My mechanic told me I need a new front drive shaft and transfer case for a 2004 X5 I bought for cheap. I found this product on the internet and it made me think twice. It seems the stock drive shaft only reaches 3/4" into the female side on the transfer case. These shafts seem to advocate for deeper penetration (lol) by up to an inch. This sounds like you'd get past the stripped splines and now you'd have 1" of contact where before you had 3/4". As a fix it seems good, but it seems even better to proactively replace it.
Has anyone done this mod or bought a part like this before?
https://www.ebay.com/itm/BMW-X5-e53-...Cclp%3A2334524