waiting for a
Join Date: Jan 2007
Location: Buckingham, UK
Re: 3.2 V6 Blown Diffs
I heard via a friend/ex-Alfa technician that, as I mentioned before, the gear oil is a contributing factor. Apparently the gearboxes can loose quite alot of oil, which leads to premature failure. The solution that will void your warranty is to add a gearbox oil cooler. Without a pump it's ineffective, but you do increase system capacity. I think the better option is to have the gear oil changed/topped up at the same interval as the engine oil.
I also can't escape the theory that the VDC has something to do with it. It seems that not many track cars are doing diffs, and I imagine they all turn TC/VDC off when racing. And very few 156's have had diff trouble, and they don't have VDC at all. My diff went on a wet road, which had very little traction = low load. I did have a little wheelspin before the bang though.
It just seems more and more plausible to me that the combination boarderline design, Active VDC grabbing brakes and poor lubrication are causing the failures seen by people so far in 147's and at least one GT.
I wonder if I can talk to a higher up at Alfa about it. Q2 sounds like a good idea at this point. It will force less wheelspin in the first place, so the VDC isn't working as hard, but can it cope with the load when VDC does kick in, or are it's internals as delicate or more so than the standard diff? Who has the answers?