Another Caster Question...

[Torkman66]

Today was the first time I was able to get the Bronco out on the highway. It ran very nice. Only issue was that is was all over the road...very touchy left to right. So, as I have learned with several other restorations, it is the castor. I just dont understand how or why it is so bad. Here is my setup. Maybe I did something wrong???

2.5" SL
No body lift
7* Bushings
33" tires
New power steering system from steering wheel to tires.
All was purchased new through WH

A couple things that might help figure this out. I installed the 7* bushings and arms on the frame with no engine or body mounted and tightened everything to specs. Did that make a differance having no weight on the suspension?

I also have about 4" of steering wheel travel (when sitting parked) before the steering box engages...seems excessive. New box.

I have checked and rechecked that the C bushing are installed correctly. Raised section on bushing on front bottom, top rear both sides.

I even installed the ball joint sleeves which are suppsed to give me 1* but they did not seem to make a difference.

I know the correct way to do this would have been to cut and move the Cs...did not happen and axle is now finished.

So, seems like a simple 2.5" lift and 7* C bushings along with 1* balljoint sleeves would get the castor close enough to drive pretty good.

Has anyone else had to install lowering arms to get castor in specs with only a 2.5" lift?

Ideas or suggestions?

 

[serial car restorer]

What is your toe setting? Too much toe-out will do that also.

 

[Torkman66]

Well, that is interesting. I sure can mess with that a bit. I was shooting for 1/4" TI but remeasured and noticed it is closer to 1/2" . Would be easy enough to change it and see if that helps.

 

[hsach]

I would get some real numbers from an alignment shop to see where you are at. If you need more caster at this point, you could try T-Rex arms from Duffs. They come with some caster built in.

I just checked the T-Rex arms, they come with 4.25 Degrees of caster built in. Not sure how much that will translate to overall Caster numbers, 1 to 1 ratio or not, but it will positively increase the caster.

 

[Oldtimer]

Tire age (not tread depth) and air pressure can make a difference.

 

[Torkman66]

New tires. 25 psi.

 

[ford man]

4" back and forth in steering seems a little bit to much .Also did you tighten the ball joint sleeve to tight ?1/2 in toe in will hold the road if it was strait or out it could be a problem.

 

[Bruners4]

Could the C bushings be installed backwards and decreasing the caster?

 

[Torkman66]

That was my first thought. I have checked closely and they sure appear to be installed right. The lower front bushings have the enlarged thickness nubs and the rear top have the enlarges thickness nubs. I did not grease the bushings, just put it all together at the frame restoration stage. Wonder if the bushings somehow are not setting the arms right, are too tight and somewhat out of place. Worse comes to worse I could remove them and re-install (lots of work). I think the first thing to do is to go get the alignment numbers and actually see where I am. The pinon is slightly above the 90 degree angle suggesting near zero or negative caster. I thought it would need to be slightly below the 90* angle.

 

[Brush Hog]

Double check all the nuts and bolts on steering and suspension components. Could be something loose. Including leaf spring shackles. I’ve learned just one nut a little loose can make steering and handling very sloppy.

 

[toddz69]

Well, that is interesting. I sure can mess with that a bit. I was shooting for 1/4" TI but remeasured and noticed it is closer to 1/2" . Would be easy enough to change it and see if that helps.

Get it double-checked at an alignment shop and if you're truly running that much toe-in, that could be part of the problem. I've had two cars that came to me with excessive toe-in on purchase and they were quite darty.

Todd Z.

 

[Broncobowsher]

4" back and forth in steering seems a little bit to much .Also did you tighten the ball joint sleeve to tight ?1/2 in toe in will hold the road if it was strait or out it could be a problem.

But is that with the engine running or off? There will be play in the steering wheel with the engine off as the spool valve goes to the travel limits before the mechanical limits come into play.

While looking at things, is the steering box tight to the frame. Is the frame flexing (cracked)?

