How much of the Johnny Joint shank can be showing on Savvy control arms?

[Chris]

I got all my rear Savvy control arms on today, as well as my Tom Wood driveshaft. Now that I'm adjusting the upper arms to bring the pinion angle up, I'm noticing that I'm having to adjust the upper arms to be really long, which is therefore causing a lot of the shank on the Johnny Joints to show.

I attribute this to the fact that the tummy tuck put the transfer case so far up there that the pinion angle is much steeper than it would be if I was running the stock skid plate (right?).

Either way, my Savvy arms didn't come with directions, so I'm not sure what the rule of thumb is as to how much shank can be showing on the arms after the jam nut.

I'm also noticing that changing the angle of my rear pinion is causing the rear track bar to get so close to my Rokmen gas tank skid, that it looks like it's going to contact it.

 

[ac_]

Can you equalize some with the lowers at all?

 

[Chris]

Can you equalize some with the lowers at all?

Well, I can't extend the lowers anymore (right now they are at 16"). If I move them out and further without extending the uppers, it's going to cause the pinion angle to drop (right?), which won't work since the angle is almost perfect as we speak.

If I bring the lowers in more (let's say down to something like 15.5"), I could then reduce the length of the uppers I believe, though I'm not sure if it would be anything substantial.

 

[ac_]

Well, I can't extend the lowers anymore (right now they are at 16"). If I move them out and further without extending the uppers, it's going to cause the pinion angle to drop (right?), which won't work since the angle is almost perfect as we speak.

If I bring the lowers in more (let's say down to something like 15.5"), I could then reduce the length of the uppers I believe, though I'm not sure if it would be anything substantial.

IN my head I was thinking the opposite if you are extending your uppers can you shorten your lowers to bring the pinion up?

 

[Chris]

IN my head I was thinking the opposite if you are extending your uppers can you shorten your lowers to bring the pinion up?

Yeah, that makes sense. But I don't want to extend the uppers too much, because I'm not sure how much of the shank is allowed to be showing. Right now there's quite a bit of it showing.

But I think I see what you're saying. Shorten my lowers a little bit which would bring the pinion angle up even further, but then I can also shorten my uppers as to bring the pinion angle back down to where it should be.

 

[ac_]

Yes that is my suggestion, but I don't have any experience with the Savvy stuff in particular. So I don't know if that will work or not. but it is something to try in my opinion.

 

[Chris]

Yeah, in terms of the rear track bar contacting the gas tank skid, that happened once I rotated the pinion angle up far enough that it caused the track bar to contact. This could be solved I think by shortening the lowers, and then reducing the length of the uppers as well. So basically shortening the wheelbase from what it current is. My lowers as they sit current are 16".

 

[ac_]

ya also I think your uppers will be extended more than usual too because of the tummy tuck because that will bring your output shaft quite a bit higher than usual, so I am betting it is pretty normal to have more threads than usual. But since they don't have different options and tummy tucks are common, I would imagine it is going to be ok.

I would adjust it where it is perfect or your perfect, then send pictures to Savvy, and have them double check it for you if you are still nervous.

 

[Jorge Bolivar]

@Chris
Mines end up a little over half of the JJ tread out the jam nut. Following @ac_ suggestion, extend the lower control arms to the half of the JJ tread length, then you have will have some room to close the lowers if uppers seem too extended. on ac_ words, equalize the space.

Depending on your track bar, you may need the bracket that angle the trackbar at the diff toward the tranny. I do have the JKS-OGS160 on my TJ.

Edited 20180503 - JBA- Typo
Jamb to Jam

 

[Chris]

@Chris
Mines end up a little over half of the JJ tread out the jamb nut. Following @ac_ suggestion, extend the lower control arms to the half of the JJ tread length, then you have will have some room to close the lowers if uppers seem too extended. on ac_ words, equalize the space.

Depending on your track bar, you may need the bracket that angle the trackbar at the diff toward the tranny. I do have the JKS-OGS160 on my TJ.

I also have the JKS-OGS160 track bar bracket as well. I'll give this a try though. I think I can figure it out, I just wasn't sure what the limit is for the amount of shank showing on the Johnny Joint before it becomes an issue.

 

[jjvw]

I also have the JKS-OGS160 track bar bracket as well. I'll give this a try though. I think I can figure it out, I just wasn't sure what the limit is for the amount of shank showing on the Johnny Joint before it becomes an issue.

