Last time I went to the track I picked up a vibration on the big end. I believe that it is rpm induced but not 100% sure I basically babied the car home. I havent had a chance to really check it out. Could the balancer cause it. Its not wobbling and the timing seems to be close to what I set it. Maybe off a couple degrees from what I thought I set it to. I missed a shift in my G Force T5 went 3rd to 2nd instead of 4th and I am hoping that its not the transmission. What you guys think?

 

Use to sell alot of harmonic balancers for the 5.0's, could have spun it on the downshift? Check TDC and see f it moved.

 

If it's a stock balancer, it's suspect. If not, then could be something else. You should be able to tell if it's RPM related sitting in your driveway. Just rev it up to the vibration range with the clutch in. Then again with the clutch out. If it's worse clutch out, then it might be the input shaft....

 

Going to mess with it here in a bit.

 

Ok I am pretty sure its not the trans at all. Its between 3-4000 rpms and I feel it way worse on decel. Its pretty bad at 6200+. Timing is dead on what i set it at, and the balancer has a tiny wobble but not more then an 1/8 inch. If the weight fell off the flywheel it would be way worse wouldnt it? I was thinking maybe bad motor mount. Thats probably what I will look into next.

 

Well, while the mounts do need to be in place, they won't cause a vibration that alarms you generally. Did you test it while stopped? High RPM vibrate like crazy?

 

I notice it worse while in it hard in 4th, but I think its cause its in that RPM range for a while and on decel its way pretty bad. I feel it through the shifter. But I think its just cause there is pressure on everything. It does it sitting still, clutch in, clutch out. As long as it isnt in that RPM range its smooth, and the car is still running very well. Shoot the pass it started doing it was my best ET to date. I may just buy one of those 150 dollar Summit SFI balancers and see it that fixes it. I should probably replace it anyways with the RPMs the car sees.

 

I think it's cheap piece of mind. And while you're in there you can look at the mounts to see if you have to stock style V8 mounts (one piece) or the later two piece style (convertible) mounts.

 

I am guessing they are the stock style since it only has 50,000 miles on it. Are the convertible style better?

 

Yes. They are a "captured" design. Meaning you can't rip them in two like the normal 5.0 mount that is just a huge hunk of rubber.

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OK thanks for the help btw.

 

New balancer on and its still there. But now its different. It doesnt seem rpm based anymore. I dont know what the heck is going on. Before it was dead on the rpms when it would start and stop. Now its just whenever. And it does it moving more. I am confused, I am just going to pull the driveshaft and check u-joints. If they look fine I guess the transmission is coming out.... Yippy

 

does it do it with the clutch down and the trans in gear?

 

The old vibration it would do it sitting still clutch in or out and transmission in gear or out. This new one does it coasting @ 70 clutch in or out trans out of gear and engine off. This new vibration is different though. Feels like a driveshaft now.

 

Does it do it at all sitting still?

 

It did before this new vibration but forgot to check. I am going to pull the transmission and drive shaft. I have got to figure this out.

 

If it is doing it when you are not moving that rules out the driveshaft. I would pull the trans and inspect the flywheel, pressure plate, and clutch disk carefully. I have broke shit on the very first launch on sticky tires.

 

Yeah I thought the clutch too but I pushed the clutch in, pulled it out of gear and shut the engine off at 70mph. Still there. Very strange vibration. I have a feeling I hurt the transmission in some way if not I dont know whats going on unless there is 2 different vibrations which is possible.

 

Thank god I am just a dumb ass.... Should have checked the drive shaft. Damn bolts backed out. I pulled the shaft checked u joints and for straightness and all was good so I stuck it back in. Took it for a drive and all is well! I figured it would be something stupid. I am pretty sure the balancer was off a little bit too because the motor seems smoother now. Plus I should have an SFI rated one with how I rev it. Now I can spent the saved money on fun stuff instead of fixing broke stuff!

 

Been there , after my surgery I couldn't get under the car so a buddy put my drive shaft back in and got a call in the middle of it and forgot to go back and torque them down and they backed out , Depending on how much you drove it like that it could have beat the pinion nose bearing up.