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James Duff 70/30 shocks

rustbucket

Bronco Guru
Joined
Mar 22, 2004
Messages
1,579
I installed a James Duff 3.5” suspension lift with front hoops on my ‘73 many years ago. At the time, i didn’t install the necessary brackets for the dual shocks at each corner, so have run single 70/30 on each corner since. So my question is, for those who have been in my shoes, what was the difference when you installed the second shock? Better control? Better ride? Is it worth it? Should I go with single Bilstein’s?


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Z Bronco

Bronco Guru
Joined
Mar 17, 2007
Messages
1,141
I went with the dual Duffs after checking out the Bilsteins. My Bronco is heavy with plate numbers and other rock armor. My Bronco handles and drives great, plus the cost of shocks was a lot less. It was recommended that I do dual Bilsteins on the front.
 
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rustbucket

Bronco Guru
Joined
Mar 22, 2004
Messages
1,579
I went with the dual Duffs after checking out the Bilsteins. My Bronco is heavy with plate numbers and other rock armor. My Bronco handles and drives great, plus the cost of shocks was a lot less. It was recommended that I do dual Bilsteins on the front.



Did you ever drive it with just single 70/30 shocks in each corner? Just wondering what effect I would get by adding the second shock per corner.


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75MIKE

Contributor
Sr. Member
Joined
Aug 22, 2001
Messages
977
Loc.
NE Washington
Ran mine with dual 70/30's in the front and singles in the back for many years. Tried the Bilsteins for a year and went back to single 70/30's all around. Will stay with the 70/30's. They just ride better.

The Bilsteins just felt stiffer. Also they seemed like when you'd drop a tire in a hole the opposite side shocks were trying to lift up.

My 2 cents.
 

DirtDonk

Contributor
Bronco Guru
Joined
Nov 3, 2003
Messages
49,452
Well that's interesting. Most that feel the Bilstein 5100's are not quite right for their Bronco feel they're too soft!

But either way rustbucket, going from one shock to two per wheel is not to make it ride better but more to benefit in other ways.
Of course that "better" is up to personal preference too. It will be firmer, but that might be good for some Broncos and some owners.
It should certainly corner tighter, handle big bumps better, and may end up being preferred by you. It might even ride smoother over your particular local terrain.
But one thing it won't do is ride "softer" on the road.

I've done both (but not with the Duff shocks specifically) and have both loved and hated it. It was all about the shocks and the balance of the vehicle and the conditions.
I have dual mounts on my '68 and am still going to install the mounts on my '71, but am also going to experiment with shocks. First going with dual Bilstein 5100's just to see how I like it.

Nothing wrong with trying. Other than the little bit of extra time it will take you to weld on the new mounts you have burning a hole in your garage!
Do you have the parts and shocks needed to run duals? Or are you contemplating it and still need to purchase it all?

Sounded like you already purchased the stuff, but never installed it. If it was me and I had the stuff already, I'd go ahead and install it.
Sometimes we just gotta play around. Ya know?;);D

Paul
 

Local Boy

Jr. Member
Joined
May 23, 2016
Messages
191
Loc.
Mililani, Hawaii
^^^ Paul is... as always.... spot on!

It really depends on the weight over the front axle (for front shocks)... as it relates to what Paul has described... above...

I will add that if you go dual's (front or rear - doesn't matter) its really important to have a different valving set-up (lighter), as a single (shock) set-up would have a stiffer valving configuration because they must handle all the forces by themselves...As for dual set-ups...there are now two shocks sharing the load...making them too stiff if they have the same valving as a single shock set-up...

If I remember correctly...for the general size and weight of our Broncos.... 255/70 is recommended for single shock set-ups....and 155/80 is recommended for dual shock set-ups...

This approach has worked flawlessly for me...

Aloha
 
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rustbucket

Bronco Guru
Joined
Mar 22, 2004
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1,579
I already have all the shocks and mounts. They came with the lift kit when I bought it. I just never installed the second shocks. I may go ahead and install them and see how they work. Most of the roads around here are so pot holed you would think they were carpet bombed!


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TDubya

Sr. Member
Joined
Aug 3, 2009
Messages
381
Loc.
Fortuna, CA
When I first installed my Duff 3 1/2" inch lift I only had single 70/30 shocks installed in the front for a week until I could weld the bottom shock mounts to the radius arm caps. I didn't like the way it handled on the highway with single shocks on the front. After adding dual 70/30 shocks, the handling on mine was much better. I don't feel that it rides to harsh for what it is; a 45 year old, short wheelbased 4x4!
 

Rustytruck

Bronco Guru
Joined
Feb 24, 2002
Messages
10,875
I run a single 70/30 up front and adjustable Rancho 9000 in the rear due to the leaf springs in the rear. Ran singles and duals and several brands just not any bilstines. Problem is no 2 Broncs are sprung or set up the same. Flat springs dont work the same as coil springs do and need different shock control.
 

Z Bronco

Bronco Guru
Joined
Mar 17, 2007
Messages
1,141
I have run dual shocks for years. From Rancho soft valve shocks designed for double shocking, the Doetch Tech MV 12s, and now the Duff shocks. I have a WH 3 1/2" suspension with the extreme hoops in front and the Shock Jock in back (modified by drilling an extra hole in the upper mount). I have full articulation with the Duff shocks, the ride and handling is great. Very happy with my setup.
 
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