, I'd put some more in and then find a parking lot and do some figure 8's for a couple minutes and see if it goes away. At least 1/2 of the clutches have been out of the oil for the last 10 months. doing the figure 8's will spread it around quickly.

Agreed. While I can't speak for the Nismo LSD directly, we've been playing with a cusco 2-way here. The best oil/aditive combo we've found so far is Penrite's heaviest LSD oil (HPR160 or something like that) and the Nissan LSD fix oil. Turns it from a nasty chattering, banging, skipping, clunking thing into something that's quite smooth and driveable. In normal driving you wouldn't even know it had a mechanical diff.....but feed some power in and it'll lock up nicely.

[HKSZ]

Thanks

My mechanic refilled the diff with the Castrol lsx85/140 I always use, but the first thing he asked me when I picked the car up was is this a locker diff, because he couldn't get it to slip while on the hoist.

I assured him that the nissan lsd had good clamp up. It wasn't until I had it home off the trailer and drove it I knew what he meant.

Turns over freely and sounds quiet, just hops and pushes in the corners

[jmortensen]

In the US the commonly available additives are the Ford Friction Modifier, GM additive, and the Chrysler additive, and they all do the same thing. There is a rumor that got started somewhere that the Ford stuff will make an LSD more aggressive. Not true. They are all there to prevent the clutch chatter. Add some friction modifier and you should be good to go.

[Ron Carter]

I think it might be wise to inspect what you have. I know that some race teams back in the 70's running R190's did put locking gear sets in the R190's instead of the LSD.

Take a look at what you have and treat it correctly as parts for your 190 are now very hard to find.

[jmortensen]

If he ran it before he would probably know if it was a locker, don't you think Ron? My friend had an R190 with a Detroit Locker in his 510. It was a whole different experience than an LSD. Really brutal when it ratcheted. I had never experienced a locker before I was in his car, and I literally thought the diff was going to be laying in the middle of the road when it started ratcheting. It was positively violent.

I believe the Detroit Lockers were made for the H190, not the R190. The fact that they are the same leads me to believe that the H190 LSD would work as well. That kind of corresponds to John Coffey's recent finding that www.differentials.com and www.reiderracing.com have Power Brute (re-badged Nissan) LSDs currently availabe for the R190.

So it would seem that the tough part would be finding a ring and pinion should one be needed down the line, and that part I do not think corresponds to the H190.

[Murph]

Sorry to hijack the thread, but this is sort of appropriate while we're talking about nissan diffs...

Does anyone here know just how strong the H190 is? You see, my 260C (see avatar) runs an H190 and I'd like to get an idea if it'll hold up to a more powerful engine?

[HKSZ]

Its definately a clutch pack, I've had the cover off it once before just for curiousity. All the crown wheel bolts etc were drilled and nicely lock wired.

And I wouldn't think fitting the same side shafts I had on the r180 to the r190 could make any difference?

[jmortensen]

As I recall from my friend's diff (which I was looking at 10 years ago so memory is a bit fuzzy) the side shafts were the same. If they were different I'd imagine you would have noticed that the splines were different when you installed it, and it would have made a hellacious noise and stripped out the side gears when you first started to put power to the diff had they been wrong.

It sounds like you're still searching for the cause of your chatter. I'd be willing to bet that $5 USD worth of additive will solve your chatter problem. I tried to look up that lube you're using. I couldn't find anything useful on the Castrol site, but Several other forums on the web had posts about needing additive with that particular lube, the last indicates that the manufacturer suggested a particular type of additive that he couldn't find. I think this suggests that Castrol thinks it needs the additives, but again all the additives are basically the same, so just get whichever one they stock at the auto parts store.

Even if you use an "LSD" oil, if you have chatter the solution is to add MORE friction modifier until it goes away. When I used to sell diff parts we sold the Eaton posis with the upgraded springs and 22 plate steel clutch packs, and Auburn Gear Pro Posis. These particular LSDs are the most aggressive I've come across and had several hundred lbs of breakaway force, and sometimes the customers needed 3 bottles of the additive to get the thing to stop chattering. It's one of those things where you just keep adding it until you don't need anymore.

Here are some of the threads I found online:

http://www.ls1gto.com/forums/archive/index.php/f-28/t-35766

http://www.calaisturbo.com.au/showthread.php?t=60039

http://www.fordforums.com/archive/index.php/t-96058.html

http://www.4wdaustralia.com.au/Forum/Archive/2005_3/23987.asp

[zguitar71]

I have R190 in my car the side shafts are the same. I have no idea what the break away is on mine but my crappy street tires do not give enough traction to unlock it all the time. When the race tires are cold it does not unlock either, when they are warm it works like a dream though. I have 2 tubes of the GM modifier in it and have no problems with wierd noises or chatter.