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Dually Engine \ Vibration between 25-30 mphVibration between 25-30 mph
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replies 22
following 9
someotherguy
+1y
That joint might be toast from bad driveline angle so I wouldn't write off that research just yet.
Richard
Richard
dzl1
+1y
Ok so going by your previous post, you did 3 degrees for both front and rear. My question is how would you go about measuring that? Also is 3 degrees the correct angle? Thanks for all your help.
DZL1.
DZL1.
someotherguy
+1y
I'll tell you right up front I'm no expert on this subject, I know enough to be dangerous I guess it's a subject that should be simple but if you do some reading around the net you will find dozens of different opinions on how it should be set up, how it should be measured, blah blah. My suggestion would be to do some googling on it and try to form a concensus from some of the info.
Just remember that correct angle will vary depending on application - leaf sprung rears wrap up under acceleration way more than somebody who's 4 linked, so leafs need more angle. A lot of the driveline angle discussions out there are aimed at racers so if you're reading an article that doesn't elaborate which setup they're discussing maybe move on to another with better info.
Not trying to cop-out on the answer but some of the intricacies of it are over my head and I don't want to give you bad info, mostly just trying to warn you that if you're experiencing vibration and busted U-joints, the U-joint may have broken because of bad driveline angle (not enough, in the case of most lowered vehicles).
Richard
Just remember that correct angle will vary depending on application - leaf sprung rears wrap up under acceleration way more than somebody who's 4 linked, so leafs need more angle. A lot of the driveline angle discussions out there are aimed at racers so if you're reading an article that doesn't elaborate which setup they're discussing maybe move on to another with better info.
Not trying to cop-out on the answer but some of the intricacies of it are over my head and I don't want to give you bad info, mostly just trying to warn you that if you're experiencing vibration and busted U-joints, the U-joint may have broken because of bad driveline angle (not enough, in the case of most lowered vehicles).
Richard
dzl1
+1y
Ok thanks for making me aware of this possibility. I will research this. I appreciate your time amd help.
DZL1.
DZL1.
someotherguy
+1y
No prob...wish I could explain it more eloquently but I've already told you everything I know on the subject.
When I bought my '92 ext cab longbed it had a horrible vibration at lower speeds, I mean it buzzed the whole damn truck, was nearly undrivable. I thought it might have been driveline angle but the more I looked into it I started to wonder if the driveshafts needed to be balanced, if weights had been knocked off dragging it over driveway peaks or something. Didn't even notice until the shaft was off the truck that whoever had replaced the u-joints before I bought it, hadn't driven them all the way in, and left the clips out so the bearing caps were walking out of the f'ing yokes. This is the same truck that almost popped a ball joint loose because the asshats didn't put a cotter pin through the nut (had a castle nut, not a jam nut style.) Only reason I even caught it was I went in to grind a tiny bit of casting flash off the brake caliper because it was rubbing on the inside hoop of the 15" wheels I ran when I first put it on the road.
Richard
When I bought my '92 ext cab longbed it had a horrible vibration at lower speeds, I mean it buzzed the whole damn truck, was nearly undrivable. I thought it might have been driveline angle but the more I looked into it I started to wonder if the driveshafts needed to be balanced, if weights had been knocked off dragging it over driveway peaks or something. Didn't even notice until the shaft was off the truck that whoever had replaced the u-joints before I bought it, hadn't driven them all the way in, and left the clips out so the bearing caps were walking out of the f'ing yokes. This is the same truck that almost popped a ball joint loose because the asshats didn't put a cotter pin through the nut (had a castle nut, not a jam nut style.) Only reason I even caught it was I went in to grind a tiny bit of casting flash off the brake caliper because it was rubbing on the inside hoop of the 15" wheels I ran when I first put it on the road.
Richard
rushnbobo
+1y
Measure your driveshaft with a angle finder.....you can pic up a decent one under 20 bucks.
Make sure that two opposing u-joint cups are as close as possible to plumb....lay the tool on the driveshaft take note of angle on guage. Now without moving anything, take a socket that will barely fit inside the yoke on one of the bearing cups, either top or bottom, doesn't matter (this gives you a decent surface to lay the angle finder on) and hold the angle finder on this socket. Observe measurement and compare with first.....this is your angle.
I agree with Richard.....about 3 degrees is ideal but there is room for a slight discrepancy in the two angles without noticeable problems with vibration.......while the amount of angle is important, the angles being as close as possible to each other even more critical. Some raised or lowered rides do not wind up with exact angles front and rear, but they do need to be very close. Just as important you never want "zero angle" in a u-joint....the needle bearings are meant to roll back and forth as the shaft rotates, without this rotatation in the bearings they will "flat spot" in short order and self destruct.
Measure your driveshaft with a angle finder.....you can pic up a decent one under 20 bucks.
Make sure that two opposing u-joint cups are as close as possible to plumb....lay the tool on the driveshaft take note of angle on guage. Now without moving anything, take a socket that will barely fit inside the yoke on one of the bearing cups, either top or bottom, doesn't matter (this gives you a decent surface to lay the angle finder on) and hold the angle finder on this socket. Observe measurement and compare with first.....this is your angle.
I agree with Richard.....about 3 degrees is ideal but there is room for a slight discrepancy in the two angles without noticeable problems with vibration.......while the amount of angle is important, the angles being as close as possible to each other even more critical. Some raised or lowered rides do not wind up with exact angles front and rear, but they do need to be very close. Just as important you never want "zero angle" in a u-joint....the needle bearings are meant to roll back and forth as the shaft rotates, without this rotatation in the bearings they will "flat spot" in short order and self destruct.
dzl1
+1y
Richard, again thanks for your help.
Rushnbobo, thanks for the description and pic as to how to tell driveline angles.
Guys thanks for all your help, it is Greatly Appreciated! Hopefully I will be able to return the favor one day.
DZL1.
Rushnbobo, thanks for the description and pic as to how to tell driveline angles.
Guys thanks for all your help, it is Greatly Appreciated! Hopefully I will be able to return the favor one day.
DZL1.