Front Pinion Angle

LarryG

LarryG

New member
So I installed my PR60s this week. Now that I have the Jeep back on tires, I measured the angle of the front and rear pinion and compared those angles to the angle of the transfer case output. On the rear, I assumed as I added a 3.5 lift that I would start by adding two turns to the Currie adjustable upper. These two turns were from the stock length original arm. It seems that was too much as my transfer case is at 92 degrees and the rear pinion angle is 86 degrees, meaning the rear pinion is angled upward compared to the transfer. I will take some turns out (shorten) the Currie, starting with the two I added.

On the front - the pinion angle is 79 degrees and the transfer case output is at 87 degrees. The transfer is aiming upward. I do not have adjustable control arms on the front, but even if I did, there is no way that I could pull the axle back far enough to offset the variance.

My questions are am I on track, here? Will the double cardan front drive shaft be the solution? Any experience on how many "turns" to bring the rear pinion angle to the sweet spot (it was a ROYAL P I T A getting the control arm to fit the first time and I am not looking forward to this adjustment).

Just a NOOB trying to build a Jeep!
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I dont have your answer but for claiming to be a noob your build looks and sounds awesome

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I'm not gonna lie, I didn't read your whole post because you totally lost me right from the get go. In the rear, you NEED to have your pinion angle in line with your drive shaft. You do this by setting your rear upper control arms until they get you to where you need to be. Up front, you need to be checking your CASTER and NOT the pinion angle. Your caster should be set at least to factory settings which would be +4° but really, being that you have manual locking hubs, I would set it to at least +6°.
 
I set my Currie rear lower arms to factory length and lengthened the uppers until my driveshaft was straight with my pinion. The front I set the caster with the front lowers, but I couldn't tell you how to measure that on your axle. I'm still on a stock axle not a nice one like a Dynatrac yet


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As Eddie stated just set your caster on the front and don't worry about pinion angle since you have lockout hubs. On the rear just adjust until you don't have a difference in angle on the u-joint at the pinion. For example if your rear driveline angle is 7 degrees, set your rear pinion to 97 degrees. Hard to tell what's up from your measurements because we don't know what your calling zero. The same angle could be reading 83 or 97 if that makes sense?


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So this is coming from someone who has spent way too much time adjusting control arms on new axles...your axle mounting points may be slightly different. You may want (or need, judging by what you said) to get all 8 arms. If you do, FIRST, set your lower lengths to center the wheel in the wheel well. And not just at ride height, but remove the springs and check clearances all the way up. Only then should you worry about perfecting the uppers to get the angles correct.

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wayoflife said:
I'm not gonna lie, I didn't read your whole post because you totally lost me right from the get go. In the rear, you NEED to have your pinion angle in line with your drive shaft. You do this by setting your rear upper control arms until they get you to where you need to be. Up front, you need to be checking your CASTER and NOT the pinion angle. Your caster should be set at least to factory settings which would be +4° but really, being that you have manual locking hubs, I would set it to at least +6°.
Click to expand...

Sorry I did a poor job of describing my attempt to measure the pinion angles. I will indeed use "caster" as my guide up front.

On the rear, I am using an angle tool that has one flat side, a pointer, and a plumb weight. I hold the flat side against the yoke coming out of the transfer case and read the number the pointer shows. I do the same thing on the yoke on the pinion end. So....I need to adjust the upper control arm until the angle is the same as the transfer case yoke. Correct?

If I still am not describing this right....sorry, I'm trying.
 
Speedy_RCW said:
As Eddie stated just set your caster on the front and don't worry about pinion angle since you have lockout hubs. On the rear just adjust until you don't have a difference in angle on the u-joint at the pinion. For example if your rear driveline angle is 7 degrees, set your rear pinion to 97 degrees. Hard to tell what's up from your measurements because we don't know what your calling zero. The same angle could be reading 83 or 97 if that makes sense?


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Click to expand...

I do not understand. The 7 degrees and 97? Sorry.
 
This should help you up front:
http://wayalife.com/showthread.php?3861-Basic-Do-it-Yourself-Jeep-JK-Wrangler-Front-End-Alignment

Your rear pinon and drive shaft should have the same angle. This is what it should look like:
main.php
 
So do I need to wait until my drive shaft is here, and installed before I can set the pinion angle. I currently do not have it installed. I needed to get ithe Jeep standing to measure the length of shafts to order.
 
LarryG said:
Sorry I did a poor job of describing my attempt to measure the pinion angles. I will indeed use "caster" as my guide up front.

On the rear, I am using an angle tool that has one flat side, a pointer, and a plumb weight. I hold the flat side against the yoke coming out of the transfer case and read the number the pointer shows. I do the same thing on the yoke on the pinion end. So....I need to adjust the upper control arm until the angle is the same as the transfer case yoke. Correct?

If I still am not describing this right....sorry, I'm trying.
Click to expand...

LarryG said:
I do not understand. The 7 degrees and 97? Sorry.
Click to expand...

Don't read into it too much. Don't worry about the measurement nor the transfer case yoke. You just need your pinion gear pointing right at your driveshaft. It all should look like a straight line.

IMG_20161015_192139_670.jpg
 
LarryG said:
I do not understand. The 7 degrees and 97? Sorry.
Click to expand...

He was just saying you will be 7 degrees off of 90 depending on which way you put the gauge on to measure it. 90 +/- 7 = 83 or 97 depending on where you place the gauge.
 
WJCO said:
He was just saying you will be 7 degrees off of 90 depending on which way you put the gauge on to measure it. 90 +/- 7 = 83 or 97 depending on where you place the gauge.
Click to expand...

Thank you. I've been over thinking this....and not very good at explaining.
 
WJCO said:
He was just saying you will be 7 degrees off of 90 depending on which way you put the gauge on to measure it. 90 +/- 7 = 83 or 97 depending on where you place the gauge.
Click to expand...

Precisely what WJCO said here. This is of course assuming you're reading at the pinion flange/yoke face. You can get your angles close prior to getting the new shaft but just check the angle once you install it. And I'm not sure what kind of angle finder you're using but there's lots of apps for your smartphone that will turn it into an easy to use angle finder.


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Speedy_RCW said:
Precisely what WJCO said here. This is of course assuming you're reading at the pinion flange/yoke face. You can get your angles close prior to getting the new shaft but just check the angle once you install it. And I'm not sure what kind of angle finder you're using but there's lots of apps for your smartphone that will turn it into an easy to use angle finder.


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Click to expand...

Thank you- much appreciated.
 
LarryG said:
Thank you. I've been over thinking this....and not very good at explaining.
Click to expand...

Pro-tip, when trying to get the control arms to line up, use a ratchet strap to the frame and wrapped around the axle.
You can pull it either direction to get the bolts slid through.
 
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