The consensus for rear castle nut torque among some friends with fiberglass dune buggies that see challenging off-road several times a year is 280- 300 ft. lbs. As a group we do 3 weekends, anywhere from 2-4 days a weekend, each summer, some do day trips out of town as well and I don't remember the last time anyone was plagued with stripped splines. I know some of the local VW street crowd do about the same, and this includes a couple of guys with 11 and 12 second cars. And don't forget the cotter pin!!
@Stan Galat posted:...We're pushing well past the design parameters (assuming there were any) for aftermarket VW parts, which in most cases don't even approach the quality of OEM parts in a German economy car last built a half-century ago.
Tearing through the mountains at twice the posted speed limit was never what the Sainted German Engineers imagined, and the suspension and brake parts were never designed for how we use them. The absolute weakest of weak links is how the rear hubs are fastened to the car. It's a perfectly fine setup for profiling, and comically inadequate for how we use them...
The advice Gordon and Al give regarding the torque of the castle nut is good, but I've learned (out here by myself) that 217 lb ft or 250 lb ft (or whatever) is the barest minimum. You do you, but I'm torquing that particular nut as tight as I can get it. The chances of stripping it are near zero, and the downside of it being too loose is exceedingly bad. I go to at least 400 lb ft, but I'm a spot-torque man on this particular piece (torque it until you see spots). In this instance, I'd tighten with a breaker bar and cheater, and just check it with a torque wrench set to 300 lb ft. I just want the wrench not to click.
Other, better, more careful professional mechanics will be aghast at my ham-handed approach, but it's worked for me, and I'm a lowland gorilla who drives like his scalp is on fire.
Stan brings up a couple of great points- Dr. Porsche and the engineers at VW never imagined we'd be doing the things we do with their budget commuter car for the masses, and with a lot of aftermarket parts these days not even approaching OEM quality we have to come up with our own solutions to problems the factories guys simply couldn't begin to anticipate.
And Stan- is that 400 ft. lbs. lubed or dry?
@El Frazoo- Glad you caught it before it stranded you, Kelly!