66-77 Bronco suspension (Longer Travel)
Chris Cothrun
I have a few ideas on suspension mods on my 72 Bronco, please
give me your opinion. I was at the 30th anniversary in Apple Valley,
and I saw the blue Proto Fab Bronco (Todd Zuercher) run Jackhammer. I
was somewhat impressed. I also saw the Cold Duck Broncos in action,
and while they were not as impressive as the Proto Fab Brnc., they
were also impressive. I bought the Cold Duck manual to see if they had
good ideas, and they did. They suggested the angle of the radius arm
doughnut bushing was too extreme. They did not want to use a radius
arm drop bracket (too much lost clearance, I agree) so they cut wedges
out of the stock bracket and changed the angle to keep the bushings
from binding up suspension travel. In doing this they had to cut the
radius arms and lengthen them about 1\2 an inch. I don't like that
idea too much so I say why not make a whole new bracket with the
proper angle and about 1\2 inch forward. I know it would take a lot of
work to do it properly, but so would lengthening the radius arms. Wild
Horses Four Wheel Drive solves the problem by using soft rubber
bushings, but that almost seems like a weak fix. That might make the
bronco handle sloppy. If you want to lengthen the radius arms you
might as well lengthen them a foot or two like Proto Fab. What gains
do you think lengthening the radius arms would give? Is it worth it?
I currently am running James Duff 3 and 1\2 inch lift on my
bronco. The rear sat much too high and was much too stiff and the
front sat lower on the drivers side than the passengers side. I tested
it on the suspension test ramp at the 30th and was unimpressed. I did
get a picture of my rig in 4 by 4 Mechanics Magazine (on the twist
ramp) but I felt its suspension sucked compared to others. I asked
James Duff himself to look at my suspension on the ramp and tell me
why it didn't work. He said my shocks were bottoming out, so I removed
the shocks and went back to the ramp, no improvement. James Duff
didn't have much to say after that. When I got home I removed the baby
add a leaf and replaced the James Duff huge thick overload springs
with stock overloads in my Duffy replacement springs and put a shim in
to help out my pinion angle.
Result, it rode better traveled much better and sat lower, although it
still sat higher in back than in front. The only thing holding up
travel is the Duffy shocks bottom out and top out. Solution, make
custom mounts and run long travel shocks. I'll do that front and rear.
I am going to do my radius arm bracket trick, run Wild Horses
rockcrawler springs and center my front driveline. I need to run power
steering. The kit says you need at least 3 inches of lift which I
have. Do you think steering geometry is "proper and good" with the
power steering kit?
Im going to make a 1 inch body lift out of solid aluminum
stock. I already have polyurethane body mounts. It will be easy. Im
going to run 35s when my 33s wear out. Right now Im building a 23
degree suspension ramp of my own, so I can test my and my friends
suspension and find out proper shock locations.
I am currently looking for the cheapest way to run a C4 auto.
Where is the cheapest place to find an adapter? What are the best C4s
to run?
Future plans are a big bearing rear end with a Detroit Locker
and 31 spline axles and an EZ locker in front. I have 4.11s now, with
an auto and 35s and a healthy 351w, what gears would you run for
rockcrawling and driving on the street?
Thanks for taking your time and reading my questions. I'd
appreciate your opinion and any ideas of your own. If you know the
cheapest way to do things, tell me please. Im a full time student and
have a low income, so any ideas would be welcome.
coby hughey
Boy, I felt like I was reading about my own adventures with a bronco
while reading this. One thing I'd heartily recommend is to join the Early
Bronco Mailing list. Just email jga...@pepperdine.edu and ask to subscribe.
The messages can be fast and furious, to the tune of over 100 emails a day,
though 30 is more like the average.
> I have a few ideas on suspension mods on my 72 Bronco, please give me
> your opinion. I was at the 30th anniversary in Apple Valley, and I saw
> the blue Proto Fab Bronco (Todd Zuercher) run Jackhammer. I was somewhat
> impressed.
