What is this? Diff lock valve?

[Colesy]

Found a poorly looking valve of some sort under the rear bench seat today:



One of the plastic tubes that would have gone to the diff lock ECU has fully disintegrated and so has a large part of the valve. I'm assuming that the proximity of it to the battery has something to do with it falling apart?

The part number of it is 046 905 291A, does anyone know how much they cost from the stealer? Or does anyone have a relatively new one lying around?

Couldn't find any reference to it on the forum which I thought was strange, I guess there's a first time for everything!

[Acidburn]

I should have one you can have mate,ill have to check on sunday tho.

[Tonks4x4]

Nice one! Another boost leak fixed

[s2_bo]

The diff lock does not have a one way valve, only the aircon.

See here:

[UrS4boy]

Rear Diff Lock Info

The diff lock does not have a one way valve, only the aircon.

So sorry but that is just wrong. 046 905 291A is indeed a check valve, as shown below (Ask Katie about illustration 711-90). More details on how the rear diff lock system works electrically and mechanically are shown here: http://forums.quattroworld.com/s4s6/msgs/170940.phtml

[s2_bo]

Thanks i stand corrected.

[Tonks4x4]

I know that it is 100% a non return valve as once mine broke. So every time my car came on boost it locked me rear diff in. :wall:

[UrS4boy]

Thanks i stand corrected.

No problem. The diagram you posted was no doubt correct for the engine bay. It just didn't extend that pink "line" far enough out to the rear diff area to warrant showing the 046 905 291A check valve.

[Colesy]

Cheers guys, good to know what it is. If you do find one Pete, that'd be great.

[andy10v]

I know that it is 100% a non return valve as once mine broke. So every time my car came on boost it locked me rear diff in. :wall:

Interesting to drive?

[Tonks4x4]

There was a brown trouser moment after a steep left hander taken at speed. Just after the apex I hit the gas and as soon as it hit boost the rear stepped out, not expecting it to act like that it caught me off guard but no harm was done

[UrS4boy]

Thanks i stand corrected.

S2_bo: I was poking around my photo files looking for something else entirely and stumbled upon this, done by Paul N. back in 2003. I have added it to my Rear Diff Lock post (with a comment related to Tonks4x4 "brown trouser" moment):

http://forums.quattroworld.com/s4s6/msgs/170940.phtml

[martinws]

There was a brown trouser moment after a steep left hander taken at speed. Just after the apex I hit the gas and as soon as it hit boost the rear stepped out, not expecting it to act like that it caught me off guard but no harm was done

I might just plumb mine in like this. My centre diff slave cylinder thing is knackered anyway.haha.