Ross Balancer Complete Failure

[ItzGenX]

Anyone ever hear of the Ross Tuffbond (Omega) balancers failing? Mine just completely came apart this weekend while powering down the highway. I was running on wastegate spring pressure of 6psi @ 5k RPM when it happened. The balancer has less than 3k miles on it with only a few high RPM pulls to 8500 of the 9th redline.

 

I am in the warranty process where I have to send this thing back to Ross for inspection. However, I would love to hear thoughts and stories regarding balancer failures of this caliber.  

My engine stalled the second it happened since I use the trigger kit.  I guess this kind of helps prevent further collateral damage, so there's a silver lining.  I run all of the standard accessories that belong to the engine; alternator, water pump, ac, power steering.  The only thing I can think of is I can feel slightly more vibration in the car when cruising with ac versus it off.  Possibly the ac compressor compression strokes in it transferring too much force back into the balancer and eventually making the bolts sheer like a constant impact gun on it?  The only things that can transfer load into the outer sleeve are the alternator, water pump, and ac. My belts weren't too tight either. I usually go easy on belt tension in fear of ruining front main bearings on engines.

 

I run a Brian Crower 2.8L fully counterweighted bottom end, and the engine is solidly mounted to the car.

 

See photos below:

 

 

Edited June 18, 2019 by ItzGenX

[burn4005]

Bolts either over torqued to yield, or they came loose and the clearance was enough for the shell to oscillate on the bolts to the point of fatigue.

I've seen an ATI1000 balancer do the same thing.

[ItzGenX]

The sides of the bolt threads and countersunk holes do not show side thrust damage from oscillations. If it was, it didn't happen for long enough to show. I guess it was a bad set of bolts or torqued beyond it's yield point.

 

I never touched the inner bolts at all. The only bolts I touched were on the outer ring to install the reluctor wheel.  

 

Seems to me there needs to be either more than 6 inner bolts, change to larger diameter bolts, or use a stronger bolt.

 

So this even happens to other balancers? Wow, was I surprised when it let go. I was thinking "please don't be a hole in the block from 6psi...."