Driveline/Pinion Angle and Vibration HELP
09-02-2009, 09:02 PM
#61
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going through the same thing vibes at 45-60 then again at 130. I have several issues to fix yet to see if it helps but could this possibly be a pinion problem. maybe the bearing going out?
09-02-2009, 09:35 PM
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I thought that to be a good reason that its happening, but it keeps tearing up the tailshaft bushing in the trans, so it is definitely a driveshaft/angle problem.
09-03-2009, 02:47 PM
#66
If you could full isolate the torque arm mount from the body using rubber it might help. Not sure you can do this because whatever you make will reduce ground clearance plus it would have to be able to withstand massive torque loads.
09-03-2009, 06:54 PM
#67
Where the bolts tightens in the "nut" end of the fastener will form a rigid metal point for vibration to be transmitted. This will be 4X. Wont help a bit.
If you could full isolate the torque arm mount from the body using rubber it might help. Not sure you can do this because whatever you make will reduce ground clearance plus it would have to be able to withstand massive torque loads.
If you could full isolate the torque arm mount from the body using rubber it might help. Not sure you can do this because whatever you make will reduce ground clearance plus it would have to be able to withstand massive torque loads.
09-03-2009, 08:25 PM
#68
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I have done some searching for driveline shops out here in southern california but didn't really find anything. I will look around for a chassis place, hopefully I can drop my car of and say "it vibrates, PLEASE fix it" and it wont be too expensive haha.
09-04-2009, 02:41 PM
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Alrighty update time from me. FIXED
We got the new aluminum DS from PST in earlier this week. Installed the drive shaft and a 1/8" thick piece of rubber under the torque arm mount. Im sure the rubber isnt doing much but the vibration is gone. So anyone having these issues and adjusting the pinon angle isnt helping, you might look into who built your DS and what its made of. I had a chromemoly DS from strange installed and the aluminum one from PST fixed all vibration problems I was having.
Any for anyone else having problems I would use this check list.
DS - material, has it been balanced? ( my chromoly one was balanced to a very high rpm and was still the problem )
Pinion angle- check it and check it again
Rear ride height- is your pinon angle off cause of how low you are?
Ride height isnt going to play a huge roll in your setup unless you can not get your pinon angle correct due to it.
We got the new aluminum DS from PST in earlier this week. Installed the drive shaft and a 1/8" thick piece of rubber under the torque arm mount. Im sure the rubber isnt doing much but the vibration is gone. So anyone having these issues and adjusting the pinon angle isnt helping, you might look into who built your DS and what its made of. I had a chromemoly DS from strange installed and the aluminum one from PST fixed all vibration problems I was having.
Any for anyone else having problems I would use this check list.
DS - material, has it been balanced? ( my chromoly one was balanced to a very high rpm and was still the problem )
Pinion angle- check it and check it again
Rear ride height- is your pinon angle off cause of how low you are?
Ride height isnt going to play a huge roll in your setup unless you can not get your pinon angle correct due to it.
09-04-2009, 03:37 PM
#70
Alrighty update time from me. FIXED
We got the new aluminum DS from PST in earlier this week. Installed the drive shaft and a 1/8" thick piece of rubber under the torque arm mount. Im sure the rubber isnt doing much but the vibration is gone. So anyone having these issues and adjusting the pinon angle isnt helping, you might look into who built your DS and what its made of. I had a chromemoly DS from strange installed and the aluminum one from PST fixed all vibration problems I was having.
Any for anyone else having problems I would use this check list.
DS - material, has it been balanced? ( my chromoly one was balanced to a very high rpm and was still the problem )
Pinion angle- check it and check it again
Rear ride height- is your pinon angle off cause of how low you are?
Ride height isnt going to play a huge roll in your setup unless you can not get your pinon angle correct due to it.
We got the new aluminum DS from PST in earlier this week. Installed the drive shaft and a 1/8" thick piece of rubber under the torque arm mount. Im sure the rubber isnt doing much but the vibration is gone. So anyone having these issues and adjusting the pinon angle isnt helping, you might look into who built your DS and what its made of. I had a chromemoly DS from strange installed and the aluminum one from PST fixed all vibration problems I was having.
Any for anyone else having problems I would use this check list.
DS - material, has it been balanced? ( my chromoly one was balanced to a very high rpm and was still the problem )
Pinion angle- check it and check it again
Rear ride height- is your pinon angle off cause of how low you are?
Ride height isnt going to play a huge roll in your setup unless you can not get your pinon angle correct due to it.
09-04-2009, 04:43 PM
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One thing to note for people with the torque arm from midwest. The 1st batch he put out the torque arms were about 1/4 inch too long. This will cause some rattle noises inside the car when the rear end torques forward. Basically the mounting point for the torque arm is on a swivel style bracket attached to the mounting brace. When the rear torques towards the front of the car the bracket ( that the torque arm attaches to ) will swivel forward and touch the brace itself ( the location is on the verticle support piece that holds the drive shaft saftey loop ). Not sure if anyone else out there is having this issue but we just found this out on my car. The only solution we have is to cut the toque arm itself about 1/4 back and re-tapping the threads. Also we will be looking into modifying the attaching bracket to see if it can be shortened to not hit the brace.
09-04-2009, 04:58 PM
#72
No i did not. While the old drive shaft was out I went ahead and did both things, so I have no proof that the rubber did anything at all or was the thing that fixed the car. The rubber i bought from mc mastercarr # 2983k22.
