Tim's Bronco Build
Lead Driver
Joined: Jul 2017
Posts: 9,529
Likes: 1,144
From: San Jose, CA
The larger factory trackbar bracket that came on his '76 and '77 frames was sized to work with the Inverted-Y steering. It's practically long enough to be a dropped bracket on an earlier frame.
Lifting an EB of those years with the factory steering would still have called for using both a dropped pitman arm and a matching dropped trackbar bracket. Which were both different from the '75 and earlier models in one way or another.
Swapping the linkage to the earlier Inverted-T steering setup on the later frame skews the parallel part. It's not a huge problem to make them work together, but you need to mix and match parts because you've changed the overall geometry.
You still need to drop the angles with a 3.5" lift or the angles will be too steep. But dropping the normal ways will leave the trackbar and draglink at different angles.
If you use nothing your angles won't be parallel.
If you use a dropped trackbar bracket and standard dropped arm your trackbar's upper eye will still be too low to be parallel with the draglnk.
If you use a dropped pitman arm for an EB without the trackbar drop the draglink's upper end will be too low.
Whether you use both drops or only one, the angles are never quite perfectly parallel to each other if you use standard parts.
There are several ways to overcome that however. If using standard geometry T-style steering:
1. Replace the upper bracket with one from an earlier rig, or a custom made one to mimic the earlier frames. You might be able to re-drill the hole at the correct height, but I've never tried it so don't know how well the bracket plays with that idea.
2. Keep the stock upper bracket (that already has more drop than an earlier one) and use a pitman arm with less drop. Such as the one from a full-size truck.
3. Custom setup, including some or all of the following: Going tie-rod over, lower mount riser bracket, custom upper bracket, custom pitman arm, etc. In other words, fabbing up your own custom setup with either custom or off-the-shelf parts so that the two bars are as parallel as possible and pivot in as close to the same plane as possible.
The simplest is using the '78/'79 dropped arm:
With this you need to either use the correct upper draglink end to fit the larger tapered hole, or use a tapered shim to neck it down to EB size.
I used an F150 tie-rod and draglink with that arm on my '71 with disc brakes from a full-size truck.
In other words, there might be some mock-up to do to get it just right for the individual Bronco, but as long as you're aware of the main points you won't end up buying lots of parts you can't use.
If the front steering knuckles are from the earlier model, the tie-rod and rod ends are one size. If they're from a full-size truck, they're another size. And if they're from a '76 or '77 EB, then they're still another.
If you use an EB arm you need the right upper draglink end or ream out the hole. Or use a spacer sleeve if the hole is the larger size.
Or if you choose a certain draglink it will dictate what you need to do for a pitman arm hole.
It's actually much easier than all that writeup makes it sound like. You just have to know what all you're going to be mixing and matching so you know what choices you have to make when sourcing the parts.
If you use something non-stock geometry-wise (such as the GM 1-ton stuff), some of those things change. Hence the need sometimes to mock things up first to confirm the angles needed to make it right.
See? Like everything else... Simple.
Paul
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FTE Chapter Leader
Joined: Jan 2006
Posts: 21,161
Likes: 7,910
From: North Central Washington
Great project Tim. Almost at the "light at the end of the tunnel" phase even!
I didn't see if you mentioned it already, and I just Evelyn Wooded my way through because it's late and I'm not seeing straight, but figured I'd bring up the subject of the frame again.
Do you know what steering linkage you'll be using in the end? The '76/'77 frame you're using will dictate a custom mod or two with the steering linkage depending on what you're going to use. I figure you're doing a lot of custom stuff anyway, so this will be a very minor tweak. But curious what type of setup you'll be building?
It's not a huge deal, but with the larger trackbar bracket and the typically more popular (and stronger) "inverted-T" style steering linkages, your angles will be off if you use most of the off-the-shelf EB stuff.
Anyway, you may already have it all engineered. And you're not there yet anyway, so if not there'll still be plenty of time to work out the details.
Great how it's coming together.
Paul
I didn't see if you mentioned it already, and I just Evelyn Wooded my way through because it's late and I'm not seeing straight, but figured I'd bring up the subject of the frame again.
Do you know what steering linkage you'll be using in the end? The '76/'77 frame you're using will dictate a custom mod or two with the steering linkage depending on what you're going to use. I figure you're doing a lot of custom stuff anyway, so this will be a very minor tweak. But curious what type of setup you'll be building?
It's not a huge deal, but with the larger trackbar bracket and the typically more popular (and stronger) "inverted-T" style steering linkages, your angles will be off if you use most of the off-the-shelf EB stuff.
Anyway, you may already have it all engineered. And you're not there yet anyway, so if not there'll still be plenty of time to work out the details.
Great how it's coming together.
Paul
The grill is going to stay body color but the top, finder flares and bumpers will be different color.