Todd has an outstanding rig, and he is very intelligent and
knowledgeable. He's a regular on the mailing list.
I also saw the Cold Duck Broncos in action, and while they
> were not as impressive as the Proto Fab Brnc., they were also
> impressive. I bought the Cold Duck manual to see if they had good ideas,
> and they did. They suggested the angle of the radius arm doughnut
> bushing was too extreme. They did not want to use a radius arm drop
> bracket (too much lost clearance, I agree) so they cut wedges out of the
> stock bracket and changed the angle to keep the bushings from binding up
> suspension travel. In doing this they had to cut the radius arms and
> lengthen them about 1\2 an inch. I don't like that idea too much so I
> say why not make a whole new bracket with the proper angle and about 1\2
> inch forward. I know it would take a lot of work to do it properly, but
> so would lengthening the radius arms.
If you really wanted to solve the problem, just weld heim joints on
the end of the radius arms and mount them.
I have the Wild Horses rubber bushings. (stock bushings are rubber
too). They do not contribute to sloppy steering at all. As a matter
of fact, I love my steering; it's good to 120 mph as tested by
me...:)
Wild Horses Four Wheel Drive
> solves the problem by using soft rubber bushings, but that almost seems
> like a weak fix. That might make the bronco handle sloppy. If you want
> to lengthen the radius arms you might as well lengthen them a foot or
> two like Proto Fab. What gains do you think lengthening the radius arms
> would give? Is it worth it?
Again, I'm not sure it's worth it. I've been rather happy with my
suspension since I installed it last year; but it still needs more
testing to see what improvements can be made short of going to a
custom 4link.
> I currently am running James Duff 3 and 1\2 inch lift on my bronco. The
> rear sat much too high and was much too stiff and the front sat lower on
> the drivers side than the passengers side.
Had it. Hated it. Gave it away.
I tested it on the suspension
> test ramp at the 30th and was unimpressed. I did get a picture of my
> rig in 4 by 4 Mechanics Magazine (on the twist ramp) but I felt its
> suspension sucked compared to others. I asked James Duff himself to look
> at my suspension on the ramp and tell me why it didn't work. He said my
> shocks were bottoming out, so I removed the shocks and went back to the
> ramp, no improvement. James Duff didn't have much to say after that.
yea, Duff's a funny guy.
> When I got home I removed the baby add a leaf and replaced the James
> Duff huge thick overload springs with stock overloads in my Duffy
> replacement springs and put a shim in to help out my pinion angle.
> Result, it rode better traveled much better and sat lower, although it
> still sat higher in back than in front.
One thing to remember is that the bronco came from the factory
tail-high. I'm tail high too, although by purpose. (I ran 11 leaf
nat'l springs instead of 10 leaf). I rather like the additional
view over the hood.
The only thing holding up travel
> is the Duffy shocks bottom out and top out. Solution, make custom mounts
> and run long travel shocks. I'll do that front and rear. I am going to
> do my radius arm bracket trick, run Wild Horses rockcrawler springs and
> center my front driveline. I need to run power steering. The kit says
> you need at least 3 inches of lift which I have. Do you think steering
> geometry is "proper and good" with the power steering kit?
Hint: give your bronco the maximum body lift you think you will ever
need before welding in the shock hoops. Then, you can buy hoops
that will go all the way to the top of the inner fender and you can
use the longest shocks you can find. Another hint is to use only one
Rancho 9000 in the front to begin with. I bought two for each side
in the front, but ended up using only one. At 3, it's a perfect
street ride. At 4, I can do spirited canyon handling(I live in
Colorado). At 1 or 2, I can rockcrawl and flex like a champ. With
twin shocks, the damping is too much; there's not any leeway to go
soft.
One more experience tip is to run a 3.5 lift, Wild Horses drop trac
bar bracket, and the 2wd F150 ps conversion. This leaves your
draglink and tracbar in almost perfectly stock locations, with nearly
parallel relationship between the drag link and tracbar, which
eliminates bump steer. Oh, and make sure you *weld* the tracbar drop
bracket. I didn't, and broke it jumping at the sand dunes. Jim was
nice enough to send another one, but I really should have welded it
the first time.