One thing to note for people with the torque arm from midwest. The 1st batch he put out the torque arms were about 1/4 inch too long. This will cause some rattle noises inside the car when the rear end torques forward. Basically the mounting point for the torque arm is on a swivel style bracket attached to the mounting brace. When the rear torques towards the front of the car the bracket ( that the torque arm attaches to ) will swivel forward and touch the brace itself ( the location is on the verticle support piece that holds the drive shaft saftey loop ). Not sure if anyone else out there is having this issue but we just found this out on my car. The only solution we have is to cut the toque arm itself about 1/4 back and re-tapping the threads. Also we will be looking into modifying the attaching bracket to see if it can be shortened to not hit the brace.
One thing to note for people with the torque arm from midwest. The 1st batch he put out the torque arms were about 1/4 inch too long. This will cause some rattle noises inside the car when the rear end torques forward. Basically the mounting point for the torque arm is on a swivel style bracket attached to the mounting brace. When the rear torques towards the front of the car the bracket ( that the torque arm attaches to ) will swivel forward and touch the brace itself ( the location is on the verticle support piece that holds the drive shaft saftey loop ). Not sure if anyone else out there is having this issue but we just found this out on my car. The only solution we have is to cut the toque arm itself about 1/4 back and re-tapping the threads. Also we will be looking into modifying the attaching bracket to see if it can be shortened to not hit the brace.
09-05-2009, 06:35 PM
#73
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Alrighty update time from me. FIXED
We got the new aluminum DS from PST in earlier this week. Installed the drive shaft and a 1/8" thick piece of rubber under the torque arm mount. Im sure the rubber isnt doing much but the vibration is gone. So anyone having these issues and adjusting the pinon angle isnt helping, you might look into who built your DS and what its made of. I had a chromemoly DS from strange installed and the aluminum one from PST fixed all vibration problems I was having.
Any for anyone else having problems I would use this check list.
DS - material, has it been balanced? ( my chromoly one was balanced to a very high rpm and was still the problem )
Pinion angle- check it and check it again
Rear ride height- is your pinon angle off cause of how low you are?
Ride height isnt going to play a huge roll in your setup unless you can not get your pinon angle correct due to it.
We got the new aluminum DS from PST in earlier this week. Installed the drive shaft and a 1/8" thick piece of rubber under the torque arm mount. Im sure the rubber isnt doing much but the vibration is gone. So anyone having these issues and adjusting the pinon angle isnt helping, you might look into who built your DS and what its made of. I had a chromemoly DS from strange installed and the aluminum one from PST fixed all vibration problems I was having.
Any for anyone else having problems I would use this check list.
DS - material, has it been balanced? ( my chromoly one was balanced to a very high rpm and was still the problem )
Pinion angle- check it and check it again
Rear ride height- is your pinon angle off cause of how low you are?
Ride height isnt going to play a huge roll in your setup unless you can not get your pinon angle correct due to it.
09-08-2009, 06:20 PM
#74
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I dont see how changing a driveshaft would change any angles at all. Mine disappeared randomly after pulling the rear axle out to have it check, but came back again when I pulled the trans and torque arm a few months later to change the slave cylinder.
09-09-2009, 04:23 PM
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Yes the angles changed due to the fact that I placed a 1/8 thick piece of rubber under the torque arm mounting bracket. The angles were adjusted back to what they were before ( they didnt change much 1/2 a degree ish ).
I can give a small update on the car since I just went on a cruise to vegas
Took the car up to 130mph ish and not a single vibration. The torque arm is still rubbing the vertical brace for the saftey loop though. Not sure what the next step is on this but I found out I received one of the 1st torque arms from Midwest which were supposed to be about 1/4-3/8 inch too long. We trimmed off and cleaned up the threads.. same issue. It did seem to lessen the frequency between when the torque arm hits but still hits non-the-less.
I was getting 2 sets of vibrations in my car. Around 70mph the car had a small livable vibration that went away when I hit say 75mph. Then once I reached 105 MPH the vibration came back and was tooth rattling.
So yeah 1st thing as always is check your angles. If your angles are looking good its a good chance that your DS might be the reason. Be careful about just getting it balanced too. My old one was balanced up to over 8k RPM and still had the problem. PST makes a killer DS, and I think that Eric at Midwest is looking at going with them from now on instead of Strange.
I can give a small update on the car since I just went on a cruise to vegas
Took the car up to 130mph ish and not a single vibration. The torque arm is still rubbing the vertical brace for the saftey loop though. Not sure what the next step is on this but I found out I received one of the 1st torque arms from Midwest which were supposed to be about 1/4-3/8 inch too long. We trimmed off and cleaned up the threads.. same issue. It did seem to lessen the frequency between when the torque arm hits but still hits non-the-less.I was getting 2 sets of vibrations in my car. Around 70mph the car had a small livable vibration that went away when I hit say 75mph. Then once I reached 105 MPH the vibration came back and was tooth rattling.
So yeah 1st thing as always is check your angles. If your angles are looking good its a good chance that your DS might be the reason. Be careful about just getting it balanced too. My old one was balanced up to over 8k RPM and still had the problem. PST makes a killer DS, and I think that Eric at Midwest is looking at going with them from now on instead of Strange.
10-03-2009, 04:28 PM
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took my car to a driveline shop. had a bent shaft. they replaced it but the problem was still there. it looks like it may have something to do with the converter lockup as the problem only starts in OD beginning at 2K rpm and around 45 mph.