Filings in oil from Cusco LSD

[llloyd]

I have a 1.5way cusco lsd at my buddies shop right now getting a new ring & pinion put in. When they drained the oil from it they called me up saying there was a lot of wear particles in the oil but the oil itself looked brand new, which it is. The car is track only and the LSD has only seen 8 or so track days and has had several oil changes in there, but it's worth noting it's always been obnoxiously loud. Anyways I'm not familiar with clutch type LSD's at all, is it normal for there to be metal filings/particles in the oil when it is drained? I'll guess the LSD has <1000 miles on it could this just be break in? Or is this noisy bitch probably already done.

[totta crolla]

Surely the shop doing the work can tell you what the problem is.
What is the reason for fitting a new ring and pinion ?

[Deuce Cam]

I have the same lsd and it was insanely loud at first, just ridiculous actually. Clunks? More like bangs and clanks. Many folks told me it was toast, and that "I needed to get it looked at." Anyhoo, it calmed down massively after a while, but it's still clunky at slower speeds while making tight turns. Using a heavier weight oil like 140 with some friction modifier helps.

You shouldn't be getting large metal filings or chunks. A lot of particulate matter is normal though, especially on the first few drains. Fine metal goo stuck to the drain plug magnet is normal.

[assassin10000]

Picture helps.

Did you do the break in procedure?

Try motul 90pa, my favorite for my cusco 2way. Best lockup while still being mostly quiet.

Andrew

[Yosuke]

I have a 1.5way cusco lsd at my buddies shop right now getting a new ring & pinion put in. When they drained the oil from it they called me up saying there was a lot of wear particles in the oil but the oil itself looked brand new, which it is. The car is track only and the LSD has only seen 8 or so track days and has had several oil changes in there, but it's worth noting it's always been obnoxiously loud. Anyways I'm not familiar with clutch type LSD's at all, is it normal for there to be metal filings/particles in the oil when it is drained? I'll guess the LSD has <1000 miles on it could this just be break in? Or is this noisy bitch probably already done.

adding to assassin and deuce cam, break in procedure & the right gear oil is imperative to proper limited slip operation.

Cusco LSDs are set at 100% lock from factory and the metal debris should start going away after a few oil changes. With different combination of clutch plate order, the lock up rating can be dropped to 80%, 60%..etc
Yes the LSD will be loud when first engaged at break in. After proper break in procedures and both sides of the clutch plates have been broken in evenly, the sound should subside. So while you have the LSD out you should think about dropping your lock rate (make it slip more) or play around with different grade gear oil. Do not use third party friction modifying additives.

[llloyd]

I've been running the Motul 90PA from day one. Break in was done, and changed the oil out right away after the first autox since it was so loud. I'm going to try the cusco diff oil this time see if it is happier with that and hope the filings are just because it's still a relatively new LSD.

Ring/pinion change is to adjust the gear ratios, the 1st gear is too tall in the new transmission so putting in a 4.778 to bring it back down a bit.

[Deuce Cam]

I also tried 90pa at first and it didn't work well for me. I noticed that the diff got noticeably more clunky after longer drives (20+ minutes roughly). I switched to plain jane valvoline 75w-140 ns with added motorcraft friction modifier and it seemed to help on the longer drives back when the diff was still obnoxious. I'm still using that combo now with no issues; diff. locks up like a best and provides great stability.

It's probably best to go with the heavier weight 80w-140 cusco lsd oil since that's what is recommended (I just couldn't justify the price). Or, maybe try the OS Giken 80w-250.