Try the stock radius arms with the soft rubber bushings first; if you
find it's still limiting you, then do the work to modify it.
> Im going to make a 1 inch body lift out of solid aluminum stock. I
> already have polyurethane body mounts. It will be pretty easy. I'm going
> to be runnning 35s when my 33s wear out.
I have a 1 inch body lift using hockey pucks. I wouldn't go over 1
inch with pucks, but I don't see any problem with 3 inches of body
lift. I just wouldn't do it myself. I'm buying some 36x12.5's next
week, and I think I will have to cut larger fender cutouts to run
them in the rear. I had 33" swamper radials, but they bit.
Right now Im building a 23
> degree suspension ramp of my own, so I can test my and my friends
> suspension and find out proper shock locations.
Why a 23 degree ramp? Why not the standard 20 degree?
> I am currently looking for the cheapest way to run a C4 auto. Where is
> the cheapest place to find an adapter? What are the best C4s to run?
Gosh, I couldn't tell you where to find an adapter besides the bronco
houses and Advance Adapters. Mine had one stock.
Run a Bronco C4 if you can; if you can't, run one that's been built
right.(Bronco C4's were built differently; tougher)
I burned out two C4's last winter, and then I had it built by
a local guru and it's been holding up great, even to my new 351w with
twisted wedge heads. Make sure you run the biggest damn tranny
cooler you can.
> Future plans are a big bearing rear end with a Detroit Locker and 31
> spline axles and an EZ locker in front. I have 4.11s now, with an auto
> and 35s and a healthy 351w, what gears would you run for rockcrawling
> and driving on the street?
I have the small bearing rear with a Detroit in a nodular housing and
28 spline axles and I haven't broken the rear axles yet. (god knows
I've tried....I love wheelstands) My motor's rated around 400 hp,
400 ftlbs torque, and the rear axles are doing fine so far. I've
broken three ujoints in the stock 44 front axles(two left, one right)
and tomorrow I'm picking up my new, 1 3/16" ujoint axles for the
drivers side. (tired of breaking). I also have 4.11's, 33's, and I
*might* go to 4.56's. We'll see. I can do high speeds on the
highway now, although it's a little high in the rpm's. I'll be
running 31's on the street, and 36's on the trail, so I'll probably
keep the 4.11's. I'm just waiting for the Cold Duck second xsfer
case to appear; I want to see it in action before plunking down
bucks.
> Thanks for taking your time and reading my questions. I'd appreciate
> your opinion and any ideas of your own. If you know the cheapest way to
> do things, tell me please. Im a full time student and have a low income,
> so any ideas would be welcome.
>
I hear ya, I'm fulltime too. If it wasn't for my windfall....I'd be driving a
jeep. (shudder)
These toys get expensive.
--
Coby Hughey
"By US Code Title 47, Sec.227(a)(2)(B), a computer/modem/printer meets the
definition of a telephone fax machine. By Sec.227(b)(1)(C), it is unlawful to
send any unsolicited advertisement to such equipment. By
Sec.227(b)(3)(C), a violation of the aforementioned Section is punishable by
action to
recover actual monetary loss, or $500, whichever is greater, for each
violation."
Mindwarped
Ok, I read through the entire novel (just kidding, i love bronco talk)
And now i think i am ready to attempt to comment on it.
One thing i read was cutting and lengthening the radius arms.
Personally I dont care how good of a weld the guy uses, the strength just
will not be up to par with original. For only a measly half inch, it just
seems like a lot of work to do very little that just isnt going to be
strong enough. On the other hand using the lengthened arms by Proto-Fab
(how much are they anyway??? ) You have a solid arm that wont break. The
added length means that at the rear point, there will be less of a change
in the angle from top to bottom of the axle movement. This means a lesser
amount of pressure and binding at the bushing. add this to the extra
leverage and other geometry and it adds up to more travel.
