Stupid pinion angle question

[Jason4x4]

Toyota 4Runner, 4.3/4l60/np241, has a toyota driveshaft with a SYE on the np241 with a toyota flange. On Decel, I get drive line vibrations, best I can tell, pinion is pointed at the t-case, on accell, it's smooth, on coast it's smooth, on Heavy decel, like cruising at 75mph, let off throttle, heavy vibs, roll into throttle even a little bit, vibs go away.

Which way do I need to shim the pinion? up or down?

 

[ToyodaAddict1980]

With a cv at the tcase set the pinion 2* below the slope of the shaft.

 

[TheeCaseyH]

If you have a double cardon style shaft, your pinion should be pointed straight at the tcase flange. If it is a regular 2 joint shaft, your pinion flange should be roughly the same angle as you tcase flange angle.

Driveline Geometry 101

Driveshaft Angle Explained This video will demonstrate the proper angles for a drive shaft in a stock Jeep or Truck and how the rules change when you add a suspension lift. The video below demonstrates what is happening to the shaft at different angles, how improper angles can cause speed...

4xshaft.com

Vibrations (Harmonic)

Please bear with me! I'm really going somewhere here but there are a few precepts that we have to understand. Vibrations can be and often are the sum of different sources. Try to imagine this if you will... If you were to graph out a vibration, it will have an amplitude (strength) and a wave...

4xshaft.com

 

[Jason4x4]

If you have a double cardon style shaft, your pinion should be pointed straight at the tcase flange. If it is a regular 2 joint shaft, your pinion flange should be roughly the same angle as you tcase flange angle.

Driveline Geometry 101

Driveshaft Angle Explained This video will demonstrate the proper angles for a drive shaft in a stock Jeep or Truck and how the rules change when you add a suspension lift. The video below demonstrates what is happening to the shaft at different angles, how improper angles can cause speed...

4xshaft.com

Vibrations (Harmonic)

Please bear with me! I'm really going somewhere here but there are a few precepts that we have to understand. Vibrations can be and often are the sum of different sources. Try to imagine this if you will... If you were to graph out a vibration, it will have an amplitude (strength) and a wave...

4xshaft.com

Yes, double cardan at the tcase, and near as I can tell, it is pointed straight at the output

 

[Jason4x4]

With a cv at the tcase set the pinion 2* below the slope of the shaft.

I can try that, just put an angle finder on the thrid member flange? and set 2* less then the driveline angle, correct?

 

[ToyodaAddict1980]

I can try that, just put an angle finder on the thrid member flange? and set 2* less then the driveline angle, correct?

Yes, that is how Jess at high angle told me to do it and it has always worked.
In my experience, just eyeballing the pinion flange toward the tcase output isnt good enough. Just a degree or two off can make the difference.
I will add that this method is for leaf sprung trucks.

 

[Jason4x4]

Yes, that is how Jess at high angle told me to do it and it has always worked.
In my experience, just eyeballing the pinion flange toward the tcase output isnt good enough. Just a degree or two off can make the difference.
I will add that this method is for leaf sprung trucks.

1 more, hypothetically, so let's say the flange is at 10*, and the drive shaft is at 10 , so I need to go down 2, will a 2* shim = 2* at the pinion flange? or how do I figure out what shim to get?

 

[Yotota]

1 more, hypothetically, so let's say the flange is at 10*, and the drive shaft is at 10 , so I need to go down 2, will a 2* shim = 2* at the pinion flange? or how do I figure out what shim to get?

Yes. The angle shim rotates the axle the same amount of degrees as the shim itself. So if you need the pinion to go down 2°, get a 2° shim and run it thick side forward.

 

[Jason4x4]

With a cv at the tcase set the pinion 2* below the slope of the shaft.

Just put an angle finder on it, driveshaft is at 17*, rear yoke flange is at 16*.

What should I do to get rid of the vibration on Decel?

 

[Yotota]

Just put an angle finder on it, driveshaft is at 17*, rear yoke flange is at 16*.

What should I do to get rid of the vibration on Decel?

Sounds like you're getting axle wrap on decel, allowing your pinion to point downward.

Do you have spring clamps? Pulling those to get more leaf travel results in more axle wrap too.

Or you could install a traction bar.

 

[Jason4x4]

Sounds like you're getting axle wrap on decel, allowing your pinion to point downward.

Do you have spring clamps? Pulling those to get more leaf travel results in more axle wrap too.

Or you could install a traction bar.

I'll have to check on the spring clamps. I am running chevy 63's, I think 1 side has the clamp, i think the passenger side is gone cuz it was hitting the gas tank. Maybe I can find someone with a go pro and video it.