More Caster/Alignment/drivability ideas?

[Torkman66]

Folks, as you all know I have been a OP on a few fairly long and super helpful threads regarding caster/alignment issues. One more (maybe the last) question for you all to ponder.

As most of you know, I have a completely restored 72.
WH 2.5" SL (no BL)
33s
All new steering components
WH quick ratio PS system (included new steering shaft as well)
IDIDIT column
7* wedges
Eccentric Ball Joint inserts
Caster is 4.3* both sides
Toe-in is .2 total

However, driving this weekend again made me think this cant be right. I seriously would not want my wife to drive this thing. Its fine going straight down the road, but on a curve or going over a dip while in a curve it could easily cross the center line if you weren't double gripping the wheel.


Many suggest caster at 4.3 should be just fine. I'm thinking based on how it drives it should be more like 8*.
I know I should have cut and turned the Cs, too late. I can install lowering radius arm brackets?
It just seems like the steering is way too responsive. Like I wished the steering box had a way to "tighten" up the action...could the WH quick ratio box just be too reactive?

I'm at a loss here but need to try something...only thing I can think of that would be fairly easy is to weld on the lowering brackets. Thoughts/ideas?

 

[serial car restorer]

WH 2.5" SL (no BL)
33s
All new steering components
WH quick ratio PS system (included new steering shaft as well)
IDIDIT column
7* wedges
Eccentric Ball Joint inserts
Caster is 4.3* both sides
Toe-in is .2 total

This seems like a pretty basic config. I've got to think that someone else has the same setup, or at least very close. Which makes me think that other people would have the same complaints. Since we don't hear from everyone with a 2.5" and 4-turn steering, I've got to wonder if there is something that we are missing or overlooking. But I'm having trouble figuring out what it could be...

Or are everyone else's rigs driving like yours, but they just accept that that is how early Broncos drive? I hope that's not it.

Makes me wonder what mine is going to drive like once I get it back on the road. I've got old-school ~3" SL and plan to put 4-turn power steering as well. Probably replace the C-bushings with 7° since I have no clue what's in there now.

 

[BUCKWILD]

My only thought was these are utility vehicles not ever built to Handel well and probably wont handle well. I also believe the quick ratio boxes make them to sensitive and magnify a already poor handling vehicle. We forget they never handled well and now we want them to handle like a modern vehicle and I dont beleve the will. drive them and enjoy is is a drive you have to pay attention but still enjoyable. Just my thought on this matter, you have taken steps to make it handle better than the factory ever did 60 years ago.

 

[1969]

Cut and turn your knuckles to get more caster.

 

[gr8scott]

I've got to think that someone else has the same setup, or at least very close.

Mine is similar except:

WH 3.5" SL, no BL
31s
Stock Column
Trackbar drop bracket
Drop pitman arm

Unsure of caster, but my steering returns to center when coming out of a turn. No idea of toe-in.
I bought the same WH steering kit some 15-20 years ago. Steering is super sensitive, steering damper has no effect.

but they just accept that that is how early Broncos drive? I hope that's not it.

That's it. I just got used to it. My son drove it for the first time some time ago and said "what's up with the steering?"

 

[LUBr LuvR]

What size is your steering wheel? Stock 2 spoke? With an IDIDT column, likely a smaller aftermarket/custom? Smaller diameter wheels can make the steering feel faster or “twitchier”.

My ‘74 has a 2-1/2” SL of unknown/1980’s pedigree, no BL. When I had the worn out steering box rebuilt to a 4 turn, it was a really noticeable difference in handling. I had definitely thought about replacing the existing 14” steering wheel, but got used to It. While sensitive, it doesn’t handle badly - but nothing like a stock rig with a 6 turn and oem wheel.

Have you double checked all bolts, linkages etc are tight? Might be worth trying a larger steering wheel, and see if that tames the sensation.

 

[Torkman66]

All great ideas and considerations. Appreciate it. I may just need to live with it.

 

[lars]

Cut and turn. Just do it. I know it's painful. Temporarily. Once it's done and you drive it, you'll forget all about the pain. @jamesroney and I don't agree on everything but this is one thing we are both adamant about- anything else is a crappy bandaid, one with lousy adhesive. I have driven several Broncos that "drive great!" Uh, no. Better than a box stock '68 with manual everything maybe, but terrifying compared to most new vehicles. I'm at about 6.5°, would be awful with manual steering but in spec for a 1978 Bronco that came stock with power steering and has no such handling issues.

