I have a 2007 Silverado Hybrid and it has been in the dealership numerous times due to serious jolts while driving (feels like popping the clutch on a manual transmission). I thought it was a transmission problem, but my tech says it isn't because when it happens the computer says it's still in gear and not shifting. During all this my torque converter went out and a prong on generator broke off?
It has now been at the dealership for over a month this time. My tech is beside himself and GM is saying that this jerking is a normal function for the hybrid system. I personally think they are nuts! It is so bad that if anyone test drove it I guarantee they wouldn't buy it!
I would think there would be many complaints if this was a normal function of the hybrid system. Have you heard of anything like this?
I haven't heard that type of complaint on a 2007 Silverado hybrid. Not related, but there has been noise about an electric motor "whine" while driving GM's new full-size hybrids. The revolutionary two-mode hybrid system which boosts both city and highway fuel economy utilizes two electric motors inside a rear-wheel-drive transmission. That means both motors are tucked in the chassis's center hump just a few feet from driver and passenger ear level. It's not excessively loud, but you do hear it. And if it's a $75k Escalade Hybrid, you really hear it.
In this case I spoke directly with the owner of the Silverado Hybrid in question, equipped with a somewhat primitive hybrid system. This truck has a real problem, yet intermittent and hard to diagnose. The owner has been impressed with the dealership's courtesy and determination in getting it fixed, but there has been a lot of truck downtime involved already -- GM tech support suggesting it may be a normal condition hasn't helped.
Damage to the drive motor/generator and torque converter which are both located between the engine and transmission has already been detected and repaired, without fixing the problem. A stab in the dark is an alignment problem between the engine, bell housing (which houses the hybrid drive motor/generator) and the transmission -- possibly a broken or missing dowel pin, or even a crack in the bell housing itself.
Another suspect would be excessive crankshaft end play causing the crankshaft, along with the drive motor/generator and torque converter, to walk back and forth. I'm gonna stay in touch with the owner and update everybody on the final conclusion.