Rich, thanks for all the detective work! This is very useful. I am sure
finding Herald uprights is tougher than finding early Spitfire uprights.
Do you have any thoughts on what using the Spitfire or GT6 steering arms
would do to bump steer, given that they are shorter?
Lastly, has anybody on the list used a Spitfire rack and pinion on their
Vixen TVR's? I understand they are faster lock to lock, and are virtually
identical.
Stephen
1970 Vixen
> ----------
> From: Rikrock@aol.com[SMTP:Rikrock@aol.com]
> Reply To: Rikrock@aol.com
> Sent: Saturday, July 01, 2000 8:39 PM
> To: tvr@autox.team.net
> Subject: Vixen Front Uprights
>
> Listers,
>
> I spent Friday afternoon visiting The Roadster Factory, and Classic Motors
>
> (Gene Bird).
>
> Here's what I learned about Vixen uprights and a few other parts......
>
> While the source for the uprights has been previously identified as Herald
>
> drum brake cars, the uprights on Spitfires up to Commission #15,575 are
> identical to the ones I removed from my Vixen.
>
> Dave at TRF was very helpful. I took my old upright with me, he brought
> some
> uprights to the front counter, and we compared. He didn't have a Herald
> upright, but he had an early Spit, and a GT6 part. We measured EVERY
> dimension with a vernier caliper. The early Spit upright checks out
> perfect.
> The GT6 upright dimensions match up except for the hole for the stub
> axle.
> The stub axle on a GT6 is larger diameter, by about 1/16". Looks like
> using
> the GT6 upright is possible, but it means going with GT6 bearings/seals.
>
> Spit and GT6 steering arms are considerably shorter than the ones on my
> Vixen. Dave didn't recognize my arms, 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.
>
> 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!
>
> So I bought the early Spit upright from TRF and headed to Johnstown, PA to
>
> see Gene Bird. Gene had told me he had a set of uprights in stock, I
> wanted
> to compare them to what I had just bought. The uprights Gene has are
> slightly different. Not in any of the machined dimensions, or hole size
> for
> stub axles, ball joint, trunnion , etc. but they are just a LITTLE beefier
> in
> the dimension of the stiffening rib that runs vertically, and a LITTLE
> wider
> in the area just above the threaded portion of the upright. Gene would
> only
> sell the pair, I decided to go with what I had.....I didn't think that the
>
> extra material in his parts would make much difference. The way I see it,
>
> the weak point is at the top of the threads, so the only way to improve
> the
> part is to make the threaded portion thicker, along with reinforcing the
> area
> where the threaded portion meets the rest of the upright. If anyone
> thinks
> I've missed, or got something wrong, please speak up!
>
> I'll keep you all posted on how it goes. Got to get the car back together
>
> for Giants Despair Hillclimb next weekend!
>
> Rich Rock
> Pottstown, PA
>
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