 

[Broncobowsher]

...

However, driving this weekend again made me think this cant be right. I seriously would not want my wife to drive this thing. Its fine going straight down the road, but on a curve or going over a dip while in a curve it could easily cross the center line if you weren't double gripping the wheel.


Many suggest caster at 4.3 should be just fine. I'm thinking based on how it drives it should be more like 8*.
I know I should have cut and turned the Cs, too late. I can install lowering radius arm brackets?
It just seems like the steering is way too responsive. Like I wished the steering box had a way to "tighten" up the action...could the WH quick ratio box just be too reactive?

I'm at a loss here but need to try something...only thing I can think of that would be fairly easy is to weld on the lowering brackets. Thoughts/ideas?

I'm reading that as the caster is acceptable.
What you describe is issues with bump steer and roll steer.
I know the 2½" lift isn't much, but I still see steepish drag link and steering angles. While this is good for traditional bumpsteer, there is another bumpsteer (I don't know if there is a special name for it) where the front axle shifts side to side. What actually happens is the axle tracks straight, but the frame and body bob side to side as the front suspension cycles up and down over the dips. Roll steer is when you get some body roll the axle(s) shift position and induce steering action. Particularly noticable on the rear axle.
The softer the springs, the better the ride, but the more the suspension cycling issues show up.

 

[Shimmy]

^ this is what i'm thinking too. go over some speed bumps and see how much your steering wheels moves (L/R). Your caster could be more, but based on what you describe in your post, i'd focus on your steering angles now. you'll read folks stating that your tie rod and track back should be parallel. thats not completely accurate. They should follow the same arc angle and be nearly shadows of each other. I'm sure there's better ways to explain it, but The more flat your TR and TB are, the less bumpsteer. OTK and TR relocation bracket (axle side) maybe in your future?

 

[Quick & Dirty]

One issue with increasing caster is increased wear on the outside edge of the tires. The Bronco steering arms don't have enough angle for proper Ackerman, so the tires scrub on tight turns. Caster angle changes camber in a turn. The more you have, the more pressure it puts on the edge of the tire.
If the steering returns to center, and doesn't wander on straights, you don't need more caster.

 

[serial car restorer]

The softer the springs, the better the ride, but the more the suspension cycling issues show up.

So you are implying that my old school stiff springs will ride worse, but might steer better?

 

[Broncobowsher]

So you are implying that my old school stiff springs will ride worse, but might steer better?

Yes. Since the suspension gets locked up, there are no issues with travel related geometry. Your filings may fall out and you may have internal injuries from driving over a steel plate covering the road.

 

[fishinman78]

Folks, as you all know I have been a OP on a few fairly long and super helpful threads regarding caster/alignment issues. One more (maybe the last) question for you all to ponder.

As most of you know, I have a completely restored 72.
WH 2.5" SL (no BL)
33s
All new steering components
WH quick ratio PS system (included new steering shaft as well)
IDIDIT column
7* wedges
Eccentric Ball Joint inserts
Caster is 4.3* both sides
Toe-in is .2 total
View attachment 942063

However, driving this weekend again made me think this cant be right. I seriously would not want my wife to drive this thing. Its fine going straight down the road, but on a curve or going over a dip while in a curve it could easily cross the center line if you weren't double gripping the wheel.


Many suggest caster at 4.3 should be just fine. I'm thinking based on how it drives it should be more like 8*.
I know I should have cut and turned the Cs, too late. I can install lowering radius arm brackets?
It just seems like the steering is way too responsive. Like I wished the steering box had a way to "tighten" up the action...could the WH quick ratio box just be too reactive?

I'm at a loss here but need to try something...only thing I can think of that would be fairly easy is to weld on the lowering brackets. Thoughts/ideas?

My 76 was the exact same way... driving straight no problem, go into a corner or hit a dip in the road and hang on. I felt the same way you did. Felt like I could drive it, but was nervous for anyone else to drive it.

