Vibration
#1
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Vibration
OK, I have been chasing a vibration for a year or so now. I just replaced the driveshaft and still have the vibration. It goes with the car speed and is independent of engine speed or gear selection or clutch engagement. It is pretty high frequency which leads me to believe it is not the wheels/tires or axles. Over the weekend I will try and get the car up and remove the driveshaft to watch the output shaft for out of round. It feels like it is coming from behind the front seats and under the car. Feels center of the car, not left or right. Any suggestions? I do not have the money to just take it to a shop. The rear has new gears and "rebuild" on it. No telling what parts were replaced when the gear was swapped. Experience tells me it is not a bearing since I would hear it all the time. I get the vibration at about 70+ most prominently.
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Ever changed gears or ran your car on good tires at the track? It's easy to throw the pinion angle off on these cars and basically an adjustable torque arm is the only way to get rid of it.
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I do not get it in the steering. I have a fixed TA so angle can not be changed manually or mistakenly. It would have to actually be bent. I do have adjustable LCAs and think that one may be shorter than the other. I will try making them even. Also, I have two other sets of rear wheels/tires. I will try swapping out a pair and see if that helps, but I really don't think it is that.
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I don't see how you can throw off pinion angle on a fixed angle TA. I have a chassi mounted TA/trans mount too so I am not flexing the mount or anything. I could check it anhow. Just need a tool to do so.
#11
I do not get it in the steering. I have a fixed TA so angle can not be changed manually or mistakenly. It would have to actually be bent. I do have adjustable LCAs and think that one may be shorter than the other. I will try making them even. Also, I have two other sets of rear wheels/tires. I will try swapping out a pair and see if that helps, but I really don't think it is that.
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I pulled the shaft out and watched the output shaft on the trans. Seams true by the eye. My output shaft bushing is new. Driveshaft is new and ballanced.
I swapped the rear wheels/tires to see if that makes a difference (bent or unballanced wheel) but have not had a chance to drive it yet.
I did have oil coming out of the pinion yoke where the nut holds it on. Very strange. Never seen that before. So I tried to tighten that best I could. Will have to see if that stops leaking now.
I have a Detroit locker. Seams to work fine but this is the first and only locker I have driven.
Only other thing I can think of is a bent axle. Not sure how that would have hapenned though. I ran the car with the wheels on and off and I could see the right rear rotor was turning out of round but not sure if that is the rotor or the axle hub. What is the tolerance of an axle hub or rotor out of round? Obviously if the axle hub is out of round it will be amplified by the rotor and then wheel.
I swapped the rear wheels/tires to see if that makes a difference (bent or unballanced wheel) but have not had a chance to drive it yet.
I did have oil coming out of the pinion yoke where the nut holds it on. Very strange. Never seen that before. So I tried to tighten that best I could. Will have to see if that stops leaking now.
I have a Detroit locker. Seams to work fine but this is the first and only locker I have driven.
Only other thing I can think of is a bent axle. Not sure how that would have hapenned though. I ran the car with the wheels on and off and I could see the right rear rotor was turning out of round but not sure if that is the rotor or the axle hub. What is the tolerance of an axle hub or rotor out of round? Obviously if the axle hub is out of round it will be amplified by the rotor and then wheel.
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I pulled the shaft out and watched the output shaft on the trans. Seams true by the eye. My output shaft bushing is new. Driveshaft is new and ballanced.
I swapped the rear wheels/tires to see if that makes a difference (bent or unballanced wheel) but have not had a chance to drive it yet.
I did have oil coming out of the pinion yoke where the nut holds it on. Very strange. Never seen that before. So I tried to tighten that best I could. Will have to see if that stops leaking now.
I have a Detroit locker. Seams to work fine but this is the first and only locker I have driven.
Only other thing I can think of is a bent axle. Not sure how that would have hapenned though. I ran the car with the wheels on and off and I could see the right rear rotor was turning out of round but not sure if that is the rotor or the axle hub. What is the tolerance of an axle hub or rotor out of round? Obviously if the axle hub is out of round it will be amplified by the rotor and then wheel.
I swapped the rear wheels/tires to see if that makes a difference (bent or unballanced wheel) but have not had a chance to drive it yet.
I did have oil coming out of the pinion yoke where the nut holds it on. Very strange. Never seen that before. So I tried to tighten that best I could. Will have to see if that stops leaking now.
I have a Detroit locker. Seams to work fine but this is the first and only locker I have driven.
Only other thing I can think of is a bent axle. Not sure how that would have hapenned though. I ran the car with the wheels on and off and I could see the right rear rotor was turning out of round but not sure if that is the rotor or the axle hub. What is the tolerance of an axle hub or rotor out of round? Obviously if the axle hub is out of round it will be amplified by the rotor and then wheel.
see my post above
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Oh, I forgot to mention that my control arms are indeed even in length.
Torchd, I will try and get an angle finder on it and see where it is at. I can udjust my front mount to change the angle, but I can only go steeper (less parallel with the car). Where should it be? 2.5* I think.
Torchd, I will try and get an angle finder on it and see where it is at. I can udjust my front mount to change the angle, but I can only go steeper (less parallel with the car). Where should it be? 2.5* I think.
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Oh, I forgot to mention that my control arms are indeed even in length.
Torchd, I will try and get an angle finder on it and see where it is at. I can udjust my front mount to change the angle, but I can only go steeper (less parallel with the car). Where should it be? 2.5* I think.
Torchd, I will try and get an angle finder on it and see where it is at. I can udjust my front mount to change the angle, but I can only go steeper (less parallel with the car). Where should it be? 2.5* I think.
usually you want the it to be at -1* or -2*
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OK. I ran the car on stands and did see a wable in the wheel/tire on the pass side. I removed the wheel, bolted down the rotor and ran it again. There is a wable in the rotor. So now I am not sure if it is the rotor or the axle. Does that mean I may have found it though? No idea if this could cause the fibration I am having. I have new rotors and will put them on and see what that looks like. If it continues, then I obviously have a bent axle.