Drivetrain Shifter rattles at high speeds

[ChaseRoads]

Car details. 91 5.0 vert. Fresh tkx swap. Maybe 500 miles on swap.

When doing 65mph or above, the shifter will rattle. It’s me not enough that a hand on the shifter stops it but it’s bad enough that something definitely seems off. It does not do it while parked and reving. It does not change with the clutch in or out. I would think it’s driveshaft related.

I plan to inspect the rear u joints , and check the driveshaft marks to see if it’s 180 out. Is it possible the driveshaft is unbalanced? It’s the stock one that we swapped the yoke to use with the swap.

 

[KRUISR]

How are your pinion and driveshaft angles?

 

[ChaseRoads]

I’ve not properly measured them. The issue I’m fighting is being able to reach them. I don’t have access to a drive on lift.

 

[ChaseRoads]

I tried to reach under and use the tremec app but these numbers seem wrong. I’ll have to try again.

For the trans, the tail shaft.

Driveshaft , anywhere

And where in the diff?

 

[KRUISR]

You don't need a drive on lift (it does help though). Jack up the car and place jack stands under the rear axle (to load it as if on the ground) and under the front crossmember (I usually support in the space between the two lower control arm mounts).

The rear can get measured on the flange where the driveshaft bolts to. From my understanding you don't want the angle at each u-joint any more than 3 degrees, any more and vibration will occur at higher speeds.

I found this calculator and site helpful.

Spicer Driveline Operating Angle Calculator

Measure the angles of each component in your drivetrain, then use the Spicer Driveline Operating Angle Calculator to find the operating angle of each u-joint in your drivetrain.

spicerparts.com

 

[limp]

 

[Imatk]

Check the pinion, also check the U-Joints, make sure they aren't broken/loose etc... ask me how I know