Savvy Mid Arm Axle Side Bracket Positions Needed

carrotman

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Hi All,

Currently undergoing an axle swap and need to know where to mount the three link brackets on the front axle for the Savvy mid arm. Are there any measurements to go off of? Should the top link be centered on the axle vertically and some specific distance to the driver side of the axle center point? How far up does it go? IIRC the LCA brackets are just kept at the stock TJ locations - Would there be any detriment to moving them upward to keep the brackets out of the rocks? Would I need to compensate this change by raising the upper link too, for maintaining link separation, or is there more to it than that? Should I just not change anything? I'm guessing uptravel would become an issue if the uppers were moved up further, and would be a bigger deal than scratching my LCA brackets. Same questions for the rear, I'll be tackling that next.

Any help greatly appreciated! Apologies if this has been covered before, I couldn't find anything.
 
Here are the rough draft install instructions
 

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Here are the rough draft install instructions

Appreciated, but that doesn't tell me where to place the front upper axle link. Rear is a little easier since it indexes off the diff cover, but the front not so much. Forgot to mention that I can't use the front truss because 1. my center section is too wide, and 2. I already cut it up when installing it on the last axle. I'll need to make my own truss this time.
 
Appreciated, but that doesn't tell me where to place the front upper axle link. Rear is a little easier since it indexes off the diff cover, but the front not so much. Forgot to mention that I can't use the front truss because 1. my center section is too wide, and 2. I already cut it up when installing it on the last axle. I'll need to make my own truss this time.

When I asked Blaine I was TOLD where it fits. I had to shove mine as far to the drivers side as possible due to starter clearance but I have a V-8 in mine.

I was pretty sure it did give a general idea where the upper went using the cut off upper mount as reference?
 
Hi All,

Currently undergoing an axle swap and need to know where to mount the three link brackets on the front axle for the Savvy mid arm. Are there any measurements to go off of? Should the top link be centered on the axle vertically and some specific distance to the driver side of the axle center point? How far up does it go?

The upper arm if I remember correctly is just there to set the pinion angle & keep the axle from rotating. Of course all this maybe incorrect and others may jump in and correct this.

IIRC the LCA brackets are just kept at the stock TJ locations - Would there be any detriment to moving them upward to keep the brackets out of the rocks? Would I need to compensate this change by raising the upper link too, for maintaining link separation, or is there more to it than that? Should I just not change anything?

You do not want to mess with the placement of the brackets or their design. They are made to fit and work in their set place and based on the design are not a problem for hanging up in the rocks.

I'm guessing uptravel would become an issue if the uppers were moved up further, and would be a bigger deal than scratching my LCA brackets. Same questions for the rear, I'll be tackling that next.

Any help greatly appreciated! Apologies if this has been covered before, I couldn't find anything.

If you tried to raise the upper mounts as you suggested you'd run into up travel issues. Both in the front & for sure in the rear. You'll have enough issues with the rear & up travel without messing with the upper links.


And BTW yes I have the midarm on my TJ also.

What axles are you using? This would help a little. Mine was totally custom with a HP44 out of a Ford for the front & a TeraLow CRD60 rear so I used my own trusses on each axle.
 
Appreciated, but that doesn't tell me where to place the front upper axle link. Rear is a little easier since it indexes off the diff cover, but the front not so much. Forgot to mention that I can't use the front truss because 1. my center section is too wide, and 2. I already cut it up when installing it on the last axle. I'll need to make my own truss this time.

Are you using a TJ axle or something else in the front. The Savvy truss has you cut the existing mount on top of the diff. The CA bracket is just to the passenger side of that old mount.
 
Axles are both 44s. Rear is just a factory JK axle, front going in is an ECGS 489 housing with the 3" tubes, but at JK width. Axle coming out is a JK30. Here's the build thread I started recently in case it provides any missing details: https://wranglertjforum.com/threads/doing-it-the-hard-way.67710/

Here's a pic of the 30 and why I can't re-use the Savvy truss:

IMG_4262.jpeg


I could just copy the bracket locations from before, but I'm not entirely convinced I did it right the first time.

Regarding the upper link location, surely there was some science to it, or why wouldn't the kit just use the cast-in UCA mount? It's only like an inch away from it and it has you cut the thing off.
 
The front is a parallel 3 link. Meaning the vertical separation on the frame side is the same as the axle side. Because the arms are also the same length, the caster is preserved throughout the suspension travel. Assuming you have the Savvy frame mounts, use that to determine the separation on the axle. From there, the upper link needs to clear whatever is nearby in it's travel path. Position it side to side where it doesn't hit stuff.
 
The front is a parallel 3 link. Meaning the vertical separation on the frame side is the same as the axle side. Because the arms are also the same length, the caster is preserved throughout the suspension travel. Assuming you have the Savvy frame mounts, use that to determine the separation on the axle. From there, the upper link needs to clear whatever is nearby in it's travel path. Position it side to side where it doesn't hit stuff.

Perfect, thanks. Not urgent, but what about the rear?

Assuming the upper had all the room in the world, there would be no other issue with moving lowers higher up and maintaining that same separation? I’m pretty sure there isn’t any room but just as a thought exercise.
 
