Crazy driveline vibration after AR5 conversion
I am in need of help figuring out a crazy driveline vibration I am having after doing an AR5 transmission conversion.
It gets noticeable after about 40mph, and starts to violently shake the whole car after about 50. It gradually worsens as speed increases, and does not fade away after a certain speed.
Tires are not the issue. When the rear wheels are lifted off the ground and I run the car through the gears, the vibration heavily resonates through the whole car as if I had subwoofers in the trunk and was doing a frequency test.
The engine and the rear end were not touched, other than clutch and flywheel. Only the driveshaft and the transmission were changed. The transmission itself has about 80k miles, and shifts beautifully. I do not believe it to be the issue.
I am using a 1 piece driveshaft that bolts directly to the differential flange, and bolts to the transmission using the Driftmotion 6 to 4 bolt adapter. I had the outer diameter of the adaptor machined down by a driveshaft shop to eliminate any clearance issues with the JZX110 shifter housing.
I have checked every location where the driveshaft could possibly come close to contacting anything. I even removed the heat shield above the driveshaft. There is no contact anywhere, and the driveshaft has proper clearance throughout its length.
Its a brand new driveshaft, but the symptoms seemed that it could be out of balance. At the driveshaft shop, we removed and inspected the driveshaft thoroughly. There is zero play in the U-joints, and the driveshaft spun true and straight on the balancer. The driveshaft was re-balanced at a higher sensitivity, and balanced perfectly fine. Every nut and bolt was double checked and re torqued.
After putting everything back together, the issue is still present, and the car still violently shakes after 50mph.
Has anyone else ran into this issue? Other than lighting the car on fire, I am out of ideas on what to do next.
Any help greatly appreciated
'04 5mt MSM