D1 Vibration at 20 mph

[syugg]

I installed OME 751 & 762 springs and OME shocks along with the rubberized spring isolators at the top and bottom on my '96 D1 with 168K .

I'm getting a slight vibration at 20 mph and possibly at 40 mph. No vibrations at any other speeds that I noticed. I've eliminated the rotoflex at the rear driveshaft a while ago.

My front driveshaft is stock. Could it be the front driveshaft that is causing the vibration since the geometry changed as a result of the lift?

 

[ratboy]

what does the flex disc look like?

 

[p m]

Check to make sure the driveshaft joints are okay.
Also, very often, driveline vibrations go away when you coast (no acceleration and no engine braking, either) - this is one of the signs I am looking for.

 

[syugg]

what does the flex disc look like?

What is a flex disc?

Check to make sure the driveshaft joints are okay.
Also, very often, driveline vibrations go away when you coast (no acceleration and no engine braking, either) - this is one of the signs I am looking for.

When I coast the vibration is still there but not as prominent. I just greased the U-joints. How do you verify/test if the u joints are ok? In any case, I didn't have the vibration prior to the lift.

 

[p m]

"Flex disk" is rotoflex joint in the rear driveshaft. Check it for tears and cracks.

To check the driveshaft's condition, you need to take all load off it (by choking the wheels, lifting one wheel off the ground - front for front driveshaft, rear for rear, and have transfer case in neutral and e-brake off. Again, choke the wheels that are on the ground.), and shake each joint laterally (in the direction of the joint trunnions), and using both hands, check the play by twising the driveshaft parts on both sides of the joint. There should be no play at all.

 

[jrose609]

Well, after pulling both drive shafts, changing u-joints, and greasing everything, I still had the vibration. I went to see my buddy at Big-O tires. He got in my disco and drove it up on the elevator lift. As he was pulling forward, I heard the vibration. I sat down next to the rig. As Ron drove forward and back, I narrowed the noise to the exhaust. One of the exhaust hangers was barely rubbing on the rear A-arm. 10 seconds and a crow-bar and it was fixed.

Very aggravating. I spent a lot of time and money, and in the end something stupid and simple.

 

[Justin_Sherfy]

Jason,

You have a 2" lift and no vibrations? Is it OME?

 

[syugg]

"Flex disk" is rotoflex joint in the rear driveshaft. Check it for tears and cracks.

To check the driveshaft's condition, you need to take all load off it (by choking the wheels, lifting one wheel off the ground - front for front driveshaft, rear for rear, and have transfer case in neutral and e-brake off. Again, choke the wheels that are on the ground.), and shake each joint laterally (in the direction of the joint trunnions), and using both hands, check the play by twising the driveshaft parts on both sides of the joint. There should be no play at all.

The rotoflex was eliminated when I installed the driveshaft conversion kit from AB about 6 years ago.

I'll look into checking the u-joints this weekend. Thanks!

 

[jrose609]

Jason,

You have a 2" lift and no vibrations? Is it OME?

Yes. I have OME. 766 in front and 781 rear. 766 is actually a little more than 2". It's extra HD for the tdi.

I have Tom Woods front and rear