Perfect, thanks. Not urgent, but what about the rear?

Assuming the upper had all the room in the world, there would be no other issue with moving lowers higher up and maintaining that same separation? I’m pretty sure there isn’t any room but just as a thought exercise.

You aren't going to have any room for upper travel. You already have to dimple the tub where the arms hit & your upper links will hit the tub or crossmember.
 
Perfect, thanks. Not urgent, but what about the rear?

Assuming the upper had all the room in the world, there would be no other issue with moving lowers higher up and maintaining that same separation? I’m pretty sure there isn’t any room but just as a thought exercise.

All I know about the rear is that with Currie 60s, the goal is to keep the upper mounts as low and tight to the top of the housing as possible, so as to not reduce up travel. You don't want to raise the lowers because that would increase the stress on the upper mounts
 
Thanks again @jjvw for the realization that it is a parallel 3 link with equal length links. I did some measuring with lasers to see where the bracket was at, then measured my old axle and discovered it was indeed off by a little bit. On the axle, my vertical link separation is about .25" more than it should have been, and the front to back link separation is about .625" short, within some margin of error in my measurements of course. I wonder if this small error was perceptible at all in regards to how the suspension cycled - I've never driven a correctly done one.
I'm guessing I put the lower control arm brackets a bit too low/forward on the tube, but at least I know better this time around. The fact that they are lower than they should have been in the first place is also probably why I was inclined to raise them up more.

IMG_4330.jpeg
 
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Also, I drew up the front suspension geometry to the best of my ability in CAD, and from what I can tell, at least for these parallel links, the front to back position of the brackets on the axle has no impact to the geometry itself (assuming correct spacing between them is maintained), and the only real consideration for where to put them is how well it packages in the vehicle. If anyone knows this is false and can tell me why, please let me know.
 
Also, I drew up the front suspension geometry to the best of my ability in CAD, and from what I can tell, at least for these parallel links, the front to back position of the brackets on the axle has no impact to the geometry itself (assuming correct spacing between them is maintained), and the only real consideration for where to put them is how well it packages in the vehicle. If anyone knows this is false and can tell me why, please let me know.

Your goal is to preserve caster throughout the suspension travel and make sure the upper arm doesn't crash into other things.
 
Also, I drew up the front suspension geometry to the best of my ability in CAD, and from what I can tell, at least for these parallel links, the front to back position of the brackets on the axle has no impact to the geometry itself (assuming correct spacing between them is maintained), and the only real consideration for where to put them is how well it packages in the vehicle. If anyone knows this is false and can tell me why, please let me know.

Keep in mind the links only have so much adjustability. You want to match tj axle mount front to back locations as close as you can so caster adjustment remains usable.

A scrap tj/xj/zj axle may help you mock up lower and upper locations.then with intended starting arm lengths,measure pinion angle/caster. you can move the top mount to the jk axle and slide it forward/back until you duplicate that angle?

Food for thought anyway
 
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Iron Rock off-road sells a pair of lowers that are a thicker version of stock.

Another reason Artec mounts are dumb is that they create a near vertical face to push against the rocks, unlike stock which is ramped.
 
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I was checking the hangy downy bits thread - Is Blaine's 2" weld washer trick necessary on an aftermarket bracket already 1/4" thick or is that only really necessary on a stock bracket? Also, why only a 2" washer? Isn't a JJ about 2.625" diameter and would therefore hang lower?
 
If anyone has accurate measurements of the position of a factory TJ front axle's LCA mounts, I'd greatly appreciate it. Several hours of googling has turned up nothing useful...
 
I found some drawings within Clayton's installation instructions for their version of stock TJ LCA brackets (attached). Threw screenshots of their diagrams up in Onshape and made some dimensions there. In case it helps anyone on the internet, I've come up with this:
  • Brackets point inwards towards the frame mounts at 5°
  • Width wise, the center of the brackets should be 32.75" apart from each other, or 16.375" from center of axle, measured at the bolt.
  • From the left side view, a straight line from the center of the axle tube to the center of the bolt on the outboard edge of the bracket is 3.85". From the OD of the axle tube assuming 2.5" diameter would be 2.6"
  • With the pinion/diff cover face at 90° or perpendicular to the ground, the line between the LCA bolt and the center of the axle is positioned about 138° clockwise
  • Assuming that last angle is accurate, the center of the outboard bolt hole should be about 2.85" below axle centerline and 2.59" behind.
I needed all these specific measurements because I'm making my own brackets. If you aren't but have a bare housing with no reference brackets, I'd maybe get the Clayton brackets since they are the only manufacturer I found that gives actual dimensions of where to put the damn things instead of "1/4" away from the spring buckets" or something equally stupid which does you no good if you have a bare axle tube.

Take those measurements with a grain of salt too though, Clayton's drawings show a 13.7° pinion to inner C offset which seemed weird, thought stock was only about 6° but maybe I'm thinking of JK axles.

I sent an email to Savvy this morning to confirm the upper mount position but haven't heard back yet, will update if they reply.
 

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  • Clayton TJ Front LCA Drawings.PDF
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