Date: Thu, 24 Jun 1999 15:01:00 -0400
Reply-To: John <u1031271@WARWICK.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: John <u1031271@WARWICK.NET>
Subject: Re: Turning when hot
Content-Type: text/plain; charset=us-ascii
Dr. Rainer Woitok wrote:
>
> Steward and all you other VC beaten people :-)
>
> On Fri, 1999-06-18 10:55:55 +0100, Stewart Signol wrote:
>
> > ...
> > Hi folks is everybodies syncros as difficult as mine to turn when it gets
> > warm. Ive got bigger wheels on mine so the differences between wheel speeds
> > will be greater. I know the locks are not on.........it makes turning in car
> > parks hard!!
>
> Shot VC. Instantly go and remove the drive shaft before the VC has a
> real opportunity to ruin your front diff or rear transaxle, or both.
>
> Been there, done that.
>
> Sincerely
> Rainer
>
> '89 Caravelle GL Syncro 16"
>
> ----------------------------------------------------------------------
> | Rainer M Woitok | Phone: (+49-9131) 85-27811,-27031 |
> | Regionales Rechenzentrum | |
> | Friedrich-Alexander-Universitaet | Fax : (+49-9131) 30 29 41 |
> | Martens-Strasse 1 | Telex: d 629 755 tf erl |
> | D-91058 Erlangen | |
> | Germany | Mail: Woitok@RRZE.Uni-Erlangen.DE |
> ----------------------------------------------------------------------
Rainer,
My name is John and I need your help to understand your recent comment
to Stewart regarding syncros having difficulty when turning. To help you
understand my question, I believe the following is true:
When performing tight turns at low speeds, the rotational speed of the
front axle will be less than that of the rear axle which should cause
the viscous coupling to lock. This is normnal.
When hot, the adhesion between the warm tires and "sticky" road surface
increases dramatically which reduces the slip of the turning front
wheels. This could produce an "unusual" feel to the driver. Stewart's
"bigger tires" would only exacerbate the situation.
The "bigger tires" and parking situation could point to a steering wheel
rotation effort issue. However if his parking difficulties are a lack of
power assist, that is an entirely different matter which does not
involve the viscous coupling.
Finally I have two 1986 Syncros that have typical tire wear and feel OK.
When turning (tight radius) on cold, hard or loose material surfaces,
the drivetrain performance feels fine.
However when performing the same type of turn on hot, sticky asphalt,
the vehicle drivetrain binds and the front wheels "chirp" or jump
through the turn. I attribute this to a "trapped stress" which develops
in the four wheel drive system due to the "unforgiving" nature of the
tire/hot asphalt adhesion. This of course is quite normal and not a
reason to disconnect the driveshaft and start shopping for a front
differential (VC) assembly.
As a closing note, I have had both of my Syncros in very slippery
conditions(snowy inclines)and the rear axle would always "spin" for a
short time before the front axle would lock and start rotating, always
verifying that the viscous coupling was functioning (locking/unlocking)
correctly.
Therefore I do not understand your comments to Stewart, please respond.
JP