About the rubber bushings, I think that they were talking about using
the stock rubber ones that are original to the truck.The point being that
the stiffer compound of the poly bushings that people use as replacements
is too stiff and will limit or slow down wheel travel, and that the stock
will allow more movement. About the sloppiness, use new rubber for the
radius arms, and poly for the rest. Most of the slow comes from the C
bushings and the tracking bar anyway.
Your lift questions now....
what kind of shock mounts do you currently have? The stock mounts in
the front are a severe limitation to wheel travel, upgrading to a
lengthened hoop mount will give you something like 3 inches of extra
travel. Also I know that there were three different GVWR sets of springs
available for broncos. Do you know which you have? that may make a
difference in the ride quality.
For a C-4, a swap that i am currently half done with.... (no engine
or tranny in mine at the moment) I lucked out and found an original
bronco C-4 and the adapter housing, but needed to buy some extra parts
since it wasnt all there.
The original C-4 from a bronco is stronger than most car versions, and
Toms Bronco Parts sells an original C-4 and adapter, I think it may be
rebuilt already, ready to drop in just needs a shifter, for $495-$595
Actually, probably need a torque converter and flexplate too. Best bet
for a shifter is any aftermarket one that uses a cable, most even have the
Neutral safety built in.
I have 4.11's myself, since it was originally a 6cyl, and i'd say keep
em, or maybe if the 35's make it bog too much, go with 4.56. Hell, Sounds
like you are better off then me, I have a rusty 67 with a dana 30, no
lift, and running 32's
Ever notice there isnt much brono info out there? That bronco history
book isnt that great all it is, is a collection of magazine articles from
the 60's, nothing really that interesting either. Hell, if enough people
wanted to get in on it, i would say put one out, we all put in the
buildups of our own trucks, real world stuff, ya know?
Anyway, feel free to ask away anything you may want to ask.
THis is the NEW AND IMPROVED signature
for the OnE AnD OnLy MindWARPED
67 Bronco, and dont even ask, its NOT for sale
Chris Cothrun
co...@holly.colostate.edu (coby hughey) wrote:
> Right now Im building a 23
>> degree suspension ramp of my own, so I can test my and my friends
>> suspension and find out proper shock locations.
>Why a 23 degree ramp? Why not the standard 20 degree?
When I decided to build a suspension ramp, I had no idea what angle to
use. I first called Wild Horses. The guy there wasn't real sure on
theirs, but he thought it might be a 20 degree. I called 4 wheel drive
shops, magazines, just about anyone I could talk to on the subject,
but nobody knew much. Finally I talked to a guy in Arizona who worked
in a fabrication shop. He said thier shop built the ramp for Four
Wheeler magazine. He pulled the paperwork on the specks for the ramp
and said 23 degrees it was. He said some people used 20, 26, 28, 17,
etc..., but 23 was the standard. He seemed to know what he was
talking about. Pictures of other ramps I've seen almost look steeper,
but pictures are deceiving. My ramp is 10 feet long, 20 inches wide
and really close to 4 feet tall at the higest point. Where did you
get 20 degrees for a standard? You might be right, but I hope not. I
spent a lot of money on metal.
Thanks for the info. I also have Trick Flow heads on my
Bronco. 340 Horse is closer to my estimation for power, but much more
could be made. What did you have to do to your C4 to make it handle
the power?
Would you know where to find information on desert race
suspension of all kinds, like how to build it, how it works, etc. I'm
sure suspension fabricators wernt born with the knoledge. I bet a lot
of desert race tech. could be used in rockcrawlers, sand runners, and
four wheel drives in general. I have some fabrication skills and
would like to put them to use on cool stuff like four wheel drives.
You are putting 36/12.5s on your bronco? Are they the Super
Swampers? how would you compare Swampers with BFG mudders, like say
sidewall strength?
Sam Cothrun on his bro's email
coby hughey
In article <32cddfb3...@nntp.ix.netcom.com>, cri...@poboxes.com spouts...
