Bad vibration

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Dana

Dana

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FABO Vendor
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I've got an 833 o/d in my swinger. In first and second especially during acceleration there little if any vibration. Third it gets worse on deceleration. Fourth gear it vibrates on acceleration and in coast it is in undrivable. Pushing the clutch in makes it a little better. Has anyone experienced this. Any thoughts or ideas would be greatly appreciated. I pulled it today, so its out of the car. Thanks
 
Robbie2734 said:
Bad universals or drive shaft out of balance.
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Brand new Moog u joints. I just had this driveshaft made. I told him I wanted it balanced. He said it is a seamless shaft and they are very true. He would be more than happy to send it out to balance, but he was confident I'd be happy without balancing. It's not like he's a shoe. Mark Williams bought him out years ago, now he just does side work.
 
I'll check it. What should it be 1.5 -2 degrees?
 
Make sure rear U-joint is using the clips, they are on the inside of the yoke. without them it wont be centered.
 
Dana said:
I'll check it. What should it be 1.5 -2 degrees?
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The nose of the pinion should be the same number as the transmission axis but in the opposite direction. So if the pinion is pointing down at 2 degrees, the trans axis at the tail should be up 2 degrees. Therefore they will remain parallel.
 
I'll bet you a dollar, your clutch hub threw a spring. My 360 used to eat 340 discs. It always blew the hub. Sometimes a spring or a piece of lining would take off and get mangled up in there. I finally left the cover off, so that stuff could get away. Solved the lining issue, but the spring is always trapped.
 
68gtxman said:
The nose of the pinion should be the same number as the transmission axis but in the opposite direction. So if the pinion is pointing down at 2 degrees, the trans axis at the tail should be up 2 degrees. Therefore they will remain parallel.
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This might work for a low-powered cruiser.
But if you start to put power through it, set up like that,and most especially with non-SS springs, the pinion will wrap up to the wrong side, from 2 to 5 or more degrees, depending on several factors.So for small blocks you can figure on adding about 1 degree per fifty horsepower,over 250, and a minimum of tranny plus 1 degree down. So a stock teener would be a minimum of tranny plus 1, and a 400 hp 360 might be tranny plus 3.This will get you a good starting point for non-SS springs. Shims are available.The pinion must always be nose down.Cuz, you know, it climbs up under pressure.
 
So he didnt balance the driveshaft...perhaps an output shaft bushing?
I was also going to mention the pinion offset. It should not be "0" it should be slightly under 0 so when you wrap up the rear, it becomes 0. Nose down a few degrees depending on your setup.
 
pishta said:
So he didnt balance the driveshaft...perhaps an output shaft bushing?
I was also going to mention the pinion offset. It should not be "0" it should be slightly under 0 so when you wrap up the rear, it becomes 0. Nose down a few degrees depending on your setup.
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I agree, but I didn't want to get into a greatly detailed explanation when the man should be reviewing his service manual when the problem starts getting complex.
 
I would have the driveshaft checked. Possible its in the transmission, but the driveshaft is the easiest place to start.
 
Dana said:
I've got an 833 o/d in my swinger. In first and second especially during acceleration there little if any vibration. Third it gets worse on deceleration. Fourth gear it vibrates on acceleration and in coast it is in undrivable. Pushing the clutch in makes it a little better. Has anyone experienced this. Any thoughts or ideas would be greatly appreciated. I pulled it today, so its out of the car. Thanks
Click to expand...

Well you might want to check your rear springs and axle U-bolts then.Cuz in 3rd and 4th gear, under coast, the pinion is yanked down by compression braking. If the u-bolts are loose or a spring is broken, voila.The pinion angle would go extreme.
 
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