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I just installed the Poly control arms and 4.5" springs. I have the JE Reel 1350 driveshafts what should the angle of the front drive shaft be. I have seen alot of info on the rear angles but not the front. Thanks
 

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It isn't the angle that most worry about it is the camber/caster that people worry about. Your driveshaft is so long that it usually doesn't cause any vibrations.
 

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With my JE Reel drive shaft I have to set the pinion angle at 5° or less otherwise I get excessive drive line vibration.


Driveshaft Angle: 10.1º
Pinion Angle: 4.5º

This gives me a caster of around 1.5°. It drives pretty good, a little light but not bad at all. I started at around 4º caster and it drove great, but there was a lot of drive line vibration. I also went down to 0º caster, but the steering was scary light and dangerous.

If I increase caster the steering gets more positive, but I start to introduce driveline vibration. If I improve the pinion angle then the steering gets too light.

With factory driveshafts you will get more caster without any drive line vibration.
 

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Might you care to suggest (or make a guess) as to what length upper control arms should be to achieve this angle with true 3 inch of lift and adjustable uppers/stock lowers?

I will play with it if I must. But a good starting point would be appreciated.


With my JE Reel drive shaft I have to set the pinion angle at 5° or less otherwise I get excessive drive line vibration.


Driveshaft Angle: 10.1º
Pinion Angle: 4.5º

This gives me a caster of around 1.5°. It drives pretty good, a little light but not bad at all. I started at around 4º caster and it drove great, but there was a lot of drive line vibration. I also went down to 0º caster, but the steering was scary light and dangerous.

If I increase caster the steering gets more positive, but I start to introduce driveline vibration. If I improve the pinion angle then the steering gets too light.

With factory driveshafts you will get more caster without any drive line vibration.
 

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With 4.5" of lift I'm at:

Lower - 23.25"
Upper - 19.25"

This moves the axle forward to where it should be, but i can't go any further forward as the sway bar link would contact the coils.

Can't recall what the stock lowers are off hand, but use the same differential between upper/lower and you should be close, maybe shorten the upper by 1/8" or 3/16" for 3".
 

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What drivelines are you guys running? The ones with the bolt on flanges or the ones with replacement yokes?
 

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What drivelines are you guys running? The ones with the bolt on flanges or the ones with replacement yokes?
I'm running ones with the OE flanges, and I know about the problem with the OE flanges being out of true. That doesn't seem to be causing me a problem and I've ran a dial across the flanges and calipered their thickness and mine seem to be good. I believe it t is the elliptical path of the axle end UJ that seems to be causing the vibration when the pinion angle gets too far off.
 
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