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front pinion angle

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Old Jan 12, 2012 | 07:26 PM
  #1  
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From: Chicago IL
Year: 1997
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Default front pinion angle

Hey guys just put my front drive shaft in and I went to drive the jeep and Woooow! All I can say is hello vibrations. I have a 4.5in lift with adjustable lower arms and stock uppers. Here's a pic of the angle. Will upper arms fix this?

front pinion angle-forumrunner_20120112_192652.jpg
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Old Jan 12, 2012 | 07:29 PM
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Cant really tell from that pic. try to get something better, more level.
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Old Jan 12, 2012 | 07:47 PM
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I snapped it real fast. We are in the middle of a blizzard lol.
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Old Jan 12, 2012 | 11:02 PM
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Your problem is your caster angle is off..
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Old Jan 12, 2012 | 11:05 PM
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looks high to me, vibe b4 shaft install
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Old Jan 12, 2012 | 11:34 PM
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So how do i correct that? Adjustable upper arms?
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Old Jan 12, 2012 | 11:48 PM
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adjust lowers
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Old Jan 13, 2012 | 07:40 AM
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don't forget, you are now running your u-joints in a different pattern unlike what they were used to.
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Old Jan 13, 2012 | 07:52 AM
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I believe the guy at Tom woods told me that on level ground that your pinion on you axle should match the angle of the pinion on the t case. Like if it points 7 degree down the axle pinion needs to point 7 degree up. So they are parallel. I did mine like this and no vibe. Also I think my caster I set at -4 degree( top one 4 degree behind bottom one) no vibes at all.
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Old Jan 13, 2012 | 07:54 AM
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And I do believe it is a max of 9 degree per joint or it will vibe.
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Old Jan 13, 2012 | 08:53 AM
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short answer, you want your pinion pointing towards your output. the double cardan joint will take care of the angle at the t-case. (more for the rear tho).

for the front, if it's off too bad, you want to turn the knuckles.
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Old Jan 13, 2012 | 09:28 AM
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Originally Posted by freegdr
adjust lowers
I need to adjust the lowers in or out? I think they are set at 16.5" for the 4.5in of lift
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Old Jan 13, 2012 | 11:26 AM
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But you only point the pinion at the output if you have the double carden. The single will vibe to death if you do.that.
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Old Jan 13, 2012 | 11:38 AM
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Originally Posted by Trev1006
But you only point the pinion at the output if you have the double carden. The single will vibe to death if you do.that.
I have a HP 30 with the double carden driveshaft.
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Old Jan 13, 2012 | 11:43 AM
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Ok, then like caged said point that pinion right at the t case. How is your front caster? Have you checked it?
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