What degree of shim for a 3" lift?

[whiskies]

Gents, 94 cherokee with AA SYE and 3 inches of lift. 8.25 diff, 31 inch tires. double carden front drive shaft on the rear.
What degree of shim for a 3" lift? If i run it with out the pinion aimed at the T case will it beat it's self to death

 

[whitexj98]

Grab an angle finder and go measure it is the only way to get it accurate.

http://www.stu-offroad.com/axle/pinion/pinion-1.htm (TJ stuff but same concept using shims)

Having it off depending how much will give you drive shaft vibrations which isnt any good for the output shaft bearing or the u- joints.

 

[cal]

Like he said, you need to measure.

You want it pointed just a couple of degrees below the tcase, so that when you punch it and get a little axle wrap you're aligned correctly.

 

[whiskies]

Thanks for the replies guys, I have an angle meter but will not be able to get shims here till next week and I was hoping to get it done on the weekend as it is my daily driver. I will try it and hope for the best ....maybe

Dave

 

[cal]

If you're a degree or two off it won't matter much.

I'd start with 2*. If it looks way off order some 4's and try again the next weekend.

 

[beasticles]

Running 4* shim on a Rubicon Express 3.5" lift (which equates to about 4-4.5 inches in rear). Pinion is about 1* below zero, so about perfect.

 

[whiskies]

I swapped out the T-cases today Everything worked well, both had 23 spline count and the 231J already had a AA short shaft "fixed yoke" kit already installed, I need to order the proper gear for the speedo though as previous owner had it geared for 32" tires where as I am running 31". The rear double cardan joint shaft looks like it is stretched out to the limit which makes me a little nervous.
Now I have another question I hope someone can help me with?

Here is the measurements I got using an angle meter, can you tell me what degree of shim I require? and please explain to me how you got the measurement?

Can I use the same formula for the front diff as well? I realize there is steering angles involved, I have had the front end alignment and it tracks well however not sure about the caster angle as alignment shop said it was within specs. I have adjustable lower control arms

 

[whiskies]

I swapped out the T-cases today Everything worked well, both had 23 spline count and the 231J already had a AA short shaft "fixed yoke" kit already installed, I need to order the proper gear for the speedo though as previous owner had it geared for 32" tires where as I am running 31". The rear double cardan joint shaft looks like it is stretched out to the limit which makes me a little nervous.
Now I have another question I hope someone can help me with?
Here is the measurements I got using an angle meter, can you tell me what degree of shim I require? and please explain to me how you got the measurement?

Can I use the same formula for the front diff as well? I realize there is steering angles involved, I have had the front end alignment and it tracks well however not sure about the caster angle as alignment shop said it was within specs. I have adjustable lower control arms

 

[whiskies]

I swapped out the T-cases today Everything worked well, both had 23 spline count and the 231J already had a AA short shaft "fixed yoke" kit already installed, I need to order the proper gear for the speedo though as previous owner had it geared for 32" tires where as I am running 31". The rear double cardan joint shaft looks like it is stretched out to the limit which makes me a little nervous.
Now I have another question I hope someone can help me with?
Here is the measurements I got using an angle meter, can you tell me what degree of shim I require? and please explain to me how you got the measurement?
will not let me load pic??????????
Can I use the same formula for the front diff as well? I realize there is steering angles involved, I have had the front end alignment and it tracks well however not sure about the caster angle as alignment shop said it was within specs. I have adjustable lower control arms

 

[the_weirdo]

I swapped out the T-cases today Everything worked well, both had 23 spline count and the 231J already had a AA short shaft "fixed yoke" kit already installed, I need to order the proper gear for the speedo though as previous owner had it geared for 32" tires where as I am running 31". The rear double cardan joint shaft looks like it is stretched out to the limit which makes me a little nervous.
Now I have another question I hope someone can help me with?
Here is the measurements I got using an angle meter, can you tell me what degree of shim I require? and please explain to me how you got the measurement?

Can I use the same formula for the front diff as well? I realize there is steering angles involved, I have had the front end alignment and it tracks well however not sure about the caster angle as alignment shop said it was within specs. I have adjustable lower control arms

Let's start with the rear axle: We can't see your file. Save it to an online photo service like Photobucket, etc and paste the URL in a new post. It will look like this:

.

I would order both 2 degree and 4 degree shims if you need it to be done fast. You'll probably use the 2 degree shims if you don't have any shims installed yet and the lift is really only 3".

For the front: If the lift is on and the front alignment numbers are good, you are fine.

 

[whiskies]

http://s1275.photobucket.com/user/davemuir64/media/drivetrainanglefinalgif_zps6798f2eb.jpg.html

Not sure I am doing this right, appreciate all the help

the numbers I got are 6 degrees down tc, 16 degrees down on the driveshaft, pinion 5 degrees up, everywhere I look I am told to aim the pinion directly at TC output which would be 11 degrees which seem excessive OR am I missing something?

I swapped out the T-cases today Everything worked well, both had 23 spline count and the 231J already had a AA short shaft "fixed yoke" kit already installed, I need to order the proper gear for the speedo though as previous owner had it geared for 32" tires where as I am running 31". The rear double cardan joint shaft looks like it is stretched out to the limit which makes me a little nervous.
Now I have another question I hope someone can help me with?
Here is the measurements I got using an angle meter, can you tell me what degree of shim I require? and please explain to me how you got the measurement?

 

[93gc40]

are you getting vibes? If not I'd leave it alone cause your numbers are text book. Now the fully extended shaft signifies you have too short a shaft. I would avoid flexing the rear until you address that.

 

[whiskies]

Yes getting some vibrations, I disconnected the front ds to isolate it. I was told to point the rear diff toward the t case because I am using a double cardan joint and your saying not to ? I have lined up drives hafts before but usually just parallel to each other, appreciate the help

 

[beasticles]

Yes getting some vibrations, I disconnected the front ds to isolate it. I was told to point the rear diff toward the t case because I am using a double cardan joint and your saying not to ? I have lined up drives hafts before but usually just parallel to each other, appreciate the help

What you originally thought - is correct. You want the rear diff to be pointing at the t-case essentially.

Here is a representative image of the stock driveshaft setup - with the CV driveshaft you have you should NOT look like this:

Here is a representative image of how your CV driveshaft should look - you can accomplish this increased angle by adding shims under the rear leaf springs as you are contemplating:

As other's have recommended, if you are only at 3" a 2* shim should work - but to be safe you may want to order both 2* and 4* to save time and then return the one you don't need later.

I personally opted for slightly more expensive shims from Iron Rock Offroad and was very pleased with the quality of the kit. Plus it comes with the correct longer center pins you will need.

 

[whiskies]

Is there a formula that I can input my numbers?

http://s1275.photobucket.com/user/davemuir64/media/drivetrainanglefinalgif_zps6798f2eb.jpg.html