>
>co...@holly.colostate.edu (coby hughey) wrote:
>
>
>> Right now Im building a 23
>>> degree suspension ramp of my own, so I can test my and my friends
>>> suspension and find out proper shock locations.
>
>>Why a 23 degree ramp? Why not the standard 20 degree?
>
>use. I first called Wild Horses. The guy there wasn't real sure on
>theirs, but he thought it might be a 20 degree. I called 4 wheel drive
>shops, magazines, just about anyone I could talk to on the subject,
>but nobody knew much. Finally I talked to a guy in Arizona who worked
>in a fabrication shop. He said thier shop built the ramp for Four
>Wheeler magazine. He pulled the paperwork on the specks for the ramp
>and said 23 degrees it was.
I'm not too surprised. Fourwheeler claims it is a 20 degree ramp, but I
believe the differing responses you got. I understood it to be 20 degrees
from responses from different clubs and from Fourwheeler. I think the RTI
score should include the degree chosen as part of the score, as differing
degreed ramps would produce differing RTI numbers. What was the slope of the
ramp at the Bronco 30th?
He said some people used 20, 26, 28, 17,
>etc..., but 23 was the standard. He seemed to know what he was
>talking about. Pictures of other ramps I've seen almost look steeper,
>but pictures are deceiving. My ramp is 10 feet long, 20 inches wide
>and really close to 4 feet tall at the higest point. Where did you
>get 20 degrees for a standard? You might be right, but I hope not. I
>spent a lot of money on metal.
Let's see...10 feet long(of ramp...bottom peice would be shorter)
would make it (sine23=height/10) 3.91 feet. Sounds perfect. Does anyone else
have input on the 'standard' of ramp travel? I'd love to resolve this...
BTW...you can convert differing RTI scores if you know their angle. See a
previous thread on ramp travel index.
> Thanks for the info. I also have Trick Flow heads on my
>Bronco. 340 Horse is closer to my estimation for power, but much more
>could be made. What did you have to do to your C4 to make it handle
>the power?
I had Butch Brooks in Loveland build it last winter for my 140hp 302. I had
burned up two trannies that winter, and I was tired of it, and he came
recommended. The C4 will take a 351 without too much problem at all if it's
built right, and ***COOLED*** adequately. Put a shift kit in; it reduces
slippage which reduces heat buildup.
My 351w was built with 10.5:1 cr, hypereutectic pistons(tight piston/wall
clearance), Crane 272 cam, with .488 intake, .512 exhaust, the bowls were
touched up by Airflow Design and Components, it was balanced to 1/10th a gram
at 5 inches, blueprinted in a '69 351w block. The hp figure was not taken from
actual dyno(too damn expensive here....grrr) but from the Desktop Dyno, which
usually is within 5 percent. We're running about 42 total degrees of advance,
btw.
> Would you know where to find information on desert race
>suspension of all kinds, like how to build it, how it works, etc. I'm
>sure suspension fabricators wernt born with the knoledge. I bet a lot
>of desert race tech. could be used in rockcrawlers, sand runners, and
>four wheel drives in general. I have some fabrication skills and
>would like to put them to use on cool stuff like four wheel drives.
I'd love to spend more time studying desert race tech, but I haven't. Check
with some of the SODA racers; they do it on a budget and seem to have some good
tech under their belt. However, there are many folks that have done 4link coil
suspensions for their Bronco's, and some have gotten pretty wild.
> You are putting 36/12.5s on your bronco? Are they the Super
>Swampers? how would you compare Swampers with BFG mudders, like say
>sidewall strength?
