Dana 44 disc conversion spindle help.

[FordFanStan]

I purchased a used 73 Bronco recently that came with a 25-30-year-old (but new) Duff disc brake conversion kit for the Dana 44, and I'm running into an issue putting it together. I believe the kit uses a 77 Bronco knuckle and spindle, or possibly a similar year F-100. When I tighten the spindle nuts on the driver's side with the short shaft, things seem ok, but the shaft is just nearly touching the center pin in the diff. When I tighten the spindle nuts on the passenger side with the long shaft, it sucks the axle in tight, yet there is still ~1/8" open space in the diff, forcing the knuckle to steer left, and I cannot move it by hand. I did not install slingers on the inside axle shafts (against the axle tubes) because every thread I found here on ClassicBroncos and a YouTube video from Wild Horses never shows them installed there. But maybe that is my issue, because the attached page from a manual I found online shows there should be one.

The large seals against the slingers are installed with the flat side against the slingers.
The thrust washers are installed with the bevels toward the slingers to accommodate the axle radius.
The small seals are installed with the flat side against the bearing, as per the majority of the info I can find online.


https://photobucket.com/share/2cddb147-0095-4842-9995-8681d3c8e46a
https://photobucket.com/share/a7813993-e34b-4839-b697-5581932320ae
https://photobucket.com/share/ea0c3e96-5bb1-45f2-965e-c694c8b9bc30
https://photobucket.com/share/4704a4ee-dcc5-48ba-81b3-2c67c2dc7d21
https://photobucket.com/share/17674e7f-8452-48a4-82e7-52bf7ac1110c

 

[DirtDonk]

Since you have one together and working, presumably you’re doing them the same way. But are you making sure that the brake caliper bracket is going on before the spindle?
And you’re sure it’s a Duff kit, using Ford calipers? It’s all in a Duff box, or something like that?
What axle shafts? Stock original?
Sorry, I guess I should actually look at the pictures before I reply!
I’ll do that now…

 

[DirtDonk]

Interesting. Your diagram shows the spindle going on the knuckle first, then the shield and bracket after.
I believe this is incorrect and can easily be verified by how deep the spindle register is. If it’s deep enough to encompass the caliper bracket and still fully insert into the bore of the knuckle, then that should answer this question.
Of course, I could be wrong and I usually trust the books. And I don’t have one handy to confirm your particular diagram.
Where was that one taken from? Ford book? Aftermarket book? Specific year?
Mistakes happen of course. Mostly with me! But sometimes with factory drawings as well.

 

[FordFanStan]

So I am not 100% sure, but the previous owner told me he bought everything from Duff, and some parts, as well as packaging, were Duff-branded. 5-lug spindles, factory Ford calipers, 30-spline shafts.
I installed it in the order of spindle>dust shield>caliper bracket, as per the diagram I found here on CB. I had to find a diagram with factory disc brakes because I purchased the 73 Ford shop manual, which does not show the Bronco disc-brake setup. In my 73 Ford shop manual, it shows spindle>shield>bracket order on the 8-lug disc brake diagram. In the Chilton and Haynes manuals, it also shows that same order on the IFS Dana 44. But I am certainly not against trying to redo it in a different order if that sounds wrong. I'm not sure I understand your comment on verifying the depth with the caliper bracket and into the bore of the knuckle.

 

[FordFanStan]

Well, I continued looking online and came across this YouTube video. It uses a Duff kit and looks like the same spindles, caliper brackets, and calipers as mine. He installed them with the bracket first, as you stated. I will try that soon and see what the outcome is.

 

[DirtDonk]

Whew! With all the books disagreeing with my memory, I was starting to question my sanity.
Well, I can still question my sanity, but at least my memory agrees with someone else's.

Reason I remember it this way, is I actually tried it that way once, and it was immediately apparent that it was going to jam the axle shaft down. So did it the way I originally did, and it worked out fine.
By the "depth" of the spindle vs the bore of the knuckle, I meant to check the amount of spindle behind the bolting flange. If it's deeper than the casting of the knuckle is, and would therefore sit proud in the back, then it's intended to have the thickness of the caliper bracket sandwiched in-between.
And for comparison, I'm pretty sure that the GM conversion does the opposite. With the 6-bolt spindles with shallow "register" (the part that "registers" with the hole in the knuckle) the caliper bracket/dust shield is intended to mount outside the spindle.

I'm never sure I'm using the term "register" correctly with things like spindles and rear axle shafts. I guess I’ll have to look it up one of these days!

 

[jamesroney]

Whew! With all the books disagreeing with my memory, I was starting to question my sanity.
Well, I can still question my sanity, but at least my memory agrees with someone else's.

Reason I remember it this way, is I actually tried it that way once, and it was immediately apparent that it was going to jam the axle shaft down. So did it the way I originally did, and it worked out fine.
By the "depth" of the spindle vs the bore of the knuckle, I meant to check the amount of spindle behind the bolting flange. If it's deeper than the casting of the knuckle is, and would therefore sit proud in the back, then it's intended to have the thickness of the caliper bracket sandwiched in-between.
And for comparison, I'm pretty sure that the GM conversion does the opposite. With the 6-bolt spindles with shallow "register" (the part that "registers" with the hole in the knuckle) the caliper bracket/dust shield is intended to mount outside the spindle.

