Rear driveshaft angle measurements needed with Savvy under armor

[Irun]

I've installed the following:

- 31" tires
- H&R 1" springs (netted 1.5")
- Aluminum spring spacer
- Savvy UA
- Rubicon Dana 44
- 241OR
- Currie rear track bar
- Currie rear track bar bracket
- Savvy double adjustable control arms
- Tom Woods rear driveshaft (16")
- Yukon small hub kit
- Tom Woods front driveshaft (41.5")

When settng the rear pinion angle, I had to stop at 16.5°, because lower arms are adjusted all the way in, and the track bar bracket barely clears the gas tank cross member at full bump. Now that I have the rear shaft in, it is clearly not in line like it should be. At this point, the rear shaft measures 21.5°, while the pinion is at 16.5°. I took it for a couple short drives and there is a very slight vibration.

Given the angles need to be in alignment, I'm curious what pinion angles others with a Savvy UA have? FWIW, I know it's the rear, because the front hubs are unlocked.

 

[SvtLdr]

Perhaps I'm misunderstanding you. You mentioned that your upper arms are all the way in (as short as they can be)? Isn't that going to effectively bring your pinion down?

I recently installed a tummy tuck also - not the Savvy UA though. I too struggled to find the balance between "GTS/ track bar collision land" and "happy driveshaft angle." I read about other folks who suggested a combination of shortening the lower arms while lengthening the uppers. I ended up being able to grind a few spots on my GTS to just get by and didn't have to touch the lower arms.

I could measure the angle on my driveshaft for you but I'm not sure it would help. I went with a flat belly skid so I imagine my (smaller 231) transfer case is a little higher than yours. Keep us posted here on your progress.

 

[mrblaine]

I've installed the following:

- 31" tires
- H&R 1" springs (netted 1.5")
- Aluminum spring spacer
- Savvy UA
- Rubicon Dana 44
- 241OR
- Currie rear track bar
- Currie rear track bar bracket
- Savvy double adjustable control arms
- Tom Woods rear driveshaft (16")
- Yukon small hub kit
- Tom Woods front driveshaft (41.5")

When settng the rear pinion angle, I had to stop at 16.5°, because lower arms are adjusted all the way in, and the track bar bracket barely clears the gas tank cross member at full bump. Now that I have the rear shaft in, it is clearly not in line like it should be. At this point, the rear shaft measures 21.5°, while the pinion is at 16.5°. I took it for a couple short drives and there is a very slight vibration.

Given the angles need to be in alignment, I'm curious what pinion angles others with a Savvy UA have? FWIW, I know it's the rear, because the front hubs are unlocked.

No idea what any of the angles are since I rarely use an angle finder but you have a very unique build and may need to shorten the arms. If you aren't comfy doing that, I'm glad to do it for you.

 

[Irun]

Perhaps I'm misunderstanding you. You mentioned that your upper arms are all the way in (as short as they can be)? Isn't that going to effectively bring your pinion down?

My lower arms are all the way in. Uppers are extended.

 

[mrblaine]

My lower arms are all the way in. Uppers are extended.

I can fix that.

 

[SvtLdr]

My lower arms are all the way in. Uppers are extended.

Gotcha, sorry about that.

Is it possible to create some clearance at the skid?

Is it possible that your vibes are coming from the new transmission mount?

My guess is that your lower lift height is the culprit here? So even if others that have the Savvy UA chime in on what their angle is, it's unlikely that they're also on 1" springs?

 

[Irun]

I can fix that.

I'll send you a note later. It's clear to me that the lowers need to be shortened!

 

[Irun]

I can fix that.

If memory serves me correctly, I believe the lowers are currently set at 15" eye to eye.

 

[sierradmax]

I don't have a Savvy skid or double adjustable control arms. What I noticed comparing a 231, a 241 and an atlas, is that with a double cardan Driveshaft & the 241, the centering ball to the CV is pretty far back resulting in steeper driveshaft angles.

 

[erokj]

This is probably a dumb question, but could you get away with running a stock Rubicon rear DS if the double cardan DS requires too many mods?

Not sure if it makes a difference, but I used Savvy UA and Savvy control arms with a stock rear Rubicon DS.. but I have an LJR.

 

[JMT]

I've installed the following:

- 31" tires
- H&R 1" springs (netted 1.5")
- Aluminum spring spacer
- Savvy UA
- Rubicon Dana 44
- 241OR
- Currie rear track bar
- Currie rear track bar bracket
- Savvy double adjustable control arms
- Tom Woods rear driveshaft (16")
- Yukon small hub kit
- Tom Woods front driveshaft (41.5")

When settng the rear pinion angle, I had to stop at 16.5°, because lower arms are adjusted all the way in, and the track bar bracket barely clears the gas tank cross member at full bump. Now that I have the rear shaft in, it is clearly not in line like it should be. At this point, the rear shaft measures 21.5°, while the pinion is at 16.5°. I took it for a couple short drives and there is a very slight vibration.

Given the angles need to be in alignment, I'm curious what pinion angles others with a Savvy UA have? FWIW, I know it's the rear, because the front hubs are unlocked.

My rear pinion is around 18.5*
The shaft is 19” long
3.25” lift in the rear

 

[Irun]

This is probably a dumb question, but could you get away with running a stock Rubicon rear DS if the double cardan DS requires too many mods?

Not sure if it makes a difference, but I used Savvy UA and Savvy control arms with a stock rear Rubicon DS.. but I have an LJR.

There's a 10" difference in the wheelbase between your LJ and a TJ. This means your stock driveshaft is significantly longer and, as such, would work. A stock TJR driveshaft would not.

 

[Irun]

My rear pinion is around 18.5*
The shaft is 19” long
3.25” lift in the rear

You cheated.....you have a SS SYE!

 

[erokj]

There's a 10" difference in the wheelbase between your LJ and a TJ. This means your stock driveshaft is significantly longer and, as such, would work. A stock TJR driveshaft would not.

You should probably sell it and buy an LJ, boom all your problems solved!

 

[Irun]

You should probably sell it and buy an LJ, boom all your problems solved!

That was easy, problem solved!

 

[erokj]

That was easy, problem solved!

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