HELP! Driveline Vibration, 6MT, 9", 2010 camaro
12-21-2015, 06:08 AM
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HELP! Driveline Vibration, 6MT, 9", 2010 camaro Please help me track down this vibration.
NA 454
RPS twin disc clutch
Stage 3 T6060 (output bearing)
1 pc aluminum driveshaft
9” fab’d housing,strange/4.22:1/35 spline wavetrac
The transmission and driveline worked perfectly for 15,000miles street and strip.
After some engine service and full fluid change, I get the car back with a vibration that started at 4000 RPM only under load. I took it to the shop that built and installed the diff and tranny. They removed the axles (these were badly worn) and driveshaft, sent them back for repair /replacement. The axles were replaced, the driveshaft rebalanced. That vibration was gone but a new one appeared. Now the vibration starts at 45 mph and gets worse to the point I don’t want to take it further (80 mph). The vibration is present regardless of gear, clutch in or out. It’s not the motor. The vibration is worse in no load coast and float. At highway speeds, it is a big enough problem I’m concerned about the impact on the driveline. It feels like the rumble strip on the edge of the highway. When turning or changing lanes at highway speeds there is no change (I believe this rules out the hubs). They replaced the driveshaft again (and turned it 180), no change. The current driveshaft has no more than .008” runout and the forward flange has zero runout. The shop doing the work still thinks it’s the driveshaft. Others I have described the issue to point to the diff. The shop doing the work, that built and installed the diff, says it’s not the diff. The axle manufacturer says it can’t be the axles, they are new.
I’ve read a rumble above 20 mph points to carrier bearings. I’ve read that a bent output shaft could do this. The output shaft exhibits no play, runout, and is true 90 deg to the axis. I suppose it could be warped in the middle, but why after all this time could that happen?
Please help with ideas. I have spent a month and 4k chasing this. The shop I’m working with still thinks it’s the driveshaft. Others still think it’s in the diff. I’ve had 3 sets of wheels on the car, no change.
Thanks for your help.
note:
The problem surfaced after the engine builder had the car for a week for engine wiring. I had them change the trans and diff fluid. I got the car back with the vibration, a loud whining coming from the diff, and 2,3,4th gear grinding when cold. I had the fluids changed again, no change.
NA 454
RPS twin disc clutch
Stage 3 T6060 (output bearing)
1 pc aluminum driveshaft
9” fab’d housing,strange/4.22:1/35 spline wavetrac
The transmission and driveline worked perfectly for 15,000miles street and strip.
After some engine service and full fluid change, I get the car back with a vibration that started at 4000 RPM only under load. I took it to the shop that built and installed the diff and tranny. They removed the axles (these were badly worn) and driveshaft, sent them back for repair /replacement. The axles were replaced, the driveshaft rebalanced. That vibration was gone but a new one appeared. Now the vibration starts at 45 mph and gets worse to the point I don’t want to take it further (80 mph). The vibration is present regardless of gear, clutch in or out. It’s not the motor. The vibration is worse in no load coast and float. At highway speeds, it is a big enough problem I’m concerned about the impact on the driveline. It feels like the rumble strip on the edge of the highway. When turning or changing lanes at highway speeds there is no change (I believe this rules out the hubs). They replaced the driveshaft again (and turned it 180), no change. The current driveshaft has no more than .008” runout and the forward flange has zero runout. The shop doing the work still thinks it’s the driveshaft. Others I have described the issue to point to the diff. The shop doing the work, that built and installed the diff, says it’s not the diff. The axle manufacturer says it can’t be the axles, they are new.
I’ve read a rumble above 20 mph points to carrier bearings. I’ve read that a bent output shaft could do this. The output shaft exhibits no play, runout, and is true 90 deg to the axis. I suppose it could be warped in the middle, but why after all this time could that happen?
Please help with ideas. I have spent a month and 4k chasing this. The shop I’m working with still thinks it’s the driveshaft. Others still think it’s in the diff. I’ve had 3 sets of wheels on the car, no change.
Thanks for your help.
note:
The problem surfaced after the engine builder had the car for a week for engine wiring. I had them change the trans and diff fluid. I got the car back with the vibration, a loud whining coming from the diff, and 2,3,4th gear grinding when cold. I had the fluids changed again, no change.
