YJ Rough Country 2.5 inch lift questions

joe b

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Mar 13, 2023
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Harrisonville mo
Hello I'm new to this forum and new to wrangler yj.
My wife and I just purchased our first yj.
Just installed a rough country lift and the front seems to be right but the rear spring shackels are not sitting vertical like the front.
The rear shackels are angled toward the front of jeep and the leaf springs seem to short.
The jeep is sitting alot higher in the rear also.
Has anyone ever ran into this issue.
Appreciate any and all help. Thank you
 
Common, their springs are pretty short. Not much you can do about it except maybe ask RC for new springs. The RC springs I had put the shackles exactly vertical front and rear. Ideally, the rear shackles should be towards the rear of the Jeep and the fronts should be towards the front.

Sitting higher in the rear is not normal. My jeep was about perfectly level on RC 2.5". maybe you need to loosen the shackle bolts and retorque. If you tightened them in the air, they could have the spring stuck in a non relaxed state which would keep them from flexing out to normal height once on the ground.

There are various reasons why I don't like to recommend RC suspension....the end result is just not that great. Been there, done that. Unfortunately the good stuff is a lot more expensive.
 
All the hardware is still only snug and jeep is sitting on the ground.
I have not torqued anything yet.

I guess you do get what you pay for
 
Common, their springs are pretty short. Not much you can do about it except maybe ask RC for new springs. The RC springs I had put the shackles exactly vertical front and rear. Ideally, the rear shackles should be towards the rear of the Jeep and the fronts should be towards the front.

Sitting higher in the rear is not normal. My jeep was about perfectly level on RC 2.5". maybe you need to loosen the shackle bolts and retorque. If you tightened them in the air, they could have the spring stuck in a non relaxed state which would keep them from flexing out to normal height once on the ground.

There are various reasons why I don't like to recommend RC suspension....the end result is just not that great. Been there, done that. Unfortunately the good stuff is a lot more expensive.
Would boomerang shackels cure this?
 
Would boomerang shackels cure this?
No. Boomerang shackles don't change the geometry.
The geometry is calculated from the perch bolt to the spring eye bolt. The shape of the shackle does not affect this angle.
20230313_162846.jpg
 
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Okay.
I do have the rear bumper off and the gas tank is out right now.
I added a picture of the rear shackel.
Is this a problem or will it settle after installing gas tank and driving jeep?

20230313_183220.jpg
 
The problem with that is if you were off roading the shackle can actually flip over and be wedged up against the frame. This leaves you with rigid suspension, and to undo it you either have to use a long pry bar to flip it back or try dropping that wheel into a dip or hole and hope it reverses itself back to normal. I went thru this numerous times with a POS and I do mean POS lift kit from Pro Comp on one of my CJ's. If it was mine Id be removing at least one of the rear leafs from the pack until it levels out and pushes that shackle back to at minimum vertical or tipped back as it should be. I will admit I also did this on my 91 with its RE 2.5 kit. Been like this for years now and sits perfect and rides good.
 
The problem with that is if you were off roading the shackle can actually flip over and be wedged up against the frame. This leaves you with rigid suspension, and to undo it you either have to use a long pry bar to flip it back or try dropping that wheel into a dip or hole and hope it reverses itself back to normal. I went thru this numerous times with a POS and I do mean POS lift kit from Pro Comp on one of my CJ's. If it was mine Id be removing at least one of the rear leafs from the pack until it levels out and pushes that shackle back to at minimum vertical or tipped back as it should be. I will admit I also did this on my 91 with its RE 2.5 kit. Been like this for years now and sits perfect and rides good.
You have a 2.5 inch lift?.
Did you have to install a drop pitman arm and or transfer case drop, engine mount lift?
 
You have a 2.5 inch lift?.
Did you have to install a drop pitman arm and or transfer case drop, engine mount lift?
You don't "have" to install a drop pitman, but it's better for the steering.

You don't need a MML, although the transfer case drop or SYE is a good way to go. Rough Country ships retarded thick shims on the rear springs, and those are only well suited for a slip yoke eliminator and aftermarket driveshaft. If not wanting to do the SYE and aftermarket driveshaft, then a RC transfer case drop and changing the shims to about 2 degrees thick is the best way to go to do that.
 
Yes, I have a RE 2.5 in my 91. I am running Rancho 5000X shocks, a 1" T case drop and 1 less rear leaf. I also have a drop arm off a ZJ I believe, which is what many aftermarket places sell if im not mistaken. I had bump steer that bugged me and the arm fixed 90% of it. Ive tossed around the engine lift but never got around to it. I had yanked the T case drop once for shits and giggles and it was not good. Looks like you have a really nice YJ to start with. Just keep in mind one fix or mod creates one or more short commings. J ust E mpty E very P ocket.
 
