Shock length

[Witchdoctor]

Could any one tell me the compressed & open length of the front Mu shocks as well as the rear. I have a hair brain idea all you brainiacs would be able to help i hope.

Dave

[Bruce]

Now how long ago did I take them old ones to the tip and I played with them in and out, no there stuffed, should have measured them for u mate ;D
Cheers Bruce

[Paaji]

Not sure of the original spec dampers.
Rancho std part #'s give these lengths:
Front: Compressed 26.3525cm Extended 36.83cm
Rear: Compressed 35.2425cm Extended 54.61cm

Can check my old TJM ones on the weekend if you want.

Hope this helps

J

[pig75]

Just measured the stock shocks on my 90 MU

Front 250mm compressed & 375mm extended

Rear 335mm compressed & 560mm extended

[geeves]

That makes the std rears have 30mm more travel than the rancho. (the rancho fronts also have less travel but due to suspension design is not important) Doesnt say much for the rancho

[pig75]

My 91 MU has rancho 5008 rear and 5019 front they don’t make the 5019 any more. so use the 5029
the book lengths are
5008 34.92mm compressed 57.15mm extended
5029 24.44 compressed 36.19 extended

[JustinW]

My ARB front shocks are 245mm compressed and 385mm extended. These are matched to a 50mm suspension lift

[InVinceble]

Sorry to crash the party like, but what about us Bighorn guys
I've just measured the rear of my '94 at 325mm compressed and 505mm extended.
Now, what I really want to know is, if I go for a 50mm suspension lift what compressed and extended lengths should I be aiming for?
It's my belief that the compressed length should remain the same and the extended length increases by 50mm to accommodate the extra travel.
Expert advice as ever is greatly apprciated. ;D

[geeves]

For max extended length disconect one shock at the bottom only and jack up the back of the car on the chassis so the wheel gets full drop. Measure the amount of travel left in the shock and deduct this from the 505mm then add the 50mm + the amount your std suspension has sagged. This is your extended measurement. You will possibly find your std shocks are okay at 50mm lift.
Now the hard bit If you make your shocks longer you might not be able to match the compressed length. Then you have the choise of fitting blocks to your bump stops or relocating your upper shock mounts which requires certification but allows all sorts of extras articulation wise. Mulover has just done this on his Mu with the upper mounts moved towards the center of the body.
A generalisation with shocks is that most will take supporting the axle at full drop without damage but compress them to far and something will break not nessecsarily the shock. You might tear the mount off the chassis if the shock doesnt break first

[InVinceble]

Geeves, you are going to have to explain a little more clearly for me
"Measure the amount of travel left in the shock" - is this the amount of travel from it's "normal, at rest, before I disconnected the bottom, length" to the fully extended position?
"the amount your std suspension has sagged" - how do I know what this measurement is?
Additionally, as I'm contemplating having a swaybar disconnect system, I guess I should take this into account when jacking the rear up and measuring as I should get another 2" or so of lift.
I presume the front uses the same method of measurement - just the result will be more limited by the A-arm/torsion bar set-up.

[geeves]

Std hight measured at the gaurd under the xfer case is 210mm auto or 215mm if manual Assuming std hight tyres. You will have to do your own sums on this. The top of the front and rear gaurds is the same hight off the ground
When you disconect the bottom of the rear shock it will self extend to its max length. When you jack up the rear of the car on its chassis not the normal jacking point the wheel will drop to max . You will probably find that the shock is still 50mm too long to just pop straight back onto the mount.
One word of warning I just thought about. On leaf springs the sring controls the amount of travel On coils this is not the case. I dont know the later bighor suspension but the limiting factor is either a bump stop or the shock itself. If its the shock then the spring will be loose when fully lifted as described above. If it pops out you might need spring compressors to put it back.
If you can compress the spring to the bump stop you will find some travel left in the shock( Easier to work this out on paper Need lots of bags of cement to do it in practise ) Then just get the longest travel shock you can with this compressed length minus most of this extra travel.
For 50mm you will probably find std shocks are ok.
On the front with a 50mm lift you will need to do a ball joint flip All this is is remove the top ball joint then refit it but instead of the taper going through the A arm it sits completly underneath it.
This effectivly lengthens the A arm so camber can be adjusted. If you go more than 50mm you can fit spacers.

[JustinW]

Well I finally measured the back shock lengths in the Wizard (same suspension as a coil sprung Bighorn). Closed is 330mm and open is 520mm. These are for a 50mm lifted vehicle.
Now the head scratching begins. I'm going to try the EFS heavy duty shocks in the front, available in the new year. The EFS rear shocks need to have the EFS coils as well as the closed length is too long for the existing OME coils so I'm thinking of putting Koni shocks in the back. Any thoughts.

[InVinceble]

Just fitted Rancho 9000's front and rear to my "Bighorn". ;D
Went for RS99136 in the front and RS99180 for the rear (both rec. for Toyota) as the std. Isuzu items do come up a bit short for a 50mm lift.
99136 measure closed 282, open 448.
99180 measure closed 344, open 553.
Had to modify the bushes slightly (trim widths) to fit in the mounts. A new sleeve is required for the rear top bush too.
Only road miles so far, but feel much sharper, definately cut down on some body roll. Can't wait to get off into the forest.
Have fitted Maxitrac coils and uprated torsion bars. Very "orange"