Russell Talbot wrote:
>
> Rich
>
> It sounds like you're nearly there with fixing the Vixen. Good luck
>
> This latest discussion inspires a couple of rambling thoughts.
>
> I beleive that the GT6 uprights are the same as the Vitesse ones and can be
> used but you have to have the hub machined to take the larger bearings - not
> sure where I read that - John's website maybe - but as you say they are the
> same size at the threads where they fail anyway. I have seen one fail from
> the passenger seat of a Tuscan - a metallurgist who examined it for me said
> that it was a classic fatigue fracture caused by bending - I wonder whether
> a very small amount of wear (such as caused by insufficient lubrication)
Indeed. As I said previously, the failures are caused by massive
lateral
loads when putting the steering on full or near full lock. DO NOT do
it!
It is not a Taxi but has the lock of a Taxi! Most/all front upright
failures are caused by too much steering whilst low speed parking type
manoeuveres. If not notice, when you put the car on full lock, it will
go straight with the tyres scrubbing like made. This puts a huge load
on the uprights especially in the dry.
I broke one on a hairpin bend (should have used the handbrake) whilst
on a rally in Devon.
> adds to the bending by permitting some movement and causes premature
> failure. Since then I have had to replace a couple of trunnions on
> different cars and have seen that with a new trunnion and an old upright
> there is generally some free play and so have taken the precation of
> replacing the upright as well.
Good idea.
>
> I am intrigued by the steering arm question because I have been puzzled for
> years as to why there are two steering rack mounting positions. The
> original arms are apparently Standard 8 ones but modified (bent) by TVR to
> clear the brake disc.
> If you fitted Herald arms and moved the rack to the rear position wouldn't
> this have the same effect as fitting a quicker rack? Would this be any
> benefit? What would be the effect on the bump-steer that the Vixen is
> famous for? Has anyone tried it? Has anyone tried raising or lowering the
> rack to sort the bump-steer?
>
There is no benefit to be had by moving the rack backwards or
forwards. It needs
to go upwards. See "Prepare to Win" by Carroll Smith, Chapter 10.
Do the measurements with the string and you'll see why!
> No one's taken up John's invitation to discuss lubrication but just for fun
> I'll ask why do TVR and Triumph recommend different lubricants for the same
> parts.
Good question. I have been told that the channel size of the thread
varies on different triumph uprights. The larger the thread, the lower
viscosity should be the lubricant. Most people say use a mix of
EP-90 and grease.
I use AMSoil synthetic brearing grease and pump through to new grease
every couple of weeks depending how wet the roads are.
Regards,
John
>
> Russell
>
> ----- Original Message -----
> From: <Rikrock@aol.com>
> To: <webmaster@ukmotorsport.com>
> Cc: <russell@hockerley.freeserve.co.uk>; <adrian@exactly-tvr.demon.co.uk>;
> <mtowns@westsussex.gov.uk>; <tvr@autox.team.net>
> Sent: Monday, July 03, 2000 2:44 AM
> Subject: Re: Vixen Front Uprights
>
> > In a message dated 00-07-02 18:25:43 EDT, webmaster@ukmotorsport.com
> writes:
> >
> > <<
> > and didn't have a Herald arm for us to
> > > look at, but we looked at a TR4-6 steering arm and it is completely
> > > different. It will not bolt up to the Vixen/Herald/Early Spit
> upright--the
> > > hole spacing is wrong.
> >
> > Correct.
> >
> > >
> > > The caliper mounting plate on the Vixen is from a TR4-6, but is
> modified to
> > > fit the Vixen/Herald/EarlySpit upright---four new holes are drilled in
> it
> > to
> > > make it fit!
> >
> > As far as I know the TR2-6 caliper mounting plate (133499, UK, n/s)
> > (133500, UK, o/s)
> > go straight onto the normal uprights (209222, 209223 : sides swapped)
> > without
> > any modification.
> > >
> >
> > 209222 and 209223 are the part numbers on the early Spit uprights from
> TRF!!
> > Could it be that the early Spits were made with drum brake Herald
> uprights??
> >
> > As far as the caliper mounting plate goes, a TR4-6 part would have to be
> > redrilled to fit the Herald/early Spit upright, otherwise a TR4-6 steering
> > arm would fit??
> >
> > After installing my new upright I found a previously undetected
> problem...my
> > lower A-arm is slightly bent!! Anyone got a good one to sell? (passenger
> > side of a LHD car)
> >
> > Rich Rock
> > Pottstown, PA
> >
> >
--
Dr John Upham, The UKMotorSport Index,
http://www.ukmotorsport.com/, webmaster@ukmotorsport.com,
Voice: +44 (0) 976 634 053 (W), Voice: +44 (0) 125 287 2551 (H),
Voice: +44 (0) 976 634 053 (M)
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