I thought there was a rule of thumb about the minimum amount of inserted shank. Something like the minimum inserted thread should be no less than x times the diameter of the shank.

I also recall that adding an additional jam nut will support the exposed shank.

 

[xxdabroxx]

You also want to make sure you are contacting the bump stops correctly. Don’t try and center the wheel in the opening. That should keep you in pretty reasonable lengths I’d think. But the tt may have some additional effect on that.

 

[Chris]

I thought there was a rule of thumb about the minimum amount of inserted shank. Something like the minimum inserted thread should be no less than x times the diameter of the shank.

I also recall that adding an additional jam nut will support the exposed shank.

Yeah, that’s what I’m trying to figure out here.

You also want to make sure you are contacting the bump stops correctly. Don’t try and center the wheel in the opening. That should keep you in pretty reasonable lengths I’d think. But the tt may have some additional effect on that.

Yep, I’m not trying to center the wheel in the opening. I’m focused on the bump stops lining up, the track bar clearing, and the angle of the pinion.

 

[Jorge Bolivar]

I also have the JKS-OGS160 track bar bracket as well. I'll give this a try though. I think I can figure it out, I just wasn't sure what the limit is for the amount of shank showing on the Johnny Joint before it becomes an issue.

This is the part that vendors no talk about it, Trial and error x 10 until you feel comfortable with your set up. I will like to said that 1/3 of the rod inside the nut will be Ok, but again is about how comfortable you feel with it. No worry too much, you will soon found your sweet spot.

 

[jjvw]

https://fieldfastener.com/2013/04/23/rules-of-thumb-for-fastening-and-joining/

The length of thread engagement in a steel nut member should be equal to or greater than one full diameter of the bolt and be of comparable strength (i.e. if the screw is ¼” diameter, the thread engagement needs to be a minimum of ¼”).

 

[TJDaveX]

I am not sure if you have the dbl adjustable arms. But, I took some pics of my Savvy aluminum dbl adjustable arms for reference. I am also running a standard SYE and UCF tummy tuck.
I have my lowers adjusted pretty far in. And the uppers have around an inch showing.
Also looks like I have a leak to track down and some cleaning to do!

Uppers

Lowers

Looking at my Jeep sitting on level ground, my rear wheel is not shoved towards the door as I have seen some lifted Jeeps.
Hope this helps.

 

[Chris]

I am not sure if you have the dbl adjustable arms. But, I took some pics of my Savvy aluminum dbl adjustable arms for reference. I am also running a standard SYE and UCF tummy tuck.
I have my lowers adjusted pretty far in. And the uppers have around an inch showing.
Also looks like I have a leak to track down and some cleaning to do!

Uppers

View attachment 40181

View attachment 40182

Lowers

View attachment 40183

View attachment 40184

Looking at my Jeep sitting on level ground, my rear wheel is not shoved towards the door as I have seen some lifted Jeeps.
Hope this helps.

This is exactly what mine is looking like. The uppers have about an inch of thread showing after the jam nut, and the lowers are almost all the way in.

It’s the excessively steep angle of the pinion caused by the tummy tuck that’s the reason for this I think.

 

[Mike_H]

How long is the threaded? My rule of thumb is 2x engagement per diameter... So, if it's a 1/2" bolt, 1" of engagement. That is a very cautious rule of thumb. A jamb nut will also help stabilize the joint.

To be perfectly clear though... I'm not a suspension designer, just a guy who knows a fair amount about threaded joints, in general.

 

[Chris]

How long is the threaded? My rule of thumb is 2x engagement per diameter... So, if it's a 1/2" bolt, 1" of engagement. That is a very cautious rule of thumb. A jamb nut will also help stabilize the joint.

To be perfectly clear though... I'm not a suspension designer, just a guy who knows a fair amount about threaded joints, in general.

I believe these Johnny Joints have a 2.5” threaded shank. When I measure the amount of thread showing after the jam nut, it’s around 1.25”.

 

[Jorge Bolivar]

I believe these Johnny Joints have a 2.5” threaded shank. When I measure the amount of thread showing after the jam nut, it’s around 1.25”.

That should be fine.
My Core 4x4 JJ are welded into a 5.5" of threaded rod. Yours are double adjustable, so I expect they are designed to push even out that will be 2.5" + 2.5".
Are the tube is threaded all the way down or just a section?