Asgeir Nesoen wrote:
> >Hi Dave,
> >Strikes me that the thing has to be exactly aligned <Snip>
> Well, anyway, I have had trouble (through times) fitting the two driveshaft
> parts in-car, and when I have taken the parts out, they have fitted like a
> glove.... Strange how much more difficult things get when you're on your
> back under your car with some oil and dirt in the corner of your eye, isn't
> it? Hehe...
You're not kidding there- it's like the way MIG sparks always end up in
your socks...
>
> >Re. the UJ thing. How can the the shaft be in height other than with the
> >car at rest?
>
> Well, it doesn't matter how it is while standing still, because there is no
> load on the U/Js. However, the car will have the same height or suspension
> travel when moving, so the neutral balanced situation will be the
> prevailing one also when driving.
Hmm...perhaps on average but the rear wheels do move up and down
individually in response to bumps.
>
> And I am talking about the angle of the UJs, i.e. if the driveshaft goes in
> a straight line from the diff and to the wheel, and not at any angle. It is
> the angle that wears the UJ, the same can be said about the propeller
> shaft. The wear is definetely bigger with the O/D cars than manual, and
> this is because the gearbox has been lowered on the O/D cars, and this
> makes the propeller shaft more off-line than it is with manuals.
I agree with the basic priciple here, i.e. the static alignment should
be reasonably straight. IMHO, there's no way to maintain that alignment
even under mild suspension deflection.
>
><Snip>
> When you corner, you won't normally do this under heavy acceleration (but
> on a track you would, and the wear of the driveshaft UJs would be
> significant while cornering). The outside would compress and the inside
> expand, this would make both UJs heavy loaded AND out of line.
Huh? What about the plunging joint? That's what the splines are for.
Cars which use the shaft as a link (e.g. Spitfire/Herald, E-Type) would
suffer joint compression and extension and their UJs do croak. The TR
shaft is designed to change in length with suspension travel..leastways
when the splines aren't locking under power :-)
Equally, you could say that the propshaft joints on live axle cars have
a much harder life. That said, the shorter the shaft, the greater the
angular deflection for a given travel (e.g. with O/D as above.)
Overall it sounds like a good case for using tripode (CV) jointed
shafts, such as Barrat's used to sell, and as (I belive) does Chris
Witor-his are apparently modded production items for which the diff side
flanges need machining. Either way, you get a lot of UJ's for the price.
Thanks for an interesting discussion.
>
> Cheers.
Dave Hill
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