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-   -   Adjustable rear control arms (http://www.wranglerforum.com/f210/adjustable-rear-control-arms-231880.html)

WVU Mountainman 03-31-2013 10:11 PM

My pinion angle is still too high compared to my TC output. I have a stock driveshaft, 2" coil lift, 1" MML and 1" TC skid drop.Will adjustable rear CA allow me to rotate the pinion angle downwards? Recommended brands?

TJspeed 03-31-2013 10:12 PM

Between the mml and 1" tc drop you should be close to stock.

WVU Mountainman 03-31-2013 10:14 PM

Quote:

Originally Posted by TJspeed (Post 3577468)
.

Yes sir. Stock

TJspeed 03-31-2013 10:15 PM

Sorry I had asked about the control arms before you posted the picture.

WVU Mountainman 03-31-2013 10:16 PM

Quote:

Originally Posted by TJspeed (Post 3577468)
Between the mml and 1" tc drop you should be close to stock.

From the information I've gathered from this site my pinion angle and TC output angle need to be on the same plane. I still get vibes at 50 mph.

marlboroman 03-31-2013 10:20 PM

i am in this dilemma as well i have the RE adjustable rear upper ca's but not the lowers just the ones that came with the lift kit ive heard lots of things as far as this problem goes and for me im looking into an sye and a cv shaft but im not sure if just doing adjustable lowers will help the shaft angle. From the pic and what mine looks like i think that if u adjust the top side it will only fix one side but this is all speculation i will test it out next monday when i get some time off if i can remember i will post results since i have them installed already and no sye or cv shaft is on order its worth a shot let you know in about a week.

WVU Mountainman 03-31-2013 10:24 PM

Quote:

Originally Posted by marlboroman (Post 3577500)
i am in this dilemma as well i have the RE adjustable rear upper ca's but not the lowers just the ones that came with the lift kit ive heard lots of things as far as this problem goes and for me im looking into an sye and a cv shaft but im not sure if just doing adjustable lowers will help the shaft angle. From the pic and what mine looks like i think that if u adjust the top side it will only fix one side but this is all speculation i will test it out next monday when i get some time off if i can remember i will post results since i have them installed already and no sye or cv shaft is on order its worth a shot let you know in about a week.

Not sure what you mean by fixing one side? I thought the upper CA's adjust pinion angle and the lowered were for moving the axle forwards and backwards?

Patrick H 03-31-2013 10:27 PM

Quote:

Originally Posted by WVU Mountainman (Post 3577514)
Not sure what you mean by fixing one side? I thought the upper CA's adjust pinion angle and the lowered were for moving the axle forwards and backwards?

You can do both adjustments with either the uppers or the lowers, technically. I installed adjustable lowers, and lengthened them a bit to lower pinion angle. Just be careful not to push the axle back far enough to cause interference with the fuel tank

WVU Mountainman 03-31-2013 10:31 PM

Quote:

Originally Posted by Patrick H (Post 3577534)

You can do both adjustments with either the uppers or the lowers, technically. I installed adjustable lowers, and lengthened them a bit to lower pinion angle. Just be careful not to push the axle back far enough to cause interference with the fuel tank

Which would give me the most adjustment? Uppers or lowers?

Patrick H 03-31-2013 10:31 PM

With 2" springs, 1" MML, pushing the upper rear control arm mounting locations back slightly, and lengthening the lower control arms, I was able to match the transfer case out put and pinion shaft angles with about 1/2" transfer case drop.

Patrick H 03-31-2013 10:33 PM

Quote:

Originally Posted by WVU Mountainman (Post 3577551)
Which would give me the most adjustment? Uppers or lowers?

Here's the issue with that- you would need shorter than stock upper control arms. I was not able to find any aftermarket adjustables that would adjust shorter than stock. You could, however, buy some adjustable uppers, and shorten the control arm a bit by cutting a little off of one end.

Patrick H 03-31-2013 10:34 PM

Quote:

Originally Posted by TJspeed (Post 3577468)
Between the mml and 1" tc drop you should be close to stock.

Stock what?

WVU Mountainman 03-31-2013 10:40 PM

Quote:

Originally Posted by Patrick H (Post 3577565)

Here's the issue with that- you would need shorter than stock upper control arms. I was not able to find any aftermarket adjustables that would adjust shorter than stock. You could, however, buy some adjustable uppers, and shorten the control arm a bit by cutting a little off of one end.

Thanks Patrick. I'm horrible at visualizing how this works. So shortening the upper arms will rotate the pinion angle down?

Patrick H 03-31-2013 10:41 PM

Quote:

Originally Posted by WVU Mountainman (Post 3577593)
Thanks Patrick. I'm horrible at visualizing how this works. So shortening the upper arms will rotate the pinion angle down?

Yes. Same reason you need to lengthen them when installing a SYE, when you need to push the pinion up.

