Well, actually, no. The PowrLok, although a very old design, (ours is from a
Studebaker Lark V8) is actually a really good one. It uses clutch discs and
cones to produce a very progressive and, usually, smooth operating unit. The
problem is that it does tend to misbehave and chatter when very hot, like
after 15 minutes flat out through the streets of Gander, Newfoundland, if
the correct lubricant (whale oil reputedly) is not used. The lube is
available from Ford dealers.
The other problem is that Powr Loks are getting hard to find. This is what
the PowrLok looks like inside.
http://www.autohobbydigest.com/image.php?dana-f6.jpg
As I understand it the problem with the Quaffe unit is that if you
completely loose traction on one wheel that wheel just spins like an open
diff.
I think the ratchet types are the Detroit Locker and the infamous Hewland
"Cam and Pawl" types.
Michael Salter
www.precisionsportscar.com
-----Original Message-----
From: owner-healeys@autox.team.net [mailto:owner-healeys@autox.team.net] On
Behalf Of rjhco
Sent: Monday, May 09, 2005 11:15 AM
To: 'Rick'; healeys@autox.team.net
Subject: RE: Limited Slip Diff
Rick:
I have a Quaife in my BJ8 Rallye car. The Quaife design differs from the
Powr Lok design. The Powr Lok engages and disengages a set of ratchets as
needed for traction (is my memory correct, Mike?) so, it can transfer
unsettling sounds and vibrations, especially at slow speeds in tight
corners. The Quaife is continuously engaged since its design employs a
series of gear sets that automatically provide gear ratio resistance when a
wheel begins to slip.
Pros for Quaife:
* Relatively easy to install. Complete disassembly of the rear end
and replacement of the original differential in the pumpkin required. Does
not require resetting the crown and pinion.
* No ratcheting noise
* Smooth operation
* Very strong and well made
Cons for Quaife:
* $$$$ Last I looked it cost about $1,400 just for the part at my
source.
* Slightly heavier rear end than original
* Uses up a little rear wheel hp spinning up all the gears
* AH Quaife was real hard to obtain. May be available now.
* May not be legal for all vintage events. Some sanctioning bodies
require "chiclet" type or ratchet type LSD.
Put an LSD in your car only if you have seriously upgraded your hp and need
the traction. If you are spinning a wheel a lot using factory hp, follow
Mike's suggestion and consider reworking your suspension and car balance
first - correct sizing of sway bars, perhaps an adjustable rear sway bar,
rework your leaf springs, check your torsion bars (or add them if an earlier
car), consider adding a panhard rod with heim joints if you have a BJ8,
check your rear shocks, consider tube shocks all around.
One final thought if your entire car is twisting, check you chassis along it
entire length for rust and thin metal.
Best regards,
Jim Hockert
Dallas, TX
BJ8 Rallye
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