[Fot] TR CHASSIS FATIGUE - A CAUTIONARY TALE

[Larry Young]

I don't think anyone mentioned that the IRS cars are notorious for 
weakness in the mounts for the differential and the brackets up front 
where the lower A arms mount.  These usually fail without the added 
stresses of racing.  I did a frame off restoration of my TR250 last 
year.  It has resided in Oklahoma (a relatively dry state) and been 
garaged for all but its first 6 years.  It body was relatively rust free 
as Triumphs go (solid floors, etc).   After repairing and reinforcing 
the usual problem areas, I noticed a  very small pinhole on the bottom 
near the center (called the T-shirt) area.  The thin metal was only a 
few square inches and may have been partially because it had scraped 
bottom there at some point.  Since these frames rust from the inside,  I 
wonder how many are out there with thin metal, which has not yet rusted 
all the way through?  It seems that a visual inspection is not 
sufficient. Is there some sort of sonic testing device which could be 
used to check it over.
Larry

On 1/10/2013 5:47 AM, yellow04 at tr4racer.com wrote:
> Good question.
>
> The ladder frames under the TR2-TR4 seem to be much more rust resistant than
> the wishbone frames under the TR4A-TR6. I have come across numerous ru
> project cars over the years, and have seen plenty of rusted out TR3's and
> 4's with what appear to be good frames, but I have never seen a rusty TR4A,
> 250 or 6 that did not need extensive frame work. I should add I have come
> across plenty of nice wishbone framed Triumphs sitting on frames in dire
> need of attention.
>
> I know the spring towers and cross members are different between the ladder
> and wishbone frames, and I believe the newer wishbone frame design is more
> robust. However, because of their propensity for rust, I'd venture a guess
> that the wishbone framed cars share the probability of failure in the areas
> Joe mentioned.
> A
> Remember, the stess we put on these cars running them on track with today's
> racing tires is way beyond what the designers ever dreamed possible. You
> need to reinforce many key areas, keep the frame clean, paint it with
> something that will not hide cracks, and be very diligent with close
> inspections between race weekends.
>
> Henry
> yellow04 at tr4racer.com
> ----- Original Message -----
> From: "sherry robyn" <sherryjimmy6116 at att.net>
> Subject: Re: [Fot] TR CHASSIS FATIGUE - A CAUTIONARY TALE
>
>
>> Do TR6s (1974) have this weakness also?
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