Last edited by Boulder454; 12-22-2015 at 09:10 AM.
12-22-2015, 05:39 AM
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I'd be looking into the trans, the possibility of a warped output shaft. Also inspect the splines in the driveshaft yoke.
-I read a post recently somewhere that was word for word my problem, he found a warped output shaft.
I have a MTI trans mount, the motor is on stock mounts and I have a barton short throw shifter. This combo has produced a lot of noise through the shift boot and shifter. I have not noticed any changes during this vibration. This may not mean anything but just an observation. The mechanic that has been troubleshooting this spent a lot of time at the output shaft with the DS adapter. Aft of the bearing, it's perfect, zero runout with the adapter in place. He checked runout 90 degrees to that and found nothing. So I wonder, could the shaft look good on the outside and essentially whip on the inside? Seems unlikely, but it would have the same affect as an out of balance driveshaft at that speed.
Driveshaft A is in my possession. It was fine since it's original install. I had it rebalanced just in case and the only change was an additional weight near the original. I'll pull the boot tonight and have a look at the splines. Driveshaft B is brand new, on the car, and made no change to the situation. Both are 3.5" aluminum, both have the weight tig welded on.
ssvert99, my family is in Bloomington, I was planning on coming up there. Would you have time to investigate this during the next 2 weeks? I really won't need the car until January 3rd.
Thank you both for the tips, This is driving me insane and I can't race the car until the issue is resolved.
I'm in North Carolina. If anyone knows a driveline expert, please give me a referral. Thank you
-I read a post recently somewhere that was word for word my problem, he found a warped output shaft.
I have a MTI trans mount, the motor is on stock mounts and I have a barton short throw shifter. This combo has produced a lot of noise through the shift boot and shifter. I have not noticed any changes during this vibration. This may not mean anything but just an observation. The mechanic that has been troubleshooting this spent a lot of time at the output shaft with the DS adapter. Aft of the bearing, it's perfect, zero runout with the adapter in place. He checked runout 90 degrees to that and found nothing. So I wonder, could the shaft look good on the outside and essentially whip on the inside? Seems unlikely, but it would have the same affect as an out of balance driveshaft at that speed.
Driveshaft A is in my possession. It was fine since it's original install. I had it rebalanced just in case and the only change was an additional weight near the original. I'll pull the boot tonight and have a look at the splines. Driveshaft B is brand new, on the car, and made no change to the situation. Both are 3.5" aluminum, both have the weight tig welded on.
ssvert99, my family is in Bloomington, I was planning on coming up there. Would you have time to investigate this during the next 2 weeks? I really won't need the car until January 3rd.
Thank you both for the tips, This is driving me insane and I can't race the car until the issue is resolved.
I'm in North Carolina. If anyone knows a driveline expert, please give me a referral. Thank you
Last edited by Boulder454; 12-22-2015 at 07:14 AM.
12-25-2015, 10:25 AM
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Curious, is the three wheels aftermarket? Try running stock wheels on all four's. I've have aftermarket wheels and had to use hubcentric rings and they still vibrated at speeds over 40 mph. Just my opinion.
12-25-2015, 10:33 AM
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Please help me track down this vibration.
NA 454
RPS twin disc clutch
Stage 3 T6060 (output bearing)
1 pc aluminum driveshaft
9” fab’d housing,strange/4.22:1/35 spline wavetrac
The transmission and driveline worked perfectly for 15,000miles street and strip.
After some engine service and full fluid change, I get the car back with a vibration that started at 4000 RPM only under load. I took it to the shop that built and installed the diff and tranny. They removed the axles (these were badly worn) and driveshaft, sent them back for repair /replacement. The axles were replaced, the driveshaft rebalanced. That vibration was gone but a new one appeared. Now the vibration starts at 45 mph and gets worse to the point I don’t want to take it further (80 mph). The vibration is present regardless of gear, clutch in or out. It’s not the motor. The vibration is worse in no load coast and float. At highway speeds, it is a big enough problem I’m concerned about the impact on the driveline. It feels like the rumble strip on the edge of the highway. When turning or changing lanes at highway speeds there is no change (I believe this rules out the hubs). They replaced the driveshaft again (and turned it 180), no change. The current driveshaft has no more than .008” runout and the forward flange has zero runout. The shop doing the work still thinks it’s the driveshaft. Others I have described the issue to point to the diff. The shop doing the work, that built and installed the diff, says it’s not the diff. The axle manufacturer says it can’t be the axles, they are new.
