Tailshaft housings are usually cast aluminum that expands 11.7 millionths of
an inch per inch of length (or diameter) for each degree F. (billet
aluminum is 13) Ordinary steel is around 8. That means for every degree in
temperature rise a 3" OD seal will lose 3.7 x 3 = 11 millionths of its press
fit in an aluminum tailshaft housing. 100 degrees; .0011 inches on the
diameter. At some point the seal will no longer have enough press fit to
resist the combination of loads from shock and vibration, torque on the seal
from friction and internal pressure from the transmission oil pushing
against it. And note that if the temperatures ever get much above 325
degrees F the aluminum will start to "relax". But that seems unlikely
because the rubber in the seal will probably start deteriorating first. (I
think). Also note that if you don't have a clean straight installation of
the seal you may distort its steel case and not have as much press it as you
think. To me the idea of a couple of retainer tabs on a stainless steel
hose clamp sounds pretty good rather than wasting time trying to "engineer"
some other solution.
Ed Weldon
----- Original Message -----
From: "Benn" <karhu@california.com>
To: <land-speed@autox.team.net>
Sent: Wednesday, June 27, 2007 10:10 AM
Subject: Re: [Land-speed] trans hose clam
> Sure sounds like the interference fit is insufficient if the seal falls
> out... Benn
> ----- Original Message -----
> From: <Askotto@aol.com>
> To: <BobH@roehrigengineering.com>
> Cc: <land-speed@autox.team.net>
> Sent: Wednesday, June 27, 2007 8:29 AM
> Subject: Re: [Land-speed] trans hose clamp
> > In a message dated 6/27/2007 6:36:04 A.M. Mountain Daylight Time,
> > BobH@roehrigengineering.com writes:
> > Being involved with a few nascar teams. The hose clamp usually has a
> couple of small angle ears on it to help keep the seal in the
transmission.
_______________________________________________
Land-speed mailing list
http://autox.team.net/mailman/listinfo/land-speed
|