Driveshaft angle and vibrations.
Thread Starter
Racer
Joined: Apr 2014
Posts: 406
Likes: 22
From: Lyons Colorado
read this: http://www.gwb-essen.de/cataloge.html
It's more than a spacer it provides vibration isolation. This bolts to a 3/8" plate which in turn bolts to the motor. The plates form a 'v' which pushes the motor up a bunch.
It's more than a spacer it provides vibration isolation. This bolts to a 3/8" plate which in turn bolts to the motor. The plates form a 'v' which pushes the motor up a bunch.
Thread Starter
Racer
Joined: Apr 2014
Posts: 406
Likes: 22
From: Lyons Colorado
I found another article and it actually addresses the W arrangement without actually calling it that: http://www.roddingroundtable.com/tec...driveline.html
I found it a little easier to understand.
I found it a little easier to understand.
Thread Starter
Racer
Joined: Apr 2014
Posts: 406
Likes: 22
From: Lyons Colorado
Here's another:
http://www.billavista.com/Tech/Artic...ble/index.html
This one is pretty thorough, and addresses the W arrangement also. It says this:
"Most of the equipment that uses driven shafts in a broken-back configuration though, are fairly low RPM (but not all). The reason is, due to the nature (geometry) of the configuration (again, have a look at the picture above) with this setup, there's a lot more inherent strain on the slip member as it rotates. because of the opposite angles, the shaft "wobbles" the slip member back and forth as it rotates - like a skipping rope being swung. At high rpm, with anything but the tightest slip-joint assembly, this would cause a horrible vibration - that's why Spicer light duty driveshafts do not normally come factory in this arrangement. Note however, that some Land Rovers do have stock driveshafts in the broken back configuration, so it can work! I don't have any experience with these Rover's, but I imagine that the angles in the stock configuration are pretty darned small. As with the more standard single-cardan setup - start increasing the operating angles of the U-joints and the elliptical paths get more and more elliptical, the angular velocities (amount the shaft speeds up and slows down each revolution) get greater, and when you spin that shaft at 1000rpm, the more likely it is that the shaft will be noisy, harsh, and vibrate - EVEN IF the angles are matched."
Now I can do this with angles of less than 2 degrees, and may try it if I can't do something like this:
This would work well with my differential and driveshaft angles which are both essentially zero and my engine and transmission angle which is down about 2 degrees. In fact if it was longer I think it would bolt right in! I'll call my driveshaft guy today and see what he thinks.
http://www.billavista.com/Tech/Artic...ble/index.html
This one is pretty thorough, and addresses the W arrangement also. It says this:
"Most of the equipment that uses driven shafts in a broken-back configuration though, are fairly low RPM (but not all). The reason is, due to the nature (geometry) of the configuration (again, have a look at the picture above) with this setup, there's a lot more inherent strain on the slip member as it rotates. because of the opposite angles, the shaft "wobbles" the slip member back and forth as it rotates - like a skipping rope being swung. At high rpm, with anything but the tightest slip-joint assembly, this would cause a horrible vibration - that's why Spicer light duty driveshafts do not normally come factory in this arrangement. Note however, that some Land Rovers do have stock driveshafts in the broken back configuration, so it can work! I don't have any experience with these Rover's, but I imagine that the angles in the stock configuration are pretty darned small. As with the more standard single-cardan setup - start increasing the operating angles of the U-joints and the elliptical paths get more and more elliptical, the angular velocities (amount the shaft speeds up and slows down each revolution) get greater, and when you spin that shaft at 1000rpm, the more likely it is that the shaft will be noisy, harsh, and vibrate - EVEN IF the angles are matched."
Now I can do this with angles of less than 2 degrees, and may try it if I can't do something like this:
This would work well with my differential and driveshaft angles which are both essentially zero and my engine and transmission angle which is down about 2 degrees. In fact if it was longer I think it would bolt right in! I'll call my driveshaft guy today and see what he thinks.
Last edited by Illegal Vette; Sep 2, 2014 at 07:50 AM.
Drifting
Joined: Oct 2005
Posts: 1,331
Likes: 479
From: Appleton Wisconsin
I just got my Chevy High Performance magazine, they have a article on driveline angles. Tremec has a free app for the smart phones that makes your phone able to measure degrees. You use the smooth side or end of your phone to measure the degrees it really makes it easy to find out if your drive line is at the correct angles. The phone automatically compensates for switching from vertical to horizontal if everything is within the specs the three numbers are all green, if one two or all three are out of spec they will be red. I always had a high speed vibration with my Tremec TKO 600. I spent all afternoon trying different up and down angles with the engine and rear end till I was able to get all three readings green. I had to lift the trans up till the top forward metal cover was touching the tunnel, and raise the rear end up by cutting the rubber bushing so it was thinner. The higher I lifted the trans into the tunnel the easier it was to get the green readings, I have a removable support so I'm going to take the trans out and grind the metal edges down on the cover and maybe slightly modify my tunnel as needed. This app sure takes the guess work out of trying to get the angles correct.
Thread Starter
Racer
Joined: Apr 2014
Posts: 406
Likes: 22
From: Lyons Colorado
I just got my Chevy High Performance magazine, they have a article on driveline angles. Tremec has a free app for the smart phones that makes your phone able to measure degrees. You use the smooth side or end of your phone to measure the degrees it really makes it easy to find out if your drive line is at the correct angles. The phone automatically compensates for switching from vertical to horizontal if everything is within the specs the three numbers are all green, if one two or all three are out of spec they will be red. I always had a high speed vibration with my Tremec TKO 600. I spent all afternoon trying different up and down angles with the engine and rear end till I was able to get all three readings green. I had to lift the trans up till the top forward metal cover was touching the tunnel, and raise the rear end up by cutting the rubber bushing so it was thinner. The higher I lifted the trans into the tunnel the easier it was to get the green readings, I have a removable support so I'm going to take the trans out and grind the metal edges down on the cover and maybe slightly modify my tunnel as needed. This app sure takes the guess work out of trying to get the angles correct.
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Drifting
Joined: Oct 2005
Posts: 1,331
Likes: 479
From: Appleton Wisconsin
Mine was 1.6 degrees down, I had to get it to 0.03 down and the trans to 2.2 degrees down to get all the numbers green.
Thread Starter
Racer
Joined: Apr 2014
Posts: 406
Likes: 22
From: Lyons Colorado
What was your driveshaft angle?
Drifting
Joined: Oct 2005
Posts: 1,331
Likes: 479
From: Appleton Wisconsin
I wish I knew what they were thinking with the negative pinion angle, I've read that if the u-joint angles are equal it doesn't matter if they are parallel or opposite(w-configuration). My angles are equal but still the noise/vibration.
What was your driveshaft angle?
What was your driveshaft angle?
It was Up .06 degrees
Thread Starter
Racer
Joined: Apr 2014
Posts: 406
Likes: 22
From: Lyons Colorado
Thread Starter
Racer
Joined: Apr 2014
Posts: 406
Likes: 22
From: Lyons Colorado