WVU Mountainman 03-31-2013 10:46 PM

Quote:

Originally Posted by Patrick H (Post 3577599)

Yes. Same reason you need to lengthen them when installing a SYE, when you need to push the pinion up.

Thank you. If I shorten the uppers to I have to in turn lengthen the lowers?

Patrick H 03-31-2013 10:49 PM

Quote:

Originally Posted by WVU Mountainman (Post 3577614)
Thank you. If I shorten the uppers to I have to in turn lengthen the lowers?

No, you don't have to do both, unless you're concerned with maintaining wheel base. It should take little enough adjustment that wheel base is a non-issue, especially since lifting a Jeep with stock length control arms actually shortens the wheel base slightly anyway.

WVU Mountainman 03-31-2013 10:53 PM

Thanks man. Going off memory but I called currie at one point. There adjustable arms were 13" which is 1/4 shorter than stock. do you think would this provide enough adjustment

GoldenSahara00 03-31-2013 10:53 PM

A good question is why is your pinion that high to begin with? Are your stock arms bent in some way?

Patrick H 03-31-2013 10:55 PM

You'll have to modify (cut shorter) upper adjustables to make them shorter than stock.

Since the mounting points for the lower arms are closer to the axle centerline than the uppers, it would take less adjustment of the lower arms than it would the upper arms to achieve the same change in pinion angle. One of the reasons I chose to lengthen the lowers, rather than having to modify (cut) adjustable uppers to lower my pinion angle. I consider this all temporary until I can get the SYE installed.

Patrick H 03-31-2013 10:56 PM

Quote:

Originally Posted by GoldenSahara00 (Post 3577653)
A good question is why is your pinion that high to begin with? Are your stock arms bent in some way?

The higher the Jeep is raised, the higher the pinion angle gets.

Patrick H 03-31-2013 10:57 PM

Quote:

Originally Posted by WVU Mountainman (Post 3577648)
Thanks man. Going off memory but I called currie at one point. There adjustable arms were 13" which is 1/4 shorter than stock. do you think would this provide enough adjustment

Not sure. Like I said, it would take more adjustment of the upper arms than it would the lower arms to achieve the same change in pinion angle. IIRC, my lowers are close to 1/4" longer than stock.

WVU Mountainman 03-31-2013 10:57 PM

Quote:

Originally Posted by GoldenSahara00 (Post 3577653)
A good question is why is your pinion that high to begin with? Are your stock arms bent in some way?

No not bent

GoldenSahara00 03-31-2013 10:58 PM

Quote:

Originally Posted by Patrick H (Post 3577661)

The higher the Jeep is raised, the higher the pinion angle gets.

You don't say? However with 2 inches of lift that seems to be an excessive amount of pinion angle. Wouldn't it be a waste to spend a few hundred on arms and time modifying uppers when the cause could be bent stock control arms which can be replaced extremely cheaply?

It's sometimes worth asking questions and not throwing expensive answers out before investigating the issue completely.

Patrick H 03-31-2013 11:01 PM

Quote:

Originally Posted by GoldenSahara00 (Post 3577674)
You don't say? However with 2 inches of lift that seems to be an excessive amount of pinion angle. Wouldn't it be a waste to spend a few hundred on arms and time modifying uppers when the cause could be bent stock control arms which can be replaced extremely cheaply?

It's sometimes worth asking questions and not throwing expensive answers out before investigating the issue completely.

I went through the exact same thing he is. My arms aren't bent either. I consider my exact experience as good or better than "investigating".

Patrick H 03-31-2013 11:03 PM

And I installed adjustable lowers, and didn't modify any uppers. I'm going to want adjustable control arms anyway, so I didn't see it as wasting money.

GoldenSahara00 03-31-2013 11:04 PM

Quote:

Originally Posted by Patrick H (Post 3577680)

I went through the exact same thing he is. My arms aren't bent either. I consider my exact experience as good or better than "investigating".

That's great. Ill leave this to you then since you know everything :thumb:


Quote:

Originally Posted by Patrick H (Post 3577694)
And I installed adjustable lowers, and didn't modify any uppers. I'm going to want adjustable control arms anyway, so I didn't see it as wasting money.

That's good for people like you who just buy expensive parts and bolt them on.

Patrick H 03-31-2013 11:05 PM

Quote:

Originally Posted by GoldenSahara00 (Post 3577698)
That's great. Ill leave this to you then since you know everything :thumb:

Cool, thanks.

cuder 03-31-2013 11:12 PM

Where are you measuring the planes? Are you using the u-joint caps on the TC yoke and the machined flat on the back of the axle?

WVU Mountainman 03-31-2013 11:18 PM

Quote:

Originally Posted by cuder (Post 3577732)
Where are you measuring the planes? Are you using the u-joint caps on the TC yoke and the machined flat on the back of the axle?

I've done multiple ways but am not sure of the best. You can visually see they do not match.

Patrick H 03-31-2013 11:22 PM

I prefer using the machined flats on the back, but the u-joint cap/ socket works as well.


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