Fixing my rear pinion angle.
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Year: 2000
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Fixing my rear pinion angle.
Im at 4.5" with a sye kit installed. I checked my rear pinion angle cuz im getting some bad vibrations at speed and there is about a 4* degrees difference. I read the lifting the pinion decreases the driveshaft angle at the same time. So my question is would a 2* shim work? from what Ive read this seems to be the way to go.
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Year: 1999
Model: Cherokee
Engine: 4.0
Im at 4.5" with a sye kit installed. I checked my rear pinion angle cuz im getting some bad vibrations at speed and there is about a 4* degrees difference. I read the lifting the pinion decreases the driveshaft angle at the same time. So my question is would a 2* shim work? from what Ive read this seems to be the way to go.
I'm at 4.5" lift and I have 4 deg shims and it's perfect.
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Year: 1999
Model: Cherokee
Engine: 4.0L
1) get an a magnetic inclinometer (angle meter)
2) park on level ground
3) attach inclinometer to driveshaft and note displayed angle
4) find a (hopefully flat) spot on your diff that allows you to attach the inclinometer to read the pinion angle. Note, base of the inclinometer MUST be parallel to the pinion, otherwise you may have to eyeball it.
5) take the two angles you got and do the math. The pinion angle should be set a little below parallel to the driveshaft to compensate for axle wrap under acceleration.
2) park on level ground
3) attach inclinometer to driveshaft and note displayed angle
4) find a (hopefully flat) spot on your diff that allows you to attach the inclinometer to read the pinion angle. Note, base of the inclinometer MUST be parallel to the pinion, otherwise you may have to eyeball it.
5) take the two angles you got and do the math. The pinion angle should be set a little below parallel to the driveshaft to compensate for axle wrap under acceleration.
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#7
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cdn xj, I did that, actually disconnected the DS at the diff to measure the pinion angle. DS was 14* and pinion was 80*, different orientations. SO its a 4* difference.
I read that when you shim the axle to the pinion angle you change the DS angle so you dont need the full 4*. Also I want room for axle wrap. How much axle wrap is there with leaf springs?
I read that when you shim the axle to the pinion angle you change the DS angle so you dont need the full 4*. Also I want room for axle wrap. How much axle wrap is there with leaf springs?
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Year: 1998
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I have a 4.5 lift and used a 4 degree shim, I still have 2 degrees for axle wrap. I run OME light spring , so it depends what rate your rear springs are. If you don't hole shot your jeep you'll be ok.
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Year: 1999
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cdn xj, I did that, actually disconnected the DS at the diff to measure the pinion angle. DS was 14* and pinion was 80*, different orientations. SO its a 4* difference.
I read that when you shim the axle to the pinion angle you change the DS angle so you dont need the full 4*. Also I want room for axle wrap. How much axle wrap is there with leaf springs?
I read that when you shim the axle to the pinion angle you change the DS angle so you dont need the full 4*. Also I want room for axle wrap. How much axle wrap is there with leaf springs?
As for the vibes, are you sure it's the rear pinion and not your front? I had to live with driveline vibe for a while until i stopped being lazy and dealt with my front pinion angle. lol
Also, how are your u-joints? check all 6 to make sure they're not sloppy.
Last edited by cdn_xj; 02-08-2013 at 09:56 PM.
#10
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I can't remember offhand what the acceptable range is, but I should think you would be ok with 4*. I think I'm running about 2* or so.
As for the vibes, are you sure it's the rear pinion and not your front? I had to live with driveline vibe for a while until i stopped being lazy and dealt with my front pinion angle. lol
Also, how are your u-joints? check all 6 to make sure they're not sloppy.
As for the vibes, are you sure it's the rear pinion and not your front? I had to live with driveline vibe for a while until i stopped being lazy and dealt with my front pinion angle. lol
Also, how are your u-joints? check all 6 to make sure they're not sloppy.
Anyone have issues with shims cracking? I was talking with a friend of a friend and he said he doesnt like shims cuz the crack. Only had ont real example of it and I cant see steel shims cracking.
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I'm on a 3.5" RE superflex kit with full packs and preemptively bought 4° shims based on others' builds. They worked perfectly and are solid steel from RE.
#13
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None of those guys have been in the forum for quite a while. You may just have to keep searching and reading... and learning... and asking questions... plenty of info on this forum to figure out your problems. I am not lifted yet, so I cant help with your exact issue..
#14
Fixing Pinion Angle and Vibration in Drivetrain
Thanks for your reply. I am actually NOT lifted either. I am going to attempt to restore the rear to completely stock. I have longer rear shackles, but I am going to start with putting back the stock ones.
The only other question I have is... do the front springs also wear out? Do I need to get new FRONT springs to make it level again...
I am getting shims also, incase I need to use those to fine tune.
My goal is to make this JEEP Cherokee STOCK HEIGHT, and make it a strong tow vehicle... NOT a rock climber, or a lifted JEEP for now.
Thank you!
The only other question I have is... do the front springs also wear out? Do I need to get new FRONT springs to make it level again...
I am getting shims also, incase I need to use those to fine tune.
My goal is to make this JEEP Cherokee STOCK HEIGHT, and make it a strong tow vehicle... NOT a rock climber, or a lifted JEEP for now.
Thank you!
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be aware the Sports, (and some Limited) run 1" taller springs all round
If reverting to "stock" I would probably use them in any case
the best way to check is to get under and measure axle tube to frame rail heights, correct data is on this forum somewhere
If reverting to "stock" I would probably use them in any case
the best way to check is to get under and measure axle tube to frame rail heights, correct data is on this forum somewhere
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