Liquimoly diff fluid sucks

[Icecream]

The diff was fine. I'm not incompetent and definitely filled it with the right viscosity. It was not under filled or leaking. I put Liquimoly in and the diff began to fail. Also note that the fluid that came out on my diff service looked good and healthy the first versus grey and sparkly this time.

I'm not a fan of liquimoly but! If your diff failed from it then it stands to reason many more would be failing by now and we would have heard many epic tales on the internet about liquimoly killing diffs. I dont think that is the case though. Your diff could have just failed. Not something you did wrong or because of the oil, it just went bad from use and contaminated the oil.
How many miles on it?

[Silbergrau metallic]

I started hearing a scraping sound coming from the rear of my car and thought is was possibly a worn spring in the E brake. After the adjustment the noise was still there. I spun the wheel and checked for play in the bearings to find they're fine. I even did a 996 brake conversion with a full brake flush. Didn't fix it.

I REALLY didn't want it to be the diff but it is. I drained the fluid with about 8,000 miles on it and it came out grey. The last fluid came out clear and the bottom of the diff had no excessive metal. The car has 77,000 miles and metal doesn't just shred, unless it isn't properly protected. I can understand if my clutches are going, but this junk killed my diff in 8k miles. I should've invested in some different fluid sooner but it is what it is now.

This is a heads up for those using it, you should probably find a different fluid.

I could hear a sound coming from my rear differential everytime I'd make a left turn, so I added the BMW Friction modifier and still heard the sound. Bucked it up and purchased 3 bottles of the outrageously expensive BMW Diff oil and problem solved and now quiet and smooth as Butta.

[Flat-Six]

Ignorance. I thought Liquimoly was good then. I hadn't traveled far enough down the oil rabit hole yet. Why drop $150 when you can spend $40 on something "just as good"? That's a week of groceries.

I've definitely learned since then. I was still at the beginning of my journey as a technician.

yeah, I learned years ago, at the expense of an engine, that some corners are not worth cutting. Good Luck going forward, and hope you get it sorted out.

tim

[JayVee]

Hold on now...

A diff fails and it can only be the diff fluid’s fault? I highly doubt that.

Sounds like there is a bad bearing.


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+3 Liqui Moly makes quality sourced, synthetics. So I suspect abuse or a worn seal/bad bearing. No way this is ONLY the fluid's fault.

[bigjae46]

Just thinking...

A fluid can certainly cause a transmission to fail.

For a manual, FM will destroy brass synchros pretty quickly. The FM will dissolve brass.

For an auto trans, the fluid is placed under pressure and lubricates.

In a diff, it just sits in the bottom of the diff and the ring& pinion gear, LSD and bearings rotate in it. No pressure and no compatibility issue.

If you had bearing grease get in then that would indicate a leak. If the level is too low then you will get a whining noise.


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[enjoy_m3]

Changed fluid....diff fails....blames fluid without actually taking the differential apart for inspection...says they're not incompetent. Something isn't making sense. Might be worth taking it apart before any further opinions are made.

[George Hill]

If it was grey then it could be grease from the CV joint getting in through the input seal?

I don’t see how a diff oil causes a diff to fail other than the LSD unit.

Jae, I think it is impossible for driveshaft CV grease to get into the diff without the gear oil from leaking out. The grease would have to get between the splines of the pinion and pinion flange and I don't see that happening.

I think this is just a situation that OP is trying to find a cause to a problem without any further investigation or consideration. He very well may be right, but it's not like these diffs don't fail on their own so I think it is a bit of a stretch with the info we have presented.

[lemoose]

This is a very unscientific conclusion here. Ive been running LM on my diff for over 60k miles with no issues.