Jeep TJ rear wheelbase stretch with existing Rubicon Express long arm kit

P

paulrobbyn

New Member
Joined
Oct 15, 2021
Messages
5
Location
Sonoma County
Hi all
I have searched for this and found some things here and there, but really old posts with broken links. So hopefully this sticks. I have a 98 TJ and have owned since 2001. Done all the work since it was stock. Right now it has a built Waggy front axle, stock rear Dana 44 with just chrome molly shafts. RE 4.5" long arm with metalcloak arms and 35's. I decided to finally work on the rear and do a stretch. So did some research and started ordering parts. So far I have the GR stretch tank and the stretch fenders. Ordered and waiting on my Carbon offroad Dana 60 with bridge for triangulation. I plan on using an old pair of Metalcloak LJ lower control arms after cutting them down. I guess I will have to build new upper. Was thinking of calling barnes for those. The one thing I am not totally sure of is coilover selection. I will probably go with Kings, but not sure how to size them and select coil spring rates. I am assuming I do not do that till I have the axle under to measure correct? How do I select spring rates? The axle is coming bare (no track bar of spring mounts) to allow me to weld on the coil tabs.
Thanks in advance for any advice. Really looking forward to this upgrade after two decades of wheeling this jeep on the con and surrounding Sierra trails. Ive gotten quite use to lifting the front end. ;-)
IMG_6539.jpg










a
IMG_6971.jpg
 
  • Like
Reactions: WSS, JMT, SvtLdr and 2 others
paulrobbyn said:
Hi all
I have searched for this and found some things here and there, but really old posts with broken links. So hopefully this sticks. I have a 98 TJ and have owned since 2001. Done all the work since it was stock. Right now it has a built Waggy front axle, stock rear Dana 44 with just chrome molly shafts. RE 4.5" long arm with metalcloak arms and 35's. I decided to finally work on the rear and do a stretch. So did some research and started ordering parts. So far I have the GR stretch tank and the stretch fenders. Ordered and waiting on my Carbon offroad Dana 60 with bridge for triangulation. I plan on using an old pair of Metalcloak LJ lower control arms after cutting them down. I guess I will have to build new upper. Was thinking of calling barnes for those. The one thing I am not totally sure of is coilover selection. I will probably go with Kings, but not sure how to size them and select coil spring rates. I am assuming I do not do that till I have the axle under to measure correct? How do I select spring rates? The axle is coming bare (no track bar of spring mounts) to allow me to weld on the coil tabs.
Thanks in advance for any advice. Really looking forward to this upgrade after two decades of wheeling this jeep on the con and surrounding Sierra trails. Ive gotten quite use to lifting the front end. ;-)
View attachment 283882









a View attachment 283881
Click to expand...
Give Paul a call at Elite Offroad in Birmingham Alabama- He is pretty knowledgeable on Coil overs and stretches.

You can find them with a Google search.
 
  • Like
Reactions: John Cooper
paulrobbyn said:
64
Click to expand...
It will be a challenge to fit even a 2” coilover in the back at that width if you have any kind of articulation. It can be done, but it will be crazy tight. Depending on your backspacing you may have to resort to using a spacer.
 
NashvilleTJ said:
It will be a challenge to fit even a 2” coilover in the back at that width if you have any kind of articulation. It can be done, but it will be crazy tight. Depending on your backspacing you may have to resort to using a spacer.
Click to expand...
Stock Rubicon axles. Fox 12" 2.0 coil overs. 35's with 4"ish of back spacing. Tight, but very doable if you are patient.
DSC_4829.JPG
 
  • Like
  • Love
Reactions: Tob, Therbytj, L J and 6 others
paulrobbyn said:
Thanks. So I take it keep coils and out boarding shocks isn’t much better??? I can still go that route too and use a spring relocation kit.
Click to expand...
How much travel are you looking for? 11" front, 12" rear split 50/50 is common.
 
That I don’t know yet. Right now I just have Metalcloak’s 4.5 springs front and rear with the RE belly and MC long arms. I’m thinking 12”
 
paulrobbyn said:
That I don’t know yet. Right now I just have Metalcloak’s 4.5 springs front and rear with the RE belly and MC long arms. I’m thinking 12”
Click to expand...
If that is what you are sticking with, you'll have to figure out the available travels from ride height, including the useable spring travels to support the shocks.

The desirable shock travel bias is about 50/50 travel from ride height.

Be aware that Metalcloak rear coils reach bind sooner than most anything else in the 4-5" range.

Stretching a bolt on long arm is a whole other mess that I'm not at all sure how to do without a bunch of weird compromises.

Mine is built around Currie stuff and the Savvy mid arm. The rear outboard with 12s is fairly straightforward. Getting front 12s in without highlines is a huge amount of work and only slightly easier with. 11s are significantly easier to package.

I'm seriously considering a 5-6" stretch now that I learned how to do a fuel cell in a manner I like. When that happens, the frame will be cut right in front of the rear control arms so that the entire arch can be moved backwards. This keeps the entirety of the rear suspension intact.
 
  • Like
Reactions: D M
jjvw said:
If that is what you are sticking with, you'll have to figure out the available travels from ride height, including the useable spring travels to support the shocks.

The desirable shock travel bias is about 50/50 travel from ride height.

Be aware that Metalcloak rear coils reach bind sooner than most anything else in the 4-5" range.

Stretching a bolt on long arm is a whole other mess that I'm not at all sure how to do without a bunch of weird compromises.

Mine is built around Currie stuff and the Savvy mid arm. The rear outboard with 12s is fairly straightforward. Getting front 12s in without highlines is a huge amount of work and only slightly easier with. 11s are significantly easier to package.

I'm seriously considering a 5-6" stretch now that I learned how to do a fuel cell in a manner I like. When that happens, the frame will be cut right in front of the rear control arms so that the entire arch can be moved backwards. This keeps the entirety of the rear suspension intact.
Click to expand...
DSC_6041.JPG
DSC_6045.JPG
 
  • Haha
Reactions: jjvw
OP, you mention in the first post about getting used to the front end lifting, is this from the RE long arm geometry? I have the same RE LA and have what you describe often. It is not really squat by link standards.
 
WSS said:
OP, you mention in the first post about getting used to the front end lifting, is this from the RE long arm geometry? I have the same RE LA and have what you describe often. It is not really squat by link standards.
Click to expand...
It is. And it is.
 
  • Like
Reactions: WSS
WSS said:
It is not really squat by link standards.
Click to expand...
Oh, that is exactly what it is. That is the very direct result of packaging over geometry. Wanna bolt on the mounts? Yes, okay, then you don't mind if we fuck the geometry so we can get the uppers hooked up to the belly skid, right? Nope, we don't mind, go ahead.
 
  • Like
Reactions: Chris
paulrobbyn said:
That’s what I’m thinking. I’m moving to 37’s from 35’s. Same width at 12.5. 4.5 BS wheels. Do the coilovers stick out pretty far after frenching them in?
Click to expand...
Everything else you have is making the job harder. Why not add in some 37s while you're at it?
 
  • Like
Reactions: Chris
mrblaine said:
Oh, that is exactly what it is. That is the very direct result of packaging over geometry. Wanna bolt on the mounts? Yes, okay, then you don't mind if we fuck the geometry so we can get the uppers hooked up to the belly skid, right? Nope, we don't mind, go ahead.
Click to expand...
So, straight out, if I want to run with the big dogs, Savvy mid arm? I have almost pulled the trigger a few times.
 
  • Like
Reactions: Apparition
Top Bottom
Back