>
I'm still up in the air between the TSL's, and the TSL/SX's. (gotta get them
next week; couldn't get them today) The lugs are a little deeper and wider on
the normal bias ply TSL's, but the SX's have the sidewall lugs and stronger
sidewalls. As far as sidewall strength goes, we do *lots* of rocks here and no
one I know has ripped a sidewall on a Super Swamper *or* a BFG MT. However,
the tread on a swamper is softer and stickier(better for rocks), has better
lugs(better for rocks, mud, and snow bigtime), but it doesn't have the onroad
manners of the BFG MT. This type of terrain is ruled by the Super Swamper, and
lately by the Bogger(although in snow, you can go forward but you best not try
to reverse). Also seen is the Buckshot Mudder.
>Sam Cothrun on his bro's email
>
>
>
>
>
--
ROKBRNC
I'm currently running 35's on my '68. I am getting about 21"'s of travel
in the rear and about 14"'s up front. The #1 limiting factor of travel on
early Bronco's is the shocks! I have fabricated my own suspension w/ the
help of of National Springs. I use their progressive rate 3 1/2" springs
up front w/ their 3 1/2" multi-pack springs in the rear (they look huge
but, they ride and work great!). They are pretty soft compared to all of
the other springs available (which are junk)! I cut-off my front and rear
shock mounts and welded up my own which are identical to the original's
but, they are 4"'s longer to allow room for longer shocks. Another trick
you can use is to go to a salvage yard and pick up a set of shock towers
from a late model F-250, they bolt on and they are 3"'s longer than bronco
towers. It's a lot cheaper and easier than what you had in mind. I have
a real hard time lifting tires and I cruise the Rubicon and Fordeyce
trails regularly. If you are still looking for more travel then you will
probably need to go w/ longer radius arms and extremely long shock towers
which will require you to bring them inside the bed area and engine bay
which might not gain you much more travel vs. the cost involved.
coby hughey
In article <19970108015...@ladder01.news.aol.com>, rok...@aol.com
spouts...
>
>I'm currently running 35's on my '68. I am getting about 21"'s of travel
>in the rear and about 14"'s up front. The #1 limiting factor of travel on
>early Bronco's is the shocks!
So what's the limiting factor now? I'm running shock hoops that hit the top
of the inner fender with a 1" body lift. (hoops from Wild Horses)
Shocks don't limit me.
How exactly do you measure travel? I'd like to compare mine to you. What is
the resting distance from the axle tube top to the bottom of the frame? What
is the maximum compressed distance? The maximum extended distance? I'll try
to take measurements tomorrow, using both the left and right side of the front.
I'll do rear later.
I have fabricated my own suspension w/ the
>help of of National Springs. I use their progressive rate 3 1/2" springs
>up front w/ their 3 1/2" multi-pack springs in the rear (they look huge
>but, they ride and work great!).
I agree about the national leafs; I'm running the 11 leaf pack in the rear, and
it flexes great.
They are pretty soft compared to all of
>the other springs available (which are junk)!
I would emphatically disagree with that. The rockcrawlers from Wild Horses
outperform any other spring I've seen yet for the early Bronco, and by a wide
margin. With my shocks turned to 1, I can bounce the front of the rig with one
hand over a foot up and down. Soft isn't even the word. Of course, the spring
works best(softest) with a winch and winch bumper; a friend has the same set
with even longer shocks(he's running a 3" body lift, and shock hoops to the top
of the inner fender) but without a front bumper's weight, it doesn't compress
as well as mine.
Where do you live? I'd love to see if yours are softer; if they are, that
would be a great resource for the other bronco owners.
I cut-off my front and rear
>shock mounts and welded up my own which are identical to the original's
>but, they are 4"'s longer to allow room for longer shocks. Another trick
>you can use is to go to a salvage yard and pick up a set of shock towers
>from a late model F-250, they bolt on and they are 3"'s longer than bronco
>towers. It's a lot cheaper and easier than what you had in mind. I have
>a real hard time lifting tires and I cruise the Rubicon and Fordeyce
>trails regularly. If you are still looking for more travel then you will
>probably need to go w/ longer radius arms and extremely long shock towers
>which will require you to bring them inside the bed area and engine bay
>which might not gain you much more travel vs. the cost involved.
Has anyone done the quarter elliptical springs for the Early Bronco?