Hey guys, how do you know when your pushrods are bent? Are there any things (sound, handling or vibrations) to lookout for or what are the symptoms? I was just reading that this happens to M6's when you shift hard or too fast, and also when the engine is at a high rev and you down shift into a lower gear. Thanks

 

Ya I'd like to know too. A few weeks back I down shifted on the hwy from 5th to 2nd for a quick second. Also another time my floormat had my accelerator at WOT and I turned the car on for a quick sec and the thing bounced 2-3 times off the rev limiter.

 

You aren't gonna bend them by shifting fast. Bouncing off the stock rev limiter shouldn't bend them either. That's what it's there for. The only way that you likely will bend them is by downshifting at too high RPM. Go from 3rd to 2nd when you meant to go to 4th and push the RPMs past 6200 and you're gonna need to pull the valve covers, remove the rocker arms and inspect the push rods 1 by 1. Roll them on a mirror to see if they are bent. If they are, your valves might be slightly bent and you may have notched the tops of your pistons too. Run a compression test to check the valves if you don't want to pull everything apart.

The rev limiter only shuts off ignition at 6200. It is not a mechanical wall that won't allow the engine to spin faster than 6200. You can easily spin it faster by downshifting too far. I've heard of a mod that can be done with LS1Edit where you change the criteria used to activate the skip shift function. Engage the skip shift (cags) from 75-100 mph with > 75% engine load and the factory skip shift will lock you out of 2nd gear. No more accidental 3rd to 2nd shifts. Accidental 3rd to 2nd shifting is the most common way to bend the push rods. I've done it once. Luckily, my push rods seem fine. I nailed the clutch pretty quick.