Vibration

[stroked67]

Got done after a cruise last night, and I was pretty heavy in the throttle, but when I got home I noticed a vibration during deceleration.  I was sitting in garage revving it to about 2500 and during deceleration from about 2000-1400 there was a vibration.  Harmonic damper? Torque converter hot or Bad? Any thoughts?

[WConley]

Some thoughts...  I'm assuming this is a new vibration that just appeared after you romped on it.  I'm also assuming it appears when you rev it out of gear, car not moving, so it's not the driveshaft.

• The torque converter may have thrown a balance weight. 
• The outer ring of the damper may have spun a bit (if externally balanced for your stroker.  Check the timing with a light and you'll see that right away...
• You could have a busted or loose engine mount. 
• Front end accessories all tight?   

[stroked67]

Thanks Wconley, I will check all that and report my findings.

[superduty]

Better check the fan. Might be ready to sling a blade.

[ericwevans]

I had a fan clutch that caused a vibration, as you turned the fan it would be easy to turn then there would be tight spots.  It has actually been going bad for a while but I never felt it because it pulverized the water pump gaskets until they started leaking, once I fixed the leak the vibration was significant.

[gdaddy01]

Don't stand over the fan while running the motor testing , blade or belt could come off and get you .

[stroked67]

I will check fan also, it's a flex fan that is riveted to hub. I work away from home all week so I check when I get back home. Thanks guys!

[120mm]

I will check fan also, it's a flex fan that is riveted to hub. I work away from home all week so I check when I get back home. Thanks guys!

I run a flex on my SBF. After reading several accounts of them grenading, the first thing I do when I get back to the US will be to take it off and replace it with OEM. Might be a good idea regardless.

[ericwevans]

I will check fan also, it's a flex fan that is riveted to hub. I work away from home all week so I check when I get back home. Thanks guys!

I run a flex on my SBF. After reading several accounts of them grenading, the first thing I do when I get back to the US will be to take it off and replace it with OEM. Might be a good idea regardless.

The new Engine Masters in MTOD came out today and they ran different mechanical fans on an engine to see which took the most horsepower to run.  I don't want to run the fun of watching it but some of the designs sapped significant horsepower.  Obviously they didn't test it, but electric is the way to go for saving horsepower.

[stroked67]

checked fan, motor mounts, tranny mount, harmonic dampner, all were tight and in right position. pulled inspection cover for torque converter, didn't see anything floating around in there, bolts were tight on TQ.  good thing I went down there though, found a little oil dripping out of an oil pan bolt, and found them all to be rattled loose to about a 1/4 turn passed hand tight! yikes! tightened them back up. fired her up, vibration was gone, Torque converter must have just been a little hot is all I can gather.  Any other points I should check?