Pinion/tailshaft questions

[osaltyone]

At the point where I need to set the ride height before I mount the cab and was wondering.

On the 4l60e where do I measure the angle? Also on the rear do I measure on the drive shaft or at the point on the rear? Also, is that yolk out too far in the trans? it is about 4" long and about 2 of it is out.

4L60e tailshaft


Rear

[osaltyone]

Anyone?
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[Portmod7]

In the first pic, put your angle finder on the vertical surface that is the end of the tail housing on the tranny. If the edge of the seal is beat up or otherwise not flush in the housing it may affect the results a little, but from your picture it looks ok.

In the second picture, with the pinion yoke rotated so that the u-joint caps are exactly horizontal of one another, pretty much like you have it in the pic, pull of one of the u-joint retaining caps/straps and place your angle finder on the vertical surface of the yoke where the retaining cap/strap mounts to.

The goal is to have both measurements reading the same, or the rear slightly less to account for axle wrap on acceleration (1 deg or less difference).

I would say your transmission yoke is not deep enough. The last time I dealt with a driveline shop, they wanted the measurement with the yoke bottomed in the transmission, and subtracted 3/4" from that to get the driveline length. Without your springs in, you could travel the rear suspension and measure how much it moves the transmission yoke, I would say you'd only want the amount of movement plus 1/4" sticking out. The more you can stuff in the transmission without bottoming it out the better.

[dragginmetal]

If this is a 1pc driveshaft, You start at the u-joint by the trans tailshaft.
Put your angle finder on the side of the u-joint and rotate the driveshaft till you get 90*.



Next put the angle finder on the same u-joint but at the bottom.
This is your first angle.
Mines at 4*.



Then move to the u-joint at the rear.
Place the angle finder on the bottom of the rear u-joint.
This is the 2nd angle.
Mines at 2*.
The rear u-joint needs to be pointed down 1*-4* more.
This needs to be done with the suspension loaded (and at ride height if bagged).


EDIT**portmod7 beat me to it..

[Portmod7]

Basically with a one piece shaft, the way I've always understood pinion angle, is the output shaft on the transmission, and the pinion on the differential need to be parallel to each other when looked at from the side. If the transmission is down to the rear of the truck x degrees, the pinion needs to point up toward the front of the truck the same x degrees.

Here's an awesome link from Spicer. Starting at page 5 will probably answer your question.
http://65.170.161.218/~spicerpa/site...stallation.pdf

[osaltyone]

Thanks! This helps. I was measuring from the bottom of the tailshaft and yolk. This is a 1 piece drive shaft on a bagged truck. Dropmember in the front and KP in the rear. My pics were at ride height 6" from the ground measured from the front cab support area. In talking with Nate in the past I think he said 4 degrees down at the tailshaft.

[tinydb84]

Not to highjack but how does this work with a two piece driveshaft?
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[Portmod7]

Originally Posted by tinydb84

Not to highjack but how does this work with a two piece driveshaft?
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http://65.170.161.218/~spicerpa/site...stallation.pdf

It's marked as Page 13, but it's actually page 16 of the document.

[tinydb84]

Originally Posted by Portmod7

http://65.170.161.218/~spicerpa/site...stallation.pdf

It's marked as Page 13, but it's actually page 16 of the document.

Thanks! I couldnt open the link on my phone but got it now.