I’ve read a rumble above 20 mph points to carrier bearings. I’ve read that a bent output shaft could do this. The output shaft exhibits no play, runout, and is true 90 deg to the axis. I suppose it could be warped in the middle, but why after all this time could that happen?
Please help with ideas. I have spent a month and 4k chasing this. The shop I’m working with still thinks it’s the driveshaft. Others still think it’s in the diff. I’ve had 3 sets of wheels on the car, no change.
Thanks for your help.
note:
The problem surfaced after the engine builder had the car for a week for engine wiring. I had them change the trans and diff fluid. I got the car back with the vibration, a loud whining coming from the diff, and 2,3,4th gear grinding when cold. I had the fluids changed again, no change.
NA 454
RPS twin disc clutch
Stage 3 T6060 (output bearing)
1 pc aluminum driveshaft
9” fab’d housing,strange/4.22:1/35 spline wavetrac
The transmission and driveline worked perfectly for 15,000miles street and strip.
After some engine service and full fluid change, I get the car back with a vibration that started at 4000 RPM only under load. I took it to the shop that built and installed the diff and tranny. They removed the axles (these were badly worn) and driveshaft, sent them back for repair /replacement. The axles were replaced, the driveshaft rebalanced. That vibration was gone but a new one appeared. Now the vibration starts at 45 mph and gets worse to the point I don’t want to take it further (80 mph). The vibration is present regardless of gear, clutch in or out. It’s not the motor. The vibration is worse in no load coast and float. At highway speeds, it is a big enough problem I’m concerned about the impact on the driveline. It feels like the rumble strip on the edge of the highway. When turning or changing lanes at highway speeds there is no change (I believe this rules out the hubs). They replaced the driveshaft again (and turned it 180), no change. The current driveshaft has no more than .008” runout and the forward flange has zero runout. The shop doing the work still thinks it’s the driveshaft. Others I have described the issue to point to the diff. The shop doing the work, that built and installed the diff, says it’s not the diff. The axle manufacturer says it can’t be the axles, they are new.
I’ve read a rumble above 20 mph points to carrier bearings. I’ve read that a bent output shaft could do this. The output shaft exhibits no play, runout, and is true 90 deg to the axis. I suppose it could be warped in the middle, but why after all this time could that happen?
Please help with ideas. I have spent a month and 4k chasing this. The shop I’m working with still thinks it’s the driveshaft. Others still think it’s in the diff. I’ve had 3 sets of wheels on the car, no change.
Thanks for your help.
note:
The problem surfaced after the engine builder had the car for a week for engine wiring. I had them change the trans and diff fluid. I got the car back with the vibration, a loud whining coming from the diff, and 2,3,4th gear grinding when cold. I had the fluids changed again, no change.
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01-12-2016, 09:38 AM
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Data Point:
I worked with a GM tech this morning.
He hooked up a
Kent-Moore J38792 EVA.
At highway speeds I disengaged the clutch and got the following output:
45-65 mph = Prop 1 vibration - 45-80 Hz
75-95 mph = 220-250 HZ
He said the unit would only take 4.10 gear input, I have a 4.22:1
His assessment is I have a driveline angle issue.
This has been a theory of many, but that angle has not changed over the life of the 9" install. (everything was fine after the original install)
I will find a way to get the exact angle shortly.
I worked with a GM tech this morning.
He hooked up a
Kent-Moore J38792 EVA.
At highway speeds I disengaged the clutch and got the following output:
45-65 mph = Prop 1 vibration - 45-80 Hz
75-95 mph = 220-250 HZ
He said the unit would only take 4.10 gear input, I have a 4.22:1
His assessment is I have a driveline angle issue.
This has been a theory of many, but that angle has not changed over the life of the 9" install. (everything was fine after the original install)
I will find a way to get the exact angle shortly.