25PSI is a bit light. Try closer to 30 and see what that does.

Also want to see actual alignment shop numbers.

 

[Torkman66]

You guys rock!
Engine off. I'll check play when engine running.
Box bolted tight, frame not cracked...will triple check tomorrow.
Will increase PSI.

I originally did the tape measure from front tread to front tread and then rear tread to rear tread to check for initial toe in. It was close. Tonight after focusing more attention on the toe in from this thread, I went out and started by ensuring the steering wheel was exactly in the center of stop to stop turn. Interestingly the steering wheel was exactly in the right straight ahead position (I got that right). I set up the string method from behind rear tire to ahead of front tire. Meticulously got the string exactly parallel to the rear wheel. Did that on both sides. Result...

Driver side tire was toed out 1/2". Passenger side tire toed in 3/4". First, that explains why there was a slight wheel turn to the right in order to go straight down the road. However, given they were both headed left, seems like when I would drive and turn wheel slightly right to compensate the tires would then be close to correct toe in.

Anyway, in the morning I will make all the adjustments to toe in to get it very close to 1/8" to 1/4" total. I'll take it for a drive and report back.

I did note that my pinon, while pointing slightly up from horizontal is at an angle less than the drive shaft. I'll measure both angles exactly in the morning and report back.

 

[Beau Nugget]

My ‘75 drove horribly. Much the way you describe yours. A new set of tires and a proper toe in adjustment made it drive like a dream. It had quite a bit of toe out to start with. I wouldn’t have believed it would make such a difference

 

[Torkman66]

@beau, man I hope fixing the toe in does it. The tires are new...I'll get on it first thing in the morning and let you all know what happens.

 

[ntsqd]

I'll be the first to say it outright, if you want it to drive like a modern vehicle a cut-n-turn is very likely in your future.

Most alignment shops are going to look up the Caster spec from when it was a new vehicle. Toss those out as no longer relevant. Look up what Lars has had to say about what the Caster needs to be now.

 

[Broncobowsher]

Measuring tread block will not work for setting toe. The blocks are different shapes and sizes. Even if they look the same, the make them slightly different to break up the harmonics. And there is a little variation in the molding as well.

To use tread blocks, measure at the back the best you can and mark the exact blocks you hook the tape measure on. I just use some masing tape. Now roll it forward so the tape is about the same height off the ground, measure again. This will get you an apples to apples measuring points and account for as many variables as you can do in your driveway. It will even work with a bent rim.

 

[Apogee]

Another relatively easy way to measure toe would be to clamp a 2x4 or piece of angle iron horizontally to the tires, measure front, measure rear and adjust accordingly. If you don't have dust shields, it's something you can do off the rotors instead with just as good results. Measure roughly at your tire radius for best results.

 

[Shimmy]

^ i did something similar to this. took the tires off and used a trued piece of wood secured thru the lug holes. very easy to measure toe that way.

 

[Torkman66]

Took time to set up a nice string system. Not perfect but it did identify a toe in misalignment. Passenger front toe in was 5/8". Drivers was 1/2" toe out. Seems like my initial setup was actually close but had wheel turned slightly. With wheel straight, fixed toe in to 1/4" total.

Also, measured my driveshaft angle at 17* and my pinon at 9* for a pinon angle of 8*. Probably the max even for a street driven Bronco. Given the 2.5" lift, that tells me that my 7* C bushings are likely doing what are are designed to do or the pinon angle would be worse. Thoughts?

I took it out for a drive and while I noticed some improvement, it is still wondering and when you hit a bump in a turn, you have to be paying attention...clearly not good.

So, while cutting turning the Cs is the ultimate solution, that is a problem with a completely finished and powder coated Dana 44. Considering this is a street only driver, what are the next best options to get this thing tracking and stable? I'm arranging to take it to an alignment shop to get a printout so I know what I am dealing with.

Some pinon angle pics: