Re: Where's my LSD?

From: Michael Maskalans (dml@tepidcola.com)
Date: Tue Feb 08 2005 - 18:45:20 EST


On Tue, 8 Feb 2005 david.clement@verizon.net wrote:

>
> Depends on what you mean by "full locker". The serious off roaders use a
> differential that uses air to lock and unlock the differential. In the
> locked postion the differential is for all pratical purposes a spool and
> has no diferential action. In the un-locked position the differential is
> an open, there is no in between.

Only if they subscribe to the ARB philosophy of "complex = good" and have
lots of money to spend. those who are truely serious either 'run what
they brung' and weld their spider gears becuase they don't care about
street handling or use a full spool since it's the strongest carrier type
you can get.
Also, there are electronically actuated selectable lockers, and selectable
lockers that act as a limited slip when unlocked (IIRC the Detroit
Electrack is one of these).

>
> The "Detroit Locker", Power Trax and other such mechanical racheting type LSDs
> still perform the same function as a clutch type LSD. The main advantage is
> there are no clutches to wear over time and the disadvantage is they are not as
> smooth and tend to be noisey.

I would not draw the comparison between a limited slip and a mechanical
locker. I think it is far more accurate to say that a locker is a spool
that allows the outside axleshaft to overrun the driven speed. Limited
slips are of no use when one tire has zero traction, lockers and spools
both work in that same situation. Limited slips are great on the street,
lockers can be a bit squirrelly on the street if you apply power in a turn
and the locker tries to lock up while applying more power to the inside
tire, and while predictable a spool is nearly useless on the street due to
drastically increased tire wear and an increased turning circle.

>
> I believe the new gear type LSD's (Quaifee and the one being advertised by
> Auburn)

called heilical gear LSDs
   (assuming I can spell correctly)

> actually route the torque to the wheel with the most traction, so these
> will allow for the different wheel speed for going around corners but won't
> allow one wheel to be stationary while the other spins. These are real big
> bucks and there is limited availability.

I'm not sure if they are capable of directing more power to the slower
wheel, but I do know that since they depend on gears instead of clutches
they can be set tighter without burning them up and you don't need to use
friction modifier in your gear lube with them.

--
Mike Maskalans
'98 CC SLT SFA 4x4 5.2 PBA
(1998 club cab super luxury trim four wheel drive v-eight solid axle swap
powered by acronyms)



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