Pic of BMW "Lifetime" Diff fluid @33k vs. Virgin Redline 75w90

[Jim 5]

For anyone who's interested..

On the left is the stuff I drained from my diff at 33k miles in my BMW 330ci compared to the virgin Redline 75w90 in a clear coke bottle (for comparison). This isn't scientific, but it makes you doubt the whole idea of "Lifetime" fluid service. I'm sure it doesn't start out this black. Would it be good for another 200k miles? My diff isn't going to find out. I'll stick with 30k miles intervals.

[ October 11, 2005, 09:34 PM: Message edited by: Jim 5 ]

 

[o2man98]

UOA ??????

 

[Steve S]

Usually the most wear in the differential occurs within the first couple thousand miles along with all the sand from the casting and new product dirt .So you were running around with real dirty oil in your differential

 

[Steve S]

quote:

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Originally posted by Steve S:
Usually the most wear in the differential occurs within the first couple thousand miles along with all the sand from the casting and new product dirt .So you were running around with real dirty oil in your differential

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For 31,000 miles it probably won't matter though.

 

[mechtech]

Could have moly or some other additive in it.

 

[Pablo]

Color doesn't really matter. Is it contaminated or something?

 

[jbl]

When i exchanged the rear transmission fluid on mine XC70 2.5T MY 2003 and around 30kmiles it did look that black as showned from the BMW 330ci.

For you who dont believe, take a look in yours rear end transmission.

 

[Jim 5]

It didn't seem contaminated. No milky look or anything. I just thought that 30k miles was a reasonable interval for changing.

Winston's right, it would have been more scientific to use the exact same bottle. However if simlar bottles had been used, I suspect that the result would have been the same. In any case the fluid was really black, and it's not rigged because it wasn't presented as a fair and controlled scientific test.

Instead, the 1/2L coke bottle wouldn't have held all of the used fluid, I only had one of these, and it was useful for squeezing the new fluid into the diff (the little nozzle from another gear oil bottle screwed right on).

Just posted this FWIW and for interests sake, no UOA, none planned. UOA buys me 90k's worth of 30k fluid changes on the diff...barring leaks/water contamination I'm not super worried about what's going on in there provided I'm doing a reasonable fluid change interval.

My point is basically that no changes forever is not (in my view) a reasonable fluid change interval.

 

[moribundman]

For what it's worth, my OEM Audi tranny fluid and the rear differential oil looked just as dark, but I had 90k miles on the tranny oil and 120k on the rear differential fluid. I also put Red Line in both.

 

[Pablo]

I guess my point is that fluid can darken (a LOT) and still be as good (or better than) new.

Thanks for posting nonetheless. Your choice as always if you wanted to do UOA or not and your choice to change fluids. Nothing wrong with that. It's that you can't assume that 30K is reasonable OCI nor can you assume the fluid is truly shot (mind you it very well may be!)

For example - I have almost 100K miles on my lifetime fill MT juice in my 850. I have no concept of it's condition, but the unit still behaves fine. I will drain, waste money on a UOA, and refill. Soon.

 

[moribundman]

A 49er would have gotten excited looking at my old gear oils -- at least until realizing those weren't gold flakes...

 

[Jim 5]

Good point Pablo.

Is that a 850 a BMW or a Volvo?

I'm not sure whether 30k is a reasonable OCI, but I suspect that it's a safe, and perhaps wasteful oci. No matter. It makes me feel good.

For my trail vehicle, a safe interval is once per trip, but that vehicle routinely gets sunk in thigh deep mud/water. I've drilled and tapped the diffs on that one for drain plugs (since I'm changing them pretty often), and the stuff that comes out is ugly. I'm buying cheap 85w90 by the gallon for it.

 

[Pablo]

Volvi

 

[Winston]

It is a rigged photo. The old bottle is fatter than the new bottle so it looks darker.

 

[jbl]

Exchanging the fluids is cheap insurance and makes me sleep much better if not

 

[crew219]

quote:

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Originally posted by Pablo:
I guess my point is that fluid can darken (a LOT) and still be as good (or better than) new.

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2nd that, I just drained my factory fill in the gearbox on my 2006 Audi A3 with 3k miles on it and it looked dark just like that picture.

Dave

 

[Thatwouldbegreat]

If you run Redline I think that you can change every 50K.

I've drained lots of our cars at 50K intervals and the Redline looked good just a darker red than when new.

 

[Robbie Alexander]

quote:

---

Originally posted by Jim 5:
For anyone who's interested..

On the left is the stuff I drained from my diff at 33k miles in my BMW 330ci compared to the virgin Redline 75w90 in a clear coke bottle (for comparison). This isn't scientific, but it makes you doubt the whole idea of "Lifetime" fluid service. I'm sure it doesn't start out this black. Would it be good for another 200k miles? My diff isn't going to find out. I'll stick with 30k miles intervals.

---

good photo

yeah I have about 50K ish on both mine
will plan sometime in the next 25K to drain them

interesting colors

 

[PFP]

A lot of the original tranny and differential lubricants in European cars are UNDYED. You are compraing apples and oranges if you are not sure what colour the original fluid was pre-fill and you attempt to compare it to a (typically) dyed red North American product.

 

[JohnBrowning]

Not that it matters but I can tell you that the gear oil that came in my 03 Camry was clear as watter when I took it out at 10,000 miles. It had no odor other then that of base oil. Their was no sulfur smell that one associates with gear oil. It did not have any visable flakes in it when held up to sunlight. I can only assume that the particles were too small to be seen. Their also was no grit when rubed between your fingers. This is odd especioaly for a transaxle that uses the same fluid for it's diff/gears.

The lack of any additive smell really tossed me for a loop. I replaced with Royal Purple Max Gear wich is ok but is not Redline MT90 by any stretch!