DiFi Drainage: Is It Finally Over?

Hello,

For the DiFi (differential) replacement on the 2004 ASZ Polo, I received a part from VAG with the correct part number (at least, that's what was printed on the packaging).
The hose connectors and the "Knackfrosch" (likely a specific product name) fit perfectly, but when the new filter is inserted into the holder, it simply falls down until the hoses rest against the edge of the holder.
The comparison with the old DiFi (on the right in the attachment) shows why: A whole section is missing at the bottom, including the drainage screw!

I was able to create a suitable spacer to hold the new DiFi in place, but I still wonder why the DiFi is no longer supposed to/allowed to be drained.

Some filters have something like a sediment trap that collects and retains the water. Assuming the recommended replacement interval, this should be sufficient .

Hi ULF, I think they didn't give you the correct filter. It can't be right that the filter is resting on the filter holder with the hoses on top, instead of on the lower plastic supports as intended. After all, it and the holder are installed in some VAG vehicles.

"Exposed hoses create a new potential point of friction and, consequently, a future source of errors with this filter installed. I would object to this! If the OEM filter is actually intended to forgo water removal, then it should at least be designed in such a way that its fit is no worse than the previous part. If necessary, one may have to forgo the OEM part in the future and choose a supplier that continues to offer the previous filter design."

The same applies to the Sharan model mentioned. When you buy the filter as an original part, you now often get a filter without a drainage function. However, the Difi filter that came as standard equipment did have this function.
If I buy the Difi filter from Mann+Hummel as part number WK 853/11, will it be the correct one?

RedR32 wrote:

It can't be true that the filter, with its hoses on the filter holder, rests on the filter holder itself and not on the lower plastic supports, as intended. After all, it and the holder are installed in some VAG vehicles.

It also seems that there are several variants of the holder:
My Ibiza has the exact same short filter (which, when I bought it with approximately 24,000 km, was definitely still the original part from the factory), including the holder, but the holder prevents it from rattling downwards.

I don't plan to return the filter I bought for the Polo, because the issue with the spacer seems to be resolved. I will check the spacer several times in the near future to make sure it hasn't fallen apart - and hopefully, if it does, I'll notice it before the hoses get worn through .

I can't find the part number 6Q0 127 401.

If the new part is a 6Q0 127 401 H, it should have already been replaced with a 6Q0 127 400.

He should also receive a 6Q0 127 401 B.

Something's not right.

dieselmartin wrote:

I can't find the 6Q0 127 401.

That was the original equipment.

Quote:

If the new one is a 6Q0 127 401 H

, it should have already been replaced with a 6Q0 127 400.

Quote:

Correct!

That's exactly what's written on the packaging.

Quote:

Furthermore, he should get a 6Q0 127 401 B.

That might be the mechanically compatible high-performance version.
The shorter one is actually my preference due to its power-to-weight ratio, because my hollow spacer made of plastic certainly weighs less than the metal casing around the missing height, including the internal components and the dead volume of diesel.

Quote:

total diesel volume

Especially at the front! And that's on top of the already head-heavy diesel engine.

What does the VW workshop do about it? Nothing, they just swear.

dieselmartin wrote:

I can't find the 6Q0 127 401. If the new part is a 6Q0 127 401 H, it should have already been replaced with a 6Q0 127 400. He should also receive a 6Q0 127 401 B. So, something isn't right.

Yes, the Bosch AT list is probably incorrect!

6Q0 127 401 B or 0 450 905 322 would be correct. However, there is no longer a use for it in the Bosch list.

Has anyone in Germany actually found or drained water from a filter in the last 10 years? I certainly haven't since 1997.

christians wrote:

Has anyone in Germany actually found or drained water from a filter in the last 10 years? I certainly haven't, not since 1997.

Yes, just 3 months ago... 2 pumps completely failed, and there were about 15 instances of vehicles being stranded... } The gas station probably had a significant amount of water in the tanks... }