This is yet another BMW Limited Slip Differential Failure by OS Giken, and OSG won't stand behind their product as they advertise! In fact, OS Giken failures are sprouting about all over the web. The failures are not only with the BMW based products.
My OS Giken BM235-HA Superlock LSD failed. The unit had less than 1,000 miles on it in total. It was always run with the OS Giken OS-250R OS011-KA1 Gear Fluid. My car is daily driven. It sees 95% commute duty, and 5% track use. It was occasionally "hooned", but thats besides the point.
The failure started on a Monday. The differential was making a slight clunking/popping sound (almost identical to clutch binding) on my way to work. By the time I made it to the office, the noise had increased significantly. Not only was it audibly louder, but the drive-train shock it produced was much more violent.
The following day (Tuesday), I noticed that the differential was acting as if it were welded or a spool was in the carrier in lieu of a LSD. The wheels were moving at the same speed. This created lots of wheel hop and parking lot chirping. Upon leaving for lunch, I pulled out of the office parking lot and began accelerating at a normal rate. The car suddenly stopped moving (though the rpm's continued to rise) and then suddenly I felt/heard a terrible explosion.
After having the car towed to a shop, removing the differential, and removing the differential case cover; We were greeted with this:
and after draining all of the fluid.....
OS Giken USA Headquarters in Torrance, CA was contacted immediately. Emails were exchanged. Long story short, after speaking with Sean, Jonathan, and Mike; I was told that OS Giken was aware that there was an engineering deficiency with this particular unit and that it has been removed from the market. There was no indication as to when a revised unit would be released (if there will even be one). Also, they would not answer my question as to what they've done in effort to contact those who have a known defective unit.
OS Giken stated that they couldn't replace the unit as they are known to be defective and would not process a refund. Instead, they offered 30% off on any future OSG products.
Anyhow, I just wanted to share this with anyone who was considering purchasing an OSG LSD. OSG claims to be the most reliable LSD on the market.... but this is obviously not the case. Spare yourself the headache and don't end up with a very costly paperweight. Take your business elsewhere, like Dan with Diffsonline! That's where my next diff is coming from.
Update: More photos of OS Giken failure from Minnoe07's thread at this post : http://www.zhpmafia.com/forums/showt...112#post390112
tags: os giken failure, lsd, e46, zhp, bm235-ha, osg
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Originally Posted by HokieZHP
