rene4406 posted:panteradoug posted:The torque number is to load the bearings, not necessarily to keep the nut tight. You can do that with Lok-tite.
If you aren't torking to 400 then the bearings aren't loaded correctly.
It's the factory's number, not something out of the blue or from outer space. Modify it at your own risk.
Preload is only justified with tapered roller or possibly angular contact bearings, not with simple ball or deep groove bearings.
At least, it was like that when I was studying in an engineering school in the early 70s, when the Pantera were produced.
I agree, I would expect a torque rating like that to be used with tapered bearings. I don't know where 400lb-ft is required at all UNLESS the consideration (a paranoid one maybe) was that the designer wanted the bearings and the spacer for all intents and purposes to act as a single machined piece and he had previous experience maybe from Formula 1 that a torque like this was the safest bet?
I don't like that much torque particularly considering that the axle hardness to begin with is questionable (shown to be too soft and not hardened adequately by the original manufacturer) and worry that maybe I'm stressing out the threads and stretching the axle by going to that much torque?
Still, I am not Giancarlo Dilara. If he tells me to jump, my only question is how high?
I like your creative thinking on your modification but am concerned for 1) the crushability/durability of that lock washer and 2) something I'm missing that Dilara knows and I don't.
How much torque are you going to use with your modification? 400 I think is ridiculous to begin with? How can you calculate a preload with the modification? If I knew why it was 400 to begin with then maybe an educated guess would be in order?
Formula 1 cars of the era were only about 450hp and weighed around 600kg (1320lbs). Maybe the Pantera rear uprights are a common F1 design of the time?
A lot of experienced designers use an empirical method. They use what they know works. If it breaks, make it thicker/stronger, then if it doesn't break, they give it to a mathematician to write a predictable formula for it. Does that sound like Dilara? I don't know?
Oh...I give you high credit and kudos for the courage but I stand by my original comment of "modify at your own risk", because of all of the above. ^. No offense intended