Tom's Offroad 2.5" lift with adjustable track bar and the factory 4 turn box with three way adjustable tie rods

I did three things that dramatically improved the handling
1-Hellwig Front Sway Bar
2-Duff T Rex Arms (built in caster)
3-Drop Pitman arm

It drives soooo much better now! Honestly, I did the drop pitman arm last and it made the most difference, the T-rex arms and sway bar were just a bonus and made it ride better.

The current Bronco I am working on I decided to do the track bar riser bracket to get the track bar more parallel and I am installing the tie rods on top of the knuckle, we will see if that makes this one drive any better.

 

[1969]

I did three things that dramatically improved the handling
1-Hellwig Front Sway Bar
2-Duff T Rex Arms (built in caster)
3-Drop Pitman arm

1. Stiffened your suspension to keep it from articulating as much. So geometry isn’t changing as much.

2. Added caster

3. Corrected your steering geometry, or made it closer.

 

[ford man]

Have you thought about this your ball joints might be to tight or need replaced?

 

[Broncobowsher]

My 76 was the exact same way... driving straight no problem, go into a corner or hit a dip in the road and hang on. I felt the same way you did. Felt like I could drive it, but was nervous for anyone else to drive it.

Tom's Offroad 2.5" lift with adjustable track bar and the factory 4 turn box with three way adjustable tie rods

I did three things that dramatically improved the handling
1-Hellwig Front Sway Bar
2-Duff T Rex Arms (built in caster)
3-Drop Pitman arm

It drives soooo much better now! Honestly, I did the drop pitman arm last and it made the most difference, the T-rex arms and sway bar were just a bonus and made it ride better.

The current Bronco I am working on I decided to do the track bar riser bracket to get the track bar more parallel and I am installing the tie rods on top of the knuckle, we will see if that makes this one drive any better.

1) helps reduce body roll, and roll steer
2) also reduces roll steer. The longer, more horizontal radius arms have less for/aft travel of the axle as the suspension travels.
3) alone it shows that track bar and drag link angles were incorrect to start with. Drop pitman arm changes the drag link geometry. which may be more correct, but if not correctly paired to changes in track bar geometry can make for worse handling.

 

[Apogee]

My '77 has always driven pretty well, but I did notice the lateral motion with suspension travel much more significantly when I went to softer springs up front...it's kinda weird to hit a bump and feel the body move sideways, but without any significant bump steer.

In it's latest iteration, I'm swapping in full width F150 axles, so I was able to increase the track bar and drag link lengths by a good 12.5" from ~28.5" to ~41". My goal was to get things as long and flat as possible, and they are basically horizontal at full stuff. In the real world, this means that the total lateral movement of the front axle for the top 6" of up-travel from ride height with 12" shocks is about .44", whereas for the bottom 6" of down-travel will be about 1.35" due to the position of the arc within the range of travel. The shorter factory track bar resulted in larger lateral movements of .64" and 2.01" respectively for comparison. We'll see when I drive it how much improvement it actually is, but the numbers look good to me.

That said, I've never had an issue with the quick ratio '77 EB steering box feeling too quick, even when it only had 3.5° caster, and I run a smallish Ø13" steering wheel as well. I sacrificed my front pinion angle to get a little more caster (6.5°) in the '77 EB when I upgraded to long-travel radius arms, since I didn't want to go through the effort of cutting and turning the knuckles, and now 20 years later, I'm finally cutting and turning the knuckles to get the best of both worlds with my axle swap.

FWIW, I run drop radius arm brackets on my '77 F150, and it drives super nice and has no driveshaft angle issues. I haven't had any major issues catching the radius arm mounts off road, though they have seen a stump or two in their day. That said, the design of the ones I have share the transmission cross-member bolts, making trans removal a much bigger PITA that it was before those drop brackets were added.

Tobin

 

[Brush Hog]

I’m no engineer or physicist. heck I only got the job I had because there were no math questions on the entry exam. That being said is there any chance that new power steering pumps are too strong/efficient when combined with close ratio steering boxes (or new steering boxes). I swear even sitting in my garage with engine running a breeze on the steering wheel will move the tires slightly.

 

[1969]

I’m no engineer or physicist. heck I only got the job I had because there were no math questions on the entry exam. That being said is there any chance that new power steering pumps are too strong/efficient when combined with close ratio steering boxes (or new steering boxes). I swear even sitting in my garage with engine running a breeze on the steering wheel will move the tires slightly.

That means you need bigger tires haha!