Savvy tummy tuck / under armor install

mattcogdell

TJ Enthusiast
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Looking for some advice. After finishing up lunch today I'm going to begin my savvy tummy tuck and under armor install. The Jeep is a '05 TJ Rubicon. I've gone ahead and installed the Savvy BL, MML, 4wd shift cable. The Jeep has the 2" OME lift on it. I ordered Savvy's upper adjustable rear control arms and their rear trac bar and bracket kit.



I've never adjusted a pinion angle before nor ordered a custom drive shaft. So these are my thoughts. Disconnect rear drive shaft, measure my current pinion angle and the angle at the transfer case. Install the tummy tuck. Then install the upper arms and trac bar. Center my axle then set my pinion up towards the transfer case according to the needed angles for a double cardinal shaft. Measure my gap according to the info from Tom Woods and order a new DC shaft.



Am I missing anything or need to do anything differently or pay attention to something else? The biggest thing I'm confused about is setting the pinion angle.

I do have an angle finder.



Thanks for the advice and help in advance.
 
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I got the kit installed. Now I am just waiting on my drive shaft to arrive before bolting the skid on. Very happy with the fit and finish of this kit.
IMG_8700.webp
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You'll have to measure the rear drive shaft angle then the pinon angle on the rear diff. There are two circular areas on the left and right of the rear diff cover you can put your angle finder against to get the angle. You want your pinon 1* lower than your shaft angle. So if your shaft angle is 15*, you want your pinion to be 14*. Adjust your lower CAs to get the right angles.

Will you have to do any exhaust work to get the skid to fit correctly?
 
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You'll have to measure the rear drive shaft angle then the pinon angle on the rear diff. There are two circular areas on the left and right of the rear diff cover you can put your angle finder against to get the angle. You want your pinon 1* lower than your shaft angle. So if your shaft angle is 15*, you want your pinion to be 14*. Adjust your lower CAs to get the right angles.

Will you have to do any exhaust work to get the skid to fit correctly?

The jeep has/had a banks monster exhaust (catback). I did not even try to see if there was clearance. ad 2.5" turn down that I just bolted on. If the fumes or drone become unbarring I will run the exhaust out. From the supplied new exhaust bracket from savvy I doubt there is much need for modification honestly.
 
Adjust your upper control arms, not lower. You want the axle to pivot up but the axle to stay in the same place inside the wheel well.

Correct. The jeep still has all factory arms other than the uppers. I installed savvy uppers to adjust for the change in pinion angle.
 
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Did you happen to take any photos of the install process?

No I am bad about taking photos until after the fact. I did not even think to take a picture before the tuck. If there is anything specific you want to see I get some pictures.
 
Correct. The jeep still has all factory arms other than the uppers. I installed savvy uppers to adjust for the change in pinion angle.
If you had both upper and lower adjustables, you would be adjusting both. The idea that the uppers adjust one thing while the lowers do another is not correct. Both pairs get adjusted to establish the wheelbase. And both pairs get adjusted to roll the pinion up or down. It all happens at once.
 
No I am bad about taking photos until after the fact. I did not even think to take a picture before the tuck. If there is anything specific you want to see I get some pictures.
I thought that might be the case, or you would have already posted those. No issues. I would like to see a side view from lower down, so you can see across the bottom frame rails, if possible. And any other underside photos you feel would be interesting to look at. Thanks!
 
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It's always surprising how different a TJ looks without the factory skid.
 
If you had both upper and lower adjustables, you would be adjusting both. The idea that the uppers adjust one thing while the lowers do another is not correct. Both pairs get adjusted to establish the wheelbase. And both pairs get adjusted to roll the pinion up or down. It all happens at once.

I was under the impression I only needed uppers. Once the drive shaft gets here and I try adjusting the pinion angle, I may have to order the lowers if that is the case.
 
I was under the impression I only needed uppers. Once the drive shaft gets here and I try adjusting the pinion angle, I may have to order the lowers if that is the case.
Some get away with just the uppers, but that only works until it doesn't. The more spring lift the Jeep has, the more you will need both uppers and lowers. The amount of bump stop extension also factors in. The longer the bumps needed for the shocks, the more you ought to extend the wheelbase. It's a domino effect...
 
Some get away with just the uppers, but that only works until it doesn't. The more spring lift the Jeep has, the more you will need both uppers and lowers. The amount of bump stop extension also factors in. The longer the bumps needed for the shocks, the more you ought to extend the wheelbase. It's a domino effect...
Wouldn't adjusting the wheelbase affect the drive shaft length needed, or not so much that it would make a big difference?
 
Wouldn't adjusting the wheelbase affect the drive shaft length needed, or not so much that it would make a big difference?
Probably. Though we are talking fractions of an inch.
 
Wouldn't adjusting the wheelbase affect the drive shaft length needed, or not so much that it would make a big difference?

Your track bar is going to hit the gas tank skid before anything noticeable will happen with the ds.
 
Wouldn't adjusting the wheelbase affect the drive shaft length needed, or not so much that it would make a big difference?
As far as
Some get away with just the uppers, but that only works until it doesn't. The more spring lift the Jeep has, the more you will need both uppers and lowers. The amount of bump stop extension also factors in. The longer the bumps needed for the shocks, the more you ought to extend the wheelbase. It's a domino effect...
This is my attempt to do what is needed while keeping it minimal. The Jeep has 2 inch OME springs. The Jeep is extremely capable as is but my biggest holdups where the factory steering and skid getting hung up. I have full intensions of the mid arm but rather than throwing money at the Jeep I am enjoying learn how each upgrade benifits me from the past. If you hopped in a Jeep that was built prior or just threw money at it without wheeling, what would you gain aside from a sweet Jeep? Probably wouldn't learn anything ......