Ballpark shock length estimate

[CityHick]

Over the weekend I installed some new rear shock mounts in my EB. I went with the WH Shock Jock because I didn't feel like fabbing my own. They are pretty nice - they easily added two inches of shock length over stock, and the install was pretty easy too.

I have known for a while that the rear shocks sold to me when I bought my 5.5" suspension lift were too short even for my stock shock mounts. Now with the new mounts, they are fully extended (28") just to reach between the upper and lower mounts. So with 28" as my nominal shock length, I'm thinking that 33" fully extended and 19" fully compressed (13" travel) should be adequate. I will have to make sure my bump stops limit my up travel, but I'm curious what you all think about having a shock that will give only 9" droop.

Here's the way I figure it:

33" - 28" = 5" ==> This is my up travel before bump stops are installed
33" - 19" = 14" ==> This is my total shock travel
14" -5" = 9" ==> This is my droop travel.

Is 9" of droop adequate for 5.5" WH leaf springs? Or are they capable of more than that? I know that you absolutely can't let a shock serve as a limiting strap... so I want to make sure that my shocks are capable of more travel than my leafs are. I called WH this morning and they didn't really have an answer so I figured I'd ask the masses here.

I plan to make use of a forklift pretty soon to take some actual measurements, but does it sound like I'm in the right ballpark?

-Tony

[Filgas]

Re: Ballpark shock length estimate

I'd get it on the forklift and find out your compressed length. Get the shock that has the most travel available with a minimum length less than your compressed length. Then limit droop if necessary.

[SonicDonkey]

Re: Ballpark shock length estimate

I think you have your #'s mixed up.

If your static/nominal mounting length is 28" and your shock extended length is 33" you get 5" of droop not 9". Likewise if you have a 14" travel shock and 5" is droop you then get 9" compression.

I think with leafs you would be better suited to use a 40/60 balance of compression to droop but then again, depends where you need your bump stops.

If you want to make 33" shocks work, you would probabaly need to mov your axle mounts up 3" or so.

[CityHick]

Re: Ballpark shock length estimate

Sonic I think you're right... this is what I get for trying to brainstorm about this stuff between tasks at work!

I just sketched it out on paper and you're exactly right - to go from 28" to 33" the axle droops 5". That hardly seems like enough droop. I guess the forklift test will show me exactly where I'm at. I really need to know exactly how much the leaf spring will allow the axle to droop and I guess that's my real question to people here - how much will your 5.5" WH leaf spring droop? With the shocks angled back vs straight up and down its not a linear calculation - the front is easier to figure because the shock is vertical.

I can't imagine how I would go about moving the axle mounts up 3", however that would put me at 8" of droop and 6" bump which sounds more like it. Hmm...

Or go to a 36" shock, 21" compressed and it shakes out like this:

28" nominal, 8" droop to 36" full extension
28" nominal, 7" bump to 21" fully compressed

Before my head spins, I need to put the beast on a forklift!
Thanks for straightening me out Sonic!

[Bronco Brian]

Re: Ballpark shock length estimate

[QUOTE=CityHick;59728]I guess that's my real question to people here - how much will your 5.5" WH leaf spring droop? QUOTE]

With no axle on the springs they will droop 17.5" Top of spring to top of frame in the center. This is what mine are with the frame on jack stands

[TRAILBOUND]

Re: Ballpark shock length estimate

are you sure about that brian, cause a spring should only droop as far as the shackle. at static the shackle points pretty much straight up and fully down is only 90*. Stock and after market replacement shackles are what 5-6". And a 90* would be just leveling it out, so roughly 5-6" of droop. Cause the springs themselves, especially 5.5's aren't gonna give you much droop over the shackle drop. They are just to stiff of a spring.

[Bronco Brian]

Re: Ballpark shock length estimate

are you sure about that brian,

100% that is my spring just hanging from the frame no extra weight.
This so he can measure his sitting on the ground and find the difference