3 VC function questions

Three interesting questions need answering please for newbie
Syncro owners such as I with no difflocks.

Does the VC kick in in reverse gear as it does in forward gears when a
rear wheel starts slipping? If not, as I suspect it does not, then that
makes for some "interesting" recovery issues when stuck.

When traversing say ... muddy conditions, you find both wheels on one
side are spinning uselessly, will the VC kick in and drive the Syncro
using only the 2 wheels on the other side?

And also, maybe even do that with only 1 wheel gripping?

Cheers and thanks

Ken
Ken,
 
1.  The VC is permanently active and bi-directional.  It works in both forward and reverse.  It doesn't "kick in" as such because it applies drive effort at all times, but the nature of the VC is that a difference between input and output speeds causes the silicone fluid to heat up rapidly, thus transmitting more effort from the driving side to the driven side.  If you are reversing and one rear wheel starts to slip, drive is still be supplied to the front axle. 
 
2.  If you have no diff lock/s and you get both wheels on one side slipping, you have no drive effort available.  The VC only operates to minimize the speed differences between the front and rear axles.  It has no effect side to side, which is why diff locks are used.  The diff lock locks both wheels together on the one axle.  (Very few Australian Syncros have a front diff lock.  They were available as an option.  The front lock is certainly effective but only at the extremes of grip.)
 
3.  The only way to get drive with only one wheel gripping is via a rear diff lock if it is a rear wheel that has grip.  If the vehicle has a front diff lock, it is always in conjunction with a rear lock.  If only one front wheel has grip and the front diff lock is engaged, drive will be provided to the front axle via the VC.
 
Les
----- Original Message -----
From: Ken
Sent: Friday, April 21, 2006 1:37 AM
Subject: [Syncro_T3_Australia] 3 VC function questions

Three interesting questions need answering please for newbie
Syncro owners such as I with no difflocks.

1.  Does the VC kick in in reverse gear as it does in forward gears when a
rear wheel starts slipping? If not, as I suspect it does not, then that
makes for some "interesting" recovery issues when stuck.

2.  When traversing say ... muddy conditions, you find both wheels on one
side are spinning uselessly, will the VC kick in and drive the Syncro 
using only the 2 wheels on the other side?

3.  And also, maybe even do that with only 1 wheel gripping?

Cheers and thanks

Ken



Thanks Les, well that clears that up pretty good with only one
unresolved concern.

I preface my past experience below by saying I believe and so does my
mechanic up here that my VC is functioning ok. However, soon after I
bought the van I took it offroad and had reason to reverse up a slope
... dry dirt and short scrubby weeds and bush grass .... the rear wheels
spun and I got no help from the front, That's why I asked does the VC
work in reverse. Maybe I should repeat this test and monitor it more
closely and also for my own protection, carry out the VC integrity test
in my garage.

Cheers

Ken


--- In Syncro_T3_Australia@yahoogroups.com, "leslie harris"
<leslieharris@...> wrote:
>
> Ken,
>
> 1. The VC is permanently active and bi-directional. It works in both
forward and reverse. It doesn't "kick in" as such because it applies
drive effort at all times, but the nature of the VC is that a difference
between input and output speeds causes the silicone fluid to heat up
rapidly, thus transmitting more effort from the driving side to the
driven side. If you are reversing and one rear wheel starts to slip,
drive is still be supplied to the front axle.
>
> 2. If you have no diff lock/s and you get both wheels on one side
slipping, you have no drive effort available. The VC only operates to
minimize the speed differences between the front and rear axles. It has
no effect side to side, which is why diff locks are used. The diff lock
locks both wheels together on the one axle. (Very few Australian Syncros
have a front diff lock. They were available as an option. The front lock
is certainly effective but only at the extremes of grip.)
>
> 3. The only way to get drive with only one wheel gripping is via a
rear diff lock if it is a rear wheel that has grip. If the vehicle has a
front diff lock, it is always in conjunction with a rear lock. If only
one front wheel has grip and the front diff lock is engaged, drive will
be provided to the front axle via the VC.
>
> Les
> ----- Original Message -----
> From: Ken
> To: Syncro_T3_Australia@yahoogroups.com
> Sent: Friday, April 21, 2006 1:37 AM
> Subject: [Syncro_T3_Australia] 3 VC function questions
>
>
> Three interesting questions need answering please for newbie
> Syncro owners such as I with no difflocks.
>
> 1. Does the VC kick in in reverse gear as it does in forward gears
when a
> rear wheel starts slipping? If not, as I suspect it does not, then
that
> makes for some "interesting" recovery issues when stuck.
>
> 2. When traversing say ... muddy conditions, you find both wheels on
one
> side are spinning uselessly, will the VC kick in and drive the Syncro
> using only the 2 wheels on the other side?
>
> 3. And also, maybe even do that with only 1 wheel gripping?
>
> Cheers and thanks
>
> Ken
>
>
>
>
>
>
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