77 Conversion Steering Issue - Vertical Movement

[saxman]

Hola,
Its been a while since I have done some work! Good to be back! I know steering stuff is hard to track down. But I don't understand this vertical movement thing...

I removed the inverted Y-style linkage and installed a T-style kit that I purchased from Wild Horses a while ago. I was having no steering issues with the inverted Y. Just wanted to install something beefier. I have had this Bronco for 14 years now. First tie-rod modification.

I got everything put back together and drove around the neighborhood. The steering is a little sloppy. One thing I noticed is that when I am at a standstill, when I turn the steering wheel to the right, the front of the truck raises several inches. Actually, the entire tricks moves some, it moves so much that I am leaving tire marks on the concrete just standing still and turning the wheel. When I turn back to the left, there is no/minimal vertical movement. I am not sure why it is doing this?

Before I removed the Y style, I measured from tied rod bolt to tie rod bolt, and kept that dimension. However, I am not sure if I positioned the drag link bolt where it meets the tie rod correctly?

I do know that the drag link and trac bar should be parallel as much as possible.

Any thoughts suggestions? Will get some pics up in a bit.

Thanks.

 

[DirtDonk]

Some body motion is normal with these rigs, especially when modifying the steering. But less is obviously better.
Is your tie-rod rotated up so that the draglink end mounts at roughly a 60° angle? This gets the zerk fitting pointed up towards the radiator or thereabouts.
It also helps to keep the pivot points working in the same planes.

But here's the question. Did you install a dropped pitman arm when you did the conversion? You need to, or nothing is going to align.
You're changing the steering geometry from stock, so you have to make sure to compensate in areas that have had their relationships altered. Your '77's trackbar bracket on the frame end is much larger than the earlier ones where the T-style linkage was stock. So you need to keep the stock trackbar bracket, but add a dropped pitman arm because your new draglink is at nowhere near the angle of the old one.

And more often than not, you don't use the normal dropped pitman arm. They drop too much most of the time. For most '77's then, you'd use one like the one pictured here for the full-size Broncos: http://www.wildhorses4x4.com/category/s?keyword=pitman+arm
See the difference?

The problem then becomes the upper end of the draglink is too small for the new larger hole in the pitman arm. I have not tried them, but the shims for the tie-rods might work just as well here. I think the #2382 would work. Maybe some that have already gone down this road will chime in to let us know how theirs worked out. I've sold similar setups to several members here, so hopefully they'll see the discussion.
Don't remember if the common solution was to use a larger upper end, or the sleeves to neck down the hole.

And truth in advertising here, the full-size pitman arm is indeed twisted the wrong way for an EB. But with 2.5" of lift and if you're not doing any serious jumping and crawling, you'll be fine.
I've got about 40k mile son my similar setup.

But for sure make certain that your tie-rod is twisted up to the appropriate angle and that you didn't install a trackbar drop bracket.

Paul

 

[saxman]

Ok, the zerk fitting is pointed down around 20 degrees. I understand about the angles of the trac bar and drag link. Let me get the zerk angle corrected and report back. I assumed that I could keep the stock pitman arm. The angles looked pretty good last night.

The link you sent did not include a picture of the full size-bronco Pitman arm, can you resend. Thank!

-Sax

 

[surfer-b]

One thing I noticed is that when I am at a standstill, when I turn the steering wheel to the right, the front of the truck raises several inches.

That is normal for a vehicle to do that. That is the SAI at work. When you turn the steering, because of the SAI, it rotates the spindle down, its trying to push the tire down but it cant go down so the vehicle will raise in the front, then when the steering wheel is released the weight of the vehicle pushes back causing the spindle to return to its highest point which is center. This is the effect of self center steering, which keeps it from drifting all over the road. Now, you may have other things going on but for a vehicle to raise up when the steering is turned is normal.

 

[blubuckaroo]

It's caused by the steering axis inclination.
https://www.youtube.com/watch?v=IUcZ63unEyU

I also replaced the "Y" steering with a "T" setup from Wild horses. I ended up using this pitman arm to stop the bump steer.
http://www.wildhorses4x4.com/product/Drop_Pitman_Arm_7677yr/Bronco_Pitman_Arms

Actually, hadn't noticed the bump steer until I swapped the auto tranny for a manual. Whenever I made the shift and the car's nose dipped, it would try to change lanes.

 

[DirtDonk]

Ok, the zerk fitting is pointed down around 20 degrees... Let me get the zerk angle corrected and report back.

Sounds good. That angle shouldn't have ended up with good angles at all, but hey, you never know with these things!
Basically though, the biggest reason for rotating it up is not that it helps correct the angles (which it does) but is about reducing the amount of rotational force applied to the tie rod by the drag link.

I understand about the angles of the trac bar and drag link.

In the case of the aftermarket stuff with the "bent" drag links, make sure to use an imaginary line between the pivot points, rather than some general point of the bar itself.
You may already be doing that, but it does skew things visually to have those kinks in the bar.

I assumed that I could keep the stock pitman arm.

Nope. Based just on the 2.5" you lifted the suspension, then you would often keep the stock pitman arm. But you changed the whole geometry by changing from a Y to a T. This is why people with '76 and '77 EB's need to go with a pitman arm drop.
Unfortunately most of the dropped arms for EB's have a little more drop than they need. It's possible that an EB arm would work, but this full-size Bronco arm generally turns out better.
As always though... "Your results may vary" carries the day.

The angles looked pretty good last night.

Surprising, but not impossible. Just that most would not. Yours could be different even though they shouldn't be. But as said, you never know until you get it done.

The link you sent did not include a picture of the full size-bronco Pitman arm, can you resend.

OOps. I'll go back and correct that post too. Guess my copy-n-paste kung fu was weak last night.
http://www.wildhorses4x4.com/category/s?keyword=pitman+arm shows the different arms. You would usually use the shallower #791275, but I'm showing them all to note the difference better.
http://www.wildhorses4x4.com/category/s?keyword=tapered+sleeves shows the different sleeves. The tapered hole in the new arm is larger than one for a '76 or '77 Bronco. So you either need an upper rod end with a larger taper, or take up the space with the sleeve.
If it turns out that a #1288 would work for you though, that would be an even better option. Maybe buckaroo can post up a pic of his straight on, to see what his is like and compare to yours.

Paul