Chasing Caster

[Otis Campbell]

I may be one of the “lucky” ones with a factory anomaly with respect to the caster in my Dana 44. I’ve got a 2.5” suspension lift 7 degree (because 4 wasn’t enough) C bushings, sleeves (1.5*) around the upper ball joint and still only have 3.5 degrees of caster. I’ve verified the installation of the C bushings is correct. Can this be????

I’m thinking about new radius arms or a cut and turn. It’s on center feel/ wandering is better than when I started but could still use improvement.

Lares power steering box. All new ball joints, tie rods and adjustable track bar.

Is this common?

 

[Shimmy]

yes! low caster is an issue on a lot of broncos. some say that the 77 had the best chances of good caster but i wasn't that lucky either. 3.5" SL, 7* bushings, JD long arms and i'm at 5.5* caster

 

[Otis Campbell]

yes! low caster is an issue on a lot of broncos. some say that the 77 had the best chances of good caster but i wasn't that lucky either. 3.5" SL, 7* bushings, JD long arms and i'm at 5.5* caster

I should have said in the original post that mine is a 71 - if that matters.

 

[Broncobowsher]

The math adds up. You started with an axle with very low caster, which is normal. Threw all the caster correction possible at it and took half of it away with lift. And you ended up with a caster number that many can only dream of.

If you want any more the best would be to undo what you put into it, to fix the U-joint angle. Then do the cut and turn to get the caster you really want.

 

[Otis Campbell]

The math adds up. You started with an axle with very low caster, which is normal. Threw all the caster correction possible at it and took half of it away with lift. And you ended up with a caster number that many can only dream of.

If you want any more the best would be to undo what you put into it, to fix the U-joint angle. Then do the cut and turn to get the caster you really want.

How does this look?

 

[toddz69]

How does this look?

I've seen worse! (example below from a vendor's build at Barrett Jackson last weekend).

Todd Z.

 

[lars]

How does this look?

That looks like a bit much. A view looking horizontally would be better. But measure it yourself. Knowledgeable folks here will advise that 1-2 degrees pinion down is ideal.

 

[jamesroney]

10.5 front axle to to frame gap. 10 inch rear axle to frame gap. (you people call this "3.5 SL")

Dana 44 factory low pinion. Factory zero degree bushings. Factory wedges in stock location. Track bar riser.

7 degrees of caster, and 0 degrees of driveshaft to pinion u-joint angle.

Drives like it should. At 70mph, in 2WD, I have driven with the hubs locked in, and literally couldn't tell the difference.

"cut and turn" , "Cut and turn..."

 

[lars]

<snipped>
At 70mph, in 2WD, I have driven with the hubs locked in, and literally couldn't tell the difference.

Me too. I've accidentally left the hubs locked in (or someone was messing with them) and didn't realize it until I happened to look at a hub. It was not always so.

Cue "cut and turn."

 

[ntsqd]

Cue "cut and turn."

"cut and turn" , "Cut and turn..."

This.

 

[Broncobowsher]

With 7° bushings I could tell if a front hub was locked at highway speeds. There was a bit of why is this doing something new before i realized it. But it was back to normal as soon as they were unlocked.

 

[Otis Campbell]

That looks like a bit much. A view looking horizontally would be better. But measure it yourself. Knowledgeable folks here will advise that 1-2 degrees pinion down is ideal.

I’m getting about 10* on the pinion and 18* on the driveshaft.

 

[ntsqd]

If I'm understanding this correctly that implies that the U-J is operating thru an 8° angle. I'm fuzzy on the number, but seem to recall that 2-ish° is what the U-J mfg's like to see as max for a drive-shaft in continuous service. If that were a rear shaft it would be way too much. Which circles back around to James' & Lars's posts.

 

[Broncobowsher]

I’m getting about 10* on the pinion and 18* on the driveshaft.

That sounds correct for 7° bushings.

I want to say Tom Woods has an offset U-joint that can run 10° without binding, but the tradeoff is the offset causes a vibration. Not an imbalance vibration. The offset causes the shaft to move on and off centerline. Fine for crawling, horrible at speed.

Cut and turn can fix the U-joint angle and give you whatever caster you want to dial in. You can keep the 7° bushings, just pull the cap off and flip the front bushing upside down and that makes it a zero degree bushing.

 

[Otis Campbell]

What does a "cut and turn" cost?

 

[jamesroney]

What does a "cut and turn" cost?

Great question! It all depends on your level of skill and ability. Also on your state of completion on your build. And how much you tolerate scope creep.

When you have the front end completely disassembled, cleaned, and prepared, the cut and turn is approximately 3 hours of labor for cutting, grinding, rotating, and re-welding the inner C.

If you drove a brand new Bronco into a shop for a cut and turn...I imagine it would be well over $3K to fix it and drive it back out. The biggest problem is the combination of trades required to do the job. You need a mechanic, a fabricator, and a welder. Basically a millwright. If you take it to a welding shop, they suck at axle work. If you take it to a mechanic, they suck at fabricating. If you take it to a Fab shop...they hate used, dirty crap. So it's a job that nobody wants to do.

Scope creep comes in when you say things like: "We might as well do the _______ while we are in there." Or someone says we should powder coat it.

There is no rational shop that is going to pull a 50 year old Dana 44 inner axle shaft and not install a new inner axle seal. Way too much warranty risk. So now you have to pull the gears. Nobody wants to pull a front wheel hub without servicing the wheel bearings. And inner axle u-joints. Proper welding requires pre-heat, so everything is going to get hot. There are exactly zero production welders that admit that your axle is sufficiently clean. And they get mad when you leave grease in your weld-affected area. So you have to cook that off.

But done properly, it's basically free, and the results are glorious.

 

[ntsqd]

There's an axle shop local to me that can hot tank a full size axle housing. That means a complete tear-down, but then you'll only get grumbling about welding dirty parts instead of vocal complaints. But it's LONG ways away from AL.

 

[TheLimeRanger]

What does a "cut and turn" cost?

$736.81 to be exact. I just had mine done at Mitchell Differential in Mass. I pulled the dana 44 and brought it to them basically bare with the exception of the gear set. They pulled the gears replaced the inner seals and the pinion seal and did the cut and turn. I went and picked it up and brought it home. I think James is spot on with his estimate of $3k to drive it in and drive it out.

 

[Otis Campbell]

Having a hard time finding anyone in Birmingham that will do it.

 

[ntsqd]

Are you looking for a auto repair shop to do it, or a fabrication shop to do it? Looks like you've got a lot of big fab shops in your area. I'd think that you're going to need a smaller shop to take on that project.