TJ Shock & Spring Specification Resource Thread
- Thread starter Chris
- Start date
You are correct, I skimmed right past them
Lots of good info there
OP
Can you make this a Sticky @Chris ? I can see me coming here a lot.
Skatingdaddy
New Member
OK so I have a '06 with a lift the shocks are Rubicon RXJ701B front and RXJ704B for the rear. I would like to replace them what would be some recommendations? Also do i need to replace the springs as well? Just some info I am replacing the tie rods, sway bars and ball joints this weekend. I am ok mechanically i just don't know what to replace these shocks.
Thanks and look forward to your reply
Thanks and look forward to your reply
OP
@Chris
Add JKS 3" springs to the list. The specs from Andy at JKS are as follows:
Front is 20" long - rate is 150/220
Rear is 15" long rate is 190/240
I will probably be ordering these soon. Will update to measured lengths when I get them. I might even stack some weight on them to get a combined rate too.
Add JKS 3" springs to the list. The specs from Andy at JKS are as follows:
Front is 20" long - rate is 150/220
Rear is 15" long rate is 190/240
I will probably be ordering these soon. Will update to measured lengths when I get them. I might even stack some weight on them to get a combined rate too.
They are giving 4" of lift, according to the thread. That, in and of itself, isn't a problem, but their free lengths are not ideal for a 4" spring...so, I don't feel they would match up well to shocks that I would run for a 4" lift.
To be fair...I'm basing this on a bunch of numbers I have swirling around in my head. I haven't had much luck selling them and I assume it will cost almost as much to return them as I paid for them to begin with...So I probably should just install them and see for myself. I should pour myself a nice glass of bourbon, lock my door and spend some time in excel and thinking...
Wrap the ends in tape to prevent scratching during the test fit. Don't tell Morris 4x4, but I did that years ago on a couple sets.
OP
TheShakes90
Member
@jjvw just to make sure I'm using your work correctly to calculate some stuff. I don't know what the PO put on for my 2.5" lift kit so I can't accurately calculate my ride height, so I'm gonna have to rely on the theoretical X" lift numbers from the manufacturers
Assuming springs are the limiting factor and using the Moog Rear Springs for my control numbers. Free length of 11.25" and a standard ride height about 8" means the springs should allow 3.25" down and about 4" of up travel. Does this look right to calculate most of the other springs?
Assuming springs are the limiting factor and using the Moog Rear Springs for my control numbers. Free length of 11.25" and a standard ride height about 8" means the springs should allow 3.25" down and about 4" of up travel. Does this look right to calculate most of the other springs?
Your ride height is the measurement from the top of the spring to the bottom of the spring. Subtract the stock ride height from your measurement and that is the lift height.
What you don't know, unless you know what springs are currently installed is how to calculate the sprung weights.
FWIW, the manufacturer's advertised lift height is only a guess. The manufacturer does not know anything about how heavy your Jeep may or may not be compared to the Jeep they tested their springs on to arrive at their advertised lift height.
The up and down travels are determined by the shock. Unless you use a dumb spring like Metalcloak that can require added bump stop extension compared to a normal spring of a similar ride height. The travel bias of the shock is determined by the ride height created by the spring. The goal is a 50/50 shock travel bias.
Last edited:
Those dumb MetalCloak 4.5” fronts go solid at 8” not 9.5”, also free length is 23.75“ not 24”
The 4.5" and 6" rear free lengths are off by a small fraction. And they never used to say approximate. The solid heights are correct and that is the primary reason I think MC springs are dumb.
So the solid height of 9.25” for the front 4.5” springs is your approximation? That’s dumb, where did you get that dim. from? Technical information should be objective or it’s trash.
Let's delete this whole thread since nothing can be trusted. Or @Chris can correct the mistake and we can all move on from this travesty.