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Modifications to 77 EB

Tuff68

Full Member
Joined
Dec 27, 2005
Messages
325
Loc.
Hermitage, TN
With the steering linkage being different on the 76 & 77 Bronco's can I add a small sup. lift ( 2.5" ) and over size wheels with out a lot of issues.
I have added a 3" like to my 72 and just wanted to make sure I would not run into something different of the 77 I have.
Also with the 77 having factory front disc brakes what is the best wheel offset to use and will 4" offset be too much.

Thanks again for the information
 

Socal Tom

Bronco Guru
Joined
Feb 12, 2004
Messages
2,442
Loc.
San Diego, CA
The rule of thumb is if you go over 3 inches you need a drop pitman arm and a drop trac bar bracket. This is regardless of year You still want to use the c-bushings to the radius arms, but you probably only need 4 or 5 degrees.

Can't help you with the wheel offset.
Tom
 

tasker

Contributor
all knowing of nothing
Joined
Jun 2, 2006
Messages
20,710
Loc.
NH
My 73 has the 76-77 steering linkage on it for some strange reason. When i put my 33's on 8" wheels the tierod caught on the wheel weights. It looked like the back side of the wheel went through a lathe. Just double check that stuff before you take it for a ride like i did!
 

cgbexec

Bronco Guru
Joined
Sep 19, 2006
Messages
2,071
Loc.
Naples, FL
As far as backspacing why don't you just measure it? I used a plumb-bob on a string and measured from the edge of fenderflare to the floor and made a mark (I wanted the widest point of the tires to be just inside the outer edge of the flares - that is what this mark is). I then dropped the plumb-bob from the face of the rotor hat (where the rim makes contact with the rotor) to the floor and made a mark (this would be the center of the rim with 0 offset). If your tires are 10" wide (not rims), then the outer edge of your tire will be 5" out from the mark you made for the rotor face with 0 offset. To push the tire out towards the outer mark (edge of the vehicle) add inches to until you have the tire where you want it. Depending on how wide your tires are and how far out you want them to stick is going to determine backspacing. Most set-ups are going to be 3.25" to 4". I wanted the edge of my 35X12.5" tires to be just inside the edge of the flares(aftermarket). I think I ended up at 3-3/4". My rims are 17X10. The 15s that were on it before barely cleared the steering knuckles. I went to a heim setup and the 17s allow this with no clearance issues.
 

Madgyver

Contributor
Bronco Madman
Joined
Jul 30, 2001
Messages
14,679
Hear it from one who has a bunch of 77s....

A stock unlifted 77 will have the best steering set-up for street driving of all the years the EB was available (IMHO). If you lift a 77, the factory inverted-Y set-up will have bump steer and create toe-in problems. The aftermarket 3-way adjustable linkage works OK (done that) but for the way I wheel, it wouldn't have lasted long with the stock size links.

Here is how I would do it again. Raise the trackbar mount on the axle and run it stock position on the frame. Adjust it to the height and centerline of the axle and frame at ride height. This can be done with the stock tracbar or an adjustable aftermarket one. Also keep the stock pitman arm but do a tie-rod over set-up with chevy 1 ton ends, this will compensate for the lift.
For the wheels go with 17"s x 9.5" with 2 1/2" backspacing, If not available then run what is availabe and use 1 1/2" to 2" wheel spacers to give more clear for the big tie-rod ends..
 
Last edited:

Dan76

Sr. Member
Joined
May 17, 2006
Messages
895
I lifted my 76 3.5" and had no bump steer and it had the inverted Y setup on it.
 
OP
OP
T

Tuff68

Full Member
Joined
Dec 27, 2005
Messages
325
Loc.
Hermitage, TN
2.5" lift

Thanks to all for the great info.
So from the replys it seems that I can run a small lift ( 2.5" ) with the standard steering setup and not have any problems ?
Also does lifting the rear by adding 2.5" to 3" long add a leafs affect the steering or does the steering only come into question when you lift the front end. The reason I ask is because I am looking at putting the 2.5" to 3" long addleafs on the rear because it has saged and is setting about 2" lower than the front and by adding the standard 2.5" lift the back would still be low. I would love to just get a new 2.5" leaf pack but can't come up with the $$$ at this time.
Or could I fit 33" tires under it with out any lift at all.
Thanks
 
Last edited:

fordtrucks4ever

Bronco Guru
Joined
Oct 8, 2006
Messages
1,280
Loc.
DFW
You may need to remove stock rear springs and disassemble them. Most likely you have some really sprung leafs or broken ones. You can find a set of rear leafs the same width and match side for side each leaf thats dead. Not the best way to go, but the cheapest. I have done it in the past to fix bad sagging problems. Got me back on the road without problems. May also be a way to salvage your leafs and be able to add-a-leaf to get the lift you need. This is just one way I have fixed bad springs more than one time without problems. Some people may think its dangerous or too much trouble that can afford to buy what they want. Just an option and others may differ.
 

Louie

Bronco Guru
Joined
Mar 29, 2004
Messages
1,805
I'll bet you a buck that someone down in TN has an extra set of 2.5" rear leaf springs laying around for sale cheap. Just post a part wanted ad here & keep an eye out in the for sale section. I'm thinking you could get that done for close to the same price as adding a leaf & would be a much better set up.
 
OP
OP
T

Tuff68

Full Member
Joined
Dec 27, 2005
Messages
325
Loc.
Hermitage, TN
Thanks again

Great information.
I will post an add for used rear leafs, I did not think there would be any of those around.
 

blubuckaroo

Grease Monkey
Joined
Jun 11, 2007
Messages
11,795
Loc.
Ridgefield WA
I'm using 3" positive offset 16" wheels (no low rider dish) on my '77 with a 2.5" lift and inverted "Y" tie rod steering. Works really good! If I hadn't used 16" rims, the tie rods would have been into the wheels.
 
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