u/slowerisfaster

2016 GTI with Performance Pack - 151,000 miles

I found the source of my groaning noise while in motion. The front differential lock is leaking fluid and is probably nearly empty by now.

This is my fault. When I had the transmission out to change the clutch last year I thought it would be a good idea to change the seals on the VAQ diff lock; cause you know, while your in there. Anyway, I didn't realize how difficult it would be to get the seals in and out without the VW special tools, but I did my best. But I was never sure if I got them all exactly in the right place, especially the one on the side shown in the photo because I forgot to take measurements. Clearly I didn't get the position of the seal right, or I damaged it trying to get the axle flange back on.

So now my dilemma is this. I've been driving it with the noise for quite a while now. So its likely been low on fluid for quite a while. Does this mean the entire unit is toast? Could I get away with trying to reseal it again? My gut tells me no; it probably needs to be replaced.

Of course, it's VW so a new one is pretty darn pricey ($600 is the cheapest I've found). I believe the correct part number is 02Q409055D. I found a used one on Ebay for $200 that is listed for a 2017 GTI, but the part number is 0D9409055A. They look nearly identical, but I don't know if it would fit or what the differences would be. Does anyone know if there are any major differences or do you think this used one would work?