Rubicon 4.5 Superflex shock length questions

Hi all -

I'm replacing my front shocks and am not quite sure I've selected the correct replacements.

I've got an old Rubicon Express 4.5 inch (6130) Superduty lift with 32" tires on my '98.

Old shocks were:
Rancho 9000x
The fronts are either the 99255's, or the 99256's

99255
15.875"/25.875"
99256
15.125"/24.000"

New shocks are:
Bilstein 5100 (24-185943)
17"/28.5"

I have pulled off one shock and am attempting to install the new one.

In that the new Bilsteins are longer when compressed than the Ranchos that were on there, are the new ones going to fit??? And in that the new shocks are longer when extended, is that going to be an issue?

The only way I can install the new Bilsteins is if I jack up the front end until I can fit the new shock in place. Is this the correct thing to do??

Thanks for the info.

J

sartor said:

In that the new Bilsteins are longer when compressed than the Ranchos that were on there, are the new ones going to fit??? And in that the new shocks are longer when extended, is that going to be an issue?

The only way I can install the new Bilsteins is if I jack up the front end until I can fit the new shock in place. Is this the correct thing to do??

Click to expand...

Without cycling the front suspension, with the coil springs removed, it's tough to know what length shock you need.

Jack it up, put the shocks on and see how much up travel you have, bump stop it enough to prevent bottoming.
I like to have a good half inch of shock up travel that never gets used....until you run over a washout, at speed, you didn't see soon enough.
Metal bends, make sure the shocks are not what limits the up travel.

Below is a list of commonly used shocks and their compressed/extended lengths. You can average the numbers to guesstimate what your lift might require, or better yet, cycle/flex and measure your specific suspension components.

With any lift and shock combination, you should be sure the bump stops are the correct length to prevent the shocks from bottoming out, or the tires from contacting the sheet metal.



.


Shock Lengths



(Brand/Model #) (Extended) (Collapsed) (Travel) (Position)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Napa 37083 (Stock) 21.2 13 8.2 Front
Monroe 32252 (* Stock) 21.25 13 8.1 Front
Monroe 37193 (* 1-3 “ Lift) 24.25 13.37 10.8 Front
Monroe 911524 (* UpCountry) 21.00 13.4 7.6 Front
Doetsch DT3350 ( 3-5” Lift) 26.5 15.5 11.0 Front
ES1000 ES124515 (* 3" Lift) 24.50 14.38 10.0 Front
ES1000 ES121515 (* 0-2" Lift) 21.52 12.72 8.8 Front
ES3000 ES324515 (* 3" Lift) 24.70 14.52 10.2 Front
ES3000 ES321515 (* 0-2" Lift) 20.24 12.45 7.8 Front
ES9000 ES921515 (* 0-2" Lift) 21.75 13.06 8.6 Front
ES9000 ES924515 (* 3" Lift) 24.70 14.52 10.2 Front
Skyjacker SJA-H7016 (* 1-3" Lift) 22.75 13.54 9.2 Front
Skyjacker SJA-H7025 (* 3-5" Lift) 24.75 14.54 10.2 Front
Skyjacker SJA-N8016 (* 1-3" Lift) 22.75 13.54 9.2 Front
Skyjacker SJA-N8025 (* 3-5" Lift) 24.75 14.54 10.2 Front
Skyjacker SJA-M9016 (* 1-3" Lift) 22.75 13.54 9.2 Front
Rancho RS5239 (* 3" Lift) 23.75 14.37 9.38 Front
Rancho RS5128 (* Stock) 20.87 13.00 7.8 Front
Rancho RS99239 (* 3" Lift) 23.75 14.37 9.38 Front
Rancho RS99128 (* Stock) 20.87 13.00 7.8 Front
Rancho RSX17317 (* 3" Lift) 23.75 14.50 9.25 Front
Rancho RSX13036 (* Stock) 20.50 12.87 7.6 Front
Bilstein F4-B46-1798 (Stock+Upcountry) 21.50 13.25 8.25 Front
Bilstein F4-BE5-6241-H8 (4” Lift)……………………………………….………….Front


(Brand/Model #) (Extended) (Collapsed) (Travel) (Position)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
NAPA 37027 (Stock) 20.0 12.8 7.2 Rear
Monroe 32269 (* Stock) 21.50 13.37 8.1 Rear
Monroe 37194 (* Upcountry) 21.12 13.87 7.2 Rear
Monroe 911525 (* Upcountry) 21.50 13.87 7.2 Rear
Monroe 37029 (1-3” Lift ) 23.00 14.375 8.6 Rear
Superlift SLF-85112 (* 2-4" Lift) 24.00 14.50 10 Rear
Superlift SLF-84140 (* 3-5" Lift) 26.07 15.57 10.5 Rear
Superlift SLF-85080 (* 0-2" Lift) 21.57 13.32 8.25 Rear
ES1000 ES124509 (* 3" Lift) 24.86 14.84 10 Rear
ES1000 ES121515 (* 0-2" Lift) 21.52 12.97 8.5 Rear
ES3000 ES324509 (* 3" Lift) 24.84 14.82 10 Rear
ES3000 ES322509 (* 0-2" Lift) 22.58 13.71 8.8 Rear
ES9000 ES922509 (* 0-2" Lift) 22.58 13.72 8.8 Rear
ES9000 ES924509 (* 3" Lift) 24.84 14.82 10 Rear
Skyjacker SJA-N8058 (* 3-5" Lift) 24.84 14.82 10 Rear
Skyjacker SKA-H7058 (* 3-5" Lift) 24.84 14.82 10 Rear
Doetsch DT-3000 (* 2" Lift) 22.50 13.50 9 Rear
Doetsch DT-3000 (* 4" Lift) 24.50 14.50 10 Rear
Doetsch DT-8000 (* 4" Lift) 24.50 14.50 10 Rear
Rancho RS5194 (* 2-3" Lift) 23.25 14.37 8.8 Rear
Rancho RS5259 (* Stock) 21.50 13.50 8 Rear
Rancho RSX13037 (* 0-2" Lift) 21.12 13.50 7.62 Rear
Bilstien F4-B46-1799 (Stock+UpCountry) 21.50 13.25 8.25 Rear
Bilstein F4-BE5-6686-H6 (4” Lift) …………………………………………….Rear



Note: * These lift heights were included where the shock lengths were found. These were the suggested shocks for that amount of lift. I have no way to ensure these numbers are accurate.

Front Shocks = Bottom Eyelet With Top Stud Mount
Rear Shocks = Bottom/Top Eyelet Mount

ok - good. Thanks for the information.

I've put the suspension into full crunch on one side and full droop on the other (as far as I can tell I've maxed it out). The way that I've currently got it set up, on the crunch side I've got 1" until the bump stop hits. I'm measuring 18" from the bottom of where the shock seats, to the sheet metal through which the shock pin goes. On the droop side I'm measuring 25".

With the Bilstein 5100's model 24-185943 measurements coming in at 17" compressed, so I think I've picked the wrong shock.

With the Bilstein 5100 model 24-188197, the specs are 14.88/23.84".

Looks like that's the shock I should go with, unless I wanted to change my bumpstops.

Sound right?