DC-Shaft pinion check (1 Viewer)

[landtank]

I've had a few questions about vibrations and whether or not a DC shaft is the solution/problem.

So I decided to post up how I evaluate the pinion angle to confirm if the pinion is aligned correctly for a DC shaft to operate without any vibrations.

The technical aspect of this is that a DC (double cardan) shaft requires an operating angle at the differential pinion to be 0* +/- 1*.

An easy way to confirm this is to use a digital angle finder like the ones sold at Harbor Freight.

The procedure is to park the truck so that you can place the finder on the pinion flange next to the drive shaft yoke to get an accurate reading.

Then take a reading with the left side of the finder on the pinion flange

and then compare that reading with another one taken with the top of the finder on the underside of the drive shaft tube.

You don't really care about the amount of angle but only the difference between the two.

I took the readings of my son's truck today. When comparing the two readings the operating angle of the front U-joint is .4* well under the 1.0* limit.


Hope this helps

 

[Road Apple]

Reviving an old thread since pinion angle has been a much discussed topic lately.

Good gouge!! Thank you @landtank for posting this and to @Surfdc for pointing it out on another thread.

 

[landtank]

Reviving an old thread since pinion angle is a much discussed topic recently.

Good gouge!! Thank you @landtank for posting this and to @Surfdc for pointing it out on another thread.

I'm glad you found it useful

 

[landtank]

Bringing this back to the top as I’ve had some questions.

 

[Rusty Marlin]

So, how do you fix it if its off?

 

[landtank]

So, how do you fix it if its off?

You have to change you caster correction method.

This is the rub. Focusing on Caster only when setting up your truck can put you in a situation where both types of drive shafts will vibrate.

The zone from 3 to 3-1/2” of lift is were you have to sacrifice caster if you want to avoid part timing the truck.

The safe lifts are 2-1/2” and 4” lifts.

 

[Rusty Marlin]

I had a feeling you were going to say that.....

 

[OGBeno]

Nice Rick. Clearly stated.