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Witch leaf did you remove from the rear spring pack.?
So I should remove a leaf and replace the rough country shim with a 2 degree shim then a 1 inch t case drop?.

My wife and I are planning a trip out to Colorado this year and I'm really just looking for a good ride.
I'm planning on 31 Inch tires.
I'm not sure what gear ratio I have yet but soon I am going to service both different, t case and trans when I replace the clutch and hydraulics
 
It was one of the lower/shorter ones but not the very shortest. If you have a 4 banger you have 4.11 gears. if you have a 4.0 you can check the rear diff and see what the tag says.
 
Witch leaf did you remove from the rear spring pack.?
So I should remove a leaf and replace the rough country shim with a 2 degree shim then a 1 inch t case drop?.

My wife and I are planning a trip out to Colorado this year and I'm really just looking for a good ride.
I'm planning on 31 Inch tires.
I'm not sure what gear ratio I have yet but soon I am going to service both different, t case and trans when I replace the clutch and hydraulics
The transfer case drop lowers the transfer case output which changes the angle. It’s roughly a 2-3° change. The pinion needs to come up about that much to keep things parallel. If you want to be scientific about it, put an angle finder on the tcase before and after and buy leaf springs shims in the same amount that the tcase output changes.

For gear ratios, with your 4.0 you have either 3.07 or 3.55. Many manuals were 3.07, a few were 3.55. My 94 was 3.55, it was a base model SE and didn’t appear to have anything special (no tow hitch or anything) but it got the lucky gearing. With 31’s, both stock gearing options suck. I was frequently downshifting with 3.55 and 31’s from 5th gear. 3.07 would really suck on 31’s and even sucks on the stock 27’s.
 
No. Boomerang shackles don't change the geometry.
The geometry is calculated from the perch bolt to the spring eye bolt. The shape of the shackle does not affect this angle.
View attachment 121103
No. Boomerang shackles don't change the geometry.
The geometry is calculated from the perch bolt to the spring eye bolt. The shape of the shackle does not affect this angle.
View attachment 121103
I totally agree. As a life time engineer, machinist and someone that built lots if parts for my Jeep, I see no purpose for a “Boomerang” shape shackles unless you want to be different. Nothing on them changes the actual purpose of them. All that they do is connect the end of the leaf springs to the frame. WhT ever distance they are they will do just that. I don’t care if they are in the shape of a disk, a triangle or like someone mentioned here, the shape of a thunder bolt. All they do is maintain that distance between two holes. Nothing more, nothing less. I like the idea of greasable screws but that is it.. I am in process of making me some shackles right now out of 3/8 stainless steel. Probably not different than the original shape of the shackles ( unless I make them this shape: 💲… LOL
 
I totally agree. As a life time engineer, machinist and someone that built lots if parts for my Jeep, I see no purpose for a “Boomerang” shape shackles unless you want to be different. Nothing on them changes the actual purpose of them. All that they do is connect the end of the leaf springs to the frame. WhT ever distance they are they will do just that. I don’t care if they are in the shape of a disk, a triangle or like someone mentioned here, the shape of a thunder bolt. All they do is maintain that distance between two holes. Nothing more, nothing less. I like the idea of greasable screws but that is it.. I am in process of making me some shackles right now out of 3/8 stainless steel. Probably not different than the original shape of the shackles ( unless I make them this shape: 💲… LOL
The true purpose of boomerang shackles is to prevent shackle inversion which more often than not will invert the spring. Otherwise, the boomerangs serve very little to no purpose.
 
The true purpose of boomerang shackles is to prevent shackle inversion which more often than not will invert the spring. Otherwise, the boomerangs serve very little to no purpose.
Thanks for the input. I have my YJ for almost 17 years now and never had a spring inverted… That being said, I am not arguing with that prednisone. I am sure others have had that happened to them.. I happen to live in Florida and we don’t have rough enough terrain to have that happen to us.. LOL.
 
Thanks for the input. I have my YJ for almost 17 years now and never had a spring inverted… That being said, I am not arguing with that prednisone. I am sure others have had that happened to them.. I happen to live in Florida and we don’t have rough enough terrain to have that happen to us.. LOL.
Lol - yeah I haven’t either. I have definitely seen others post that happening, seems to be when they get one wheel really stuffed which droops the opposite wheel, then they bump over an obstacle in that position which kicks the spring back beyond where it should be. They are really only beneficial for a small crowd.

The only reason I ever ran them was because there aren’t many options for shackles that I like.