Category Archives: Original Frame Failure

bowtie6‘s Frame Failure – Revisited –

I have a few pictures with the rear section of the original frame on bowtie6.  This frame was as about as pristine as could be found when I bought my car several years ago.  There were gussets made and welded onto the frame, as well as reinforcement plates.  Every weld on the frame was gone through and reinforced.  Yet with all this work, after some 15,000 miles the frame failed.

The following pictures show the seam that failed.  Granted the rear is far from stock, but this goes to show that you can weld on the original flimsy frame but this does not guarantee it will survive.  The original frame might be OK for the anemic tractor engine that powers “original” TR6’s, but if you are going to put some real horsepower (and torque) in front of a TR6 then you might want to rethink if the frame will hold up or not.  In my case, sadly the frame gave up the ghost.

The picture above shows the Nissan R200 “long-nose” differential we used.  This diff came from a 280ZX and worked very well – however, it was quite heavy and did not have posi-traction.  The ratio was quite nice – actually a 3.90 to 1 – and this was the reason we chose the 3.80 to 1 for the solid axle currently being installed.  The picture above does not show the coilovers however, that can be found on my “old” website.  The failure happened on the left side (the passneger’s side) and the following picture shows more about it…

In the above picture you see the crack on the tower that supported the coilovers.  Here is another shot:

As you can see, the top section of the frame “lifted” off the rest of the beam.

Finally the above picture shows what the rear of bowtie6 looked like.  The diff is in the centre, with the custom made halfshafts.  The Nissan diff is held in place by the two bridges, the dual exhausts can be seen as well as the rear sway bar.  This was a nice setup and would still be in place except for the crapy Triumph TR6 frame giving away…

Seriously folks.  No joking aside.  I spent a considerable amount of resources on this “original” frame with the work we did to it.  Yet, it failed.  No, I did not abuse my car but I did get down on it in such a way that I could enjoy the upgrades.  For anyone remotely thinking about doing an engine swap using the original frame:  think and double-think what it is you want to do.

The original diff will never hold up.  Eventually after you put enough miles on it, it will fail.  Ditto for the frame.  Once again, the section that failed might have not been “original”, but we had a pristine frame to begin with.  I hope these article and pictures are of value for you.


Frame Failure – Continued

In an earlier post, I described bowtie6‘s frame failure.  Today, I have some pictures of the “issue”.  First, a little background…

Rear suspension

Rear suspension closeup

Soon after bowtie6‘s initial dismantling the frame was carefully inspected.  Although the frame was in excellent shape the rear differential mounting pins showed typical TR6 wear and tear: two of the four differential mounting pins were cracked.

Since a bigger engine was to be installed, we reconfigured the rear suspension.  A completely redesigned mount was made to hold the Nissan R200 differential as well as the coilovers that would replace the lever action shocks and springs.

The pictures on the right show the rear suspension from the passenger’s side.  You can see the coilovers, rear disc brakes and the suspension mount holding the top coilover perch.

This brings us to the following photo gallery showing the frame damage.  The frame rail has suffered a serious, unrepairable stress crack.  I have inspected the driver’s side and there too, I can see a stress fracture although it is not as severe as the one on the passenger’s side.

I’m sure there will be plenty of critics analyzing the frame failure from these pictures and coming up with all kinds of root causes for the failure.  Quite frankly, the thing is what it is.  I got 15,000 from what I thought was a very good frame but this endevour has proven to be more than this frame could handle.  The extra power the engine gained from the cam and head work plus the stress of getting hammered by the control arms caused the frame to eventually expire.  Since the rear failed this extensively, I have reason to believe other parts of the frame have also suffered stress.

As soon as the frame comes out again to see the light of day, I plan to do a full autopsy by cutting it up and documenting stress points, failure points and basically show where the frame held up and where it did not.  I’ll have that in a future article which should be very interesting to read.

And now for a little reflecting…

These frames are now 35-40 years old.  These frames are also marginal at best.  Sure, with the anemic tractor engine on the stock TR6 the frame will probably last, but not by much.   However, if anyone is thinking of adding any real horsepower then really think what you are planning to do.  These frames can be reinforced to hell and back (done that), boxed-in (done that), have gussets added (done that) and have every weld reinforced (done that), and yet they will fail.  Quite frankly, I am very happy this thing gave up the ghost – now a new frame is being built to last and handle the new ECOTEC engine with no “issues”.

Frame Failure!!

All good things come to an end.  In this case, the “original” (and I say that loosely) frame has endured a frame failure.  Yep.  There is a tear several inches long on the passenger side along the rear suspension mounts.  Upon closer inspection the driver’s side has stress marks and I’m sure it is not far from failure too.

I noticed the problem back in November of 2010.  While driving, I started hearing some unusual sounds and sure enough after putting the car on jackstands a close inspection revealed the tear.  No pictures yet, but I’ll have some soon.  Suffice to say, the frame is toast and there is no way to repair it.

Unfortunately, the TR6 frame is extremely flimsy and quite frankly it is poor at best.  And no, I’m not saying this  because mine failed.  I’m saying this for the benefit of those folks that think they can put larger or modified stock engines and the frame will be able to withstand the extra power.  Well, if you believe that you are fooling yourself.  These frames are made of 10 gauge material and is not of the best design.  It is a “U” shaped affair with an extra plate, spot welded.  Add to that years of rust from within the tubes and you have a recipe for failure.  My frame was in excellent shape when I started the project and was reinforced and properly prepared.  Even after all that attention, it failed.

I’ve had several people ask why “original” frames have held up with V8’s and mine failed.  I guess it boils down to the fact that I have put 15,000 miles on my frame and have actually stressed it enough to cause it to fail.  So if you are considering something like what I have done with bowtie6, I would highly recommend thinking all your options.

And so the next step in the evolution of bowtie6 begins…

A new, bespoke frame is in the works.  The new frame is being made of square tubing with fresh stock.  No expense is being spared on the materials.  The frame will use the factory stock front suspension components with one big difference:  the springs/shocks are being replaced with true coilovers.  The great advantage of this will be there is no more need for a spring compressor since the coilover is not only adjustable but fully encapsulated and there is spring under tension to worry about.

As far as the rear suspension?  The crappy factory trailing arms will be ditched along with the Nissan diff currently in bowtie6.  Instead I will be using an 8 inch solid axle, with four point suspension, coilovers and swaybar.  Why?  Well, the IRS is really not an option.  For the expense of new halfshafts, new diff, and all the extra “stuff”, I can have a fully posi-traction custom built solid axle that will withstand plenty of horsepower…

Which leads to the next major improvement…

Yes, bowtie6 is getting a new engine.  The 3.4 litre V6 currently in bowtie6 is pretty much maxed out.  There is no more I can do to it.  Plus the ECM is not programmable.  So what are my options?  A brand new ECOTEC 2.4 litre 177hp crate engine and matching 5 speed gearbox has been sourced.  ECM reprogramming?  No problem – this engine’s ECM is fully re-programmable.  Needless to say, the sky is the limit…

I’ll have more info on my ECOTEC in the next installment.