I'm never sure I'm using the term "register" correctly with things like spindles and rear axle shafts. I guess I’ll have to look it up one of these days!

Yeah, you are right, and he is missing something big.

The "oops I put the spindle together backwards" doesn't work because the axle shaft u-joint yoke binds up against the inner C. (Technically the axle tube inside the inner C...but you know what I mean.)

So when you try to button up the spindle, it does exactly what everybody is talking about. (binds, tries to steer the knuckle, etc.)

BUT his photo shows an inner axle that is still about 3/8 of an inch short. If the axle shaft end forging is shoved up against the inner C...then the shaft should be bottomed against the carrier cross pin.

So I'm gonna say that the axle shaft is too short. Somebody tried to make it longer by reversing the spindle and the caliper mount. But then it started to bind at the yoke. So then they posted on Classic. My guess is that they only did one side that way.

Yes, you are using the term "register" correctly, and yes...the GM / Delco Moraine caliper mount does not register on the knuckle. The 6 bolt caliper mount registers on a machined shoulder on the outside of the spindle. The Kelsey Hayes caliper 5 bolt caliper mount registers on spindle to knuckle interface.

So when the OP puts it together correctly, he will need to check the axle shaft to spider gear engagement again. If I'm right, the axle will be short. If I'm wrong, that's great for him.

I did a cut and turn once where I put the inner C flush with the end of the axle tube. Since it was a HP44, I shortened both tubes and didn't have the old weld to reference. Not the dumbest thing I've ever done...but it was dumb enough. I will never understand why MIG welding is so easy. All MIG machines should have an alarm and shock collar whenever you attempt a finish weld. Or maybe an "undo" button.

 

[DirtDonk]

Ooh, an "undo weld" button!
Definitely needed.

Paul

 

[FordFanStan]

Thank you, @DirtDonk

the axle shaft u-joint yoke binds up against the inner C.
So when you try to button up the spindle, it does exactly what everybody is talking about. (binds, tries to steer the knuckle, etc.)

Well, I got this Bronco all in pieces. I did not disassemble it, and no instructions were included with these old/new parts. I only had the manuals and whatever I could find online to go off of. You are right in that the inner-shaft yoke is tight up against the axle tube, and it makes sense after reading this that it would force the knuckle to turn when tightening down.

So I'm gonna say that the axle shaft is too short. Somebody tried to make it longer by reversing the spindle and the caliper mount. But then it started to bind at the yoke. So then they posted on Classic. My guess is that they only did one side that way.

So when the OP puts it together correctly, he will need to check the axle shaft to spider gear engagement again. If I'm right, the axle will be short. If I'm wrong, that's great for him.

Both sides are installed the same. I have not tried installing them in the opposite order yet, so I do not know if the shaft will be short. I will know in the next day or two when I reverse the order and see what happens.

 

[jamesroney]

Thank you, @DirtDonk


Well, I got this Bronco all in pieces. I did not disassemble it, and no instructions were included with these old/new parts. I only had the manuals and whatever I could find online to go off of. You are right in that the inner-shaft yoke is tight up against the axle tube, and it makes sense after reading this that it would force the knuckle to turn when tightening down.

Both sides are installed the same. I have not tried installing them in the opposite order yet, so I do not know if the shaft will be short. I will know in the next day or two when I reverse the order and see what happens.

Well, sure. Believe me that I've put them together every possible wrong way.

It's easy enough to chop off the one that's touching the cross pin. But DON'T. I have a hunch it will end up exactly where it is supposed to be when you put the snap ring on the locking hub later. For the purpose of my sanity, I call that rubber thing that rubs against the spindle the dust boot. I call it that, because there is another thing called a "seal" that occupies the same space in the 1971 only Bronco Dana 44. There is also the little lip seal that runs against the spindle needle bearing. Then there's the wheel seal. So there are four things called "seals" in the same place. So I'm calling the dust boot a dust boot. When you install the drive flange, it pulls the stub shaft outward about 1/8 inch, and puts a little tension on the dust boot. That will pull the splines back away from the cross pin. So no problem there.

But the other one bugs me when you say it's binding in the knuckle / spindle...and it isn't even bottomed against the cross pin.

If both sides are the same, you did it in the right order. No need to take apart the "good side." As long as your spindle nuts are touching the spindle...you did it right.

 

[jamesroney]

So the "dust boot" is the 3132 in your pic. The slinger 3C132 is usually not used with an aftermarket forged axle shaft. I would have to see the end forging to know whether it wants the 3C132 or not.

 

[FordFanStan]

I rushed home after work, anxious to swap the order. I reinstalled as caliper bracket>brake dust shield>spindle.
Now the knuckles turn freely with only minor resistance (new ball joints). As far as spacing, it backed off both axle shafts about another ~1/16".
The driver's side has about ~1/16" of space between the end of the shaft and the carrier cross pin.
The passenger side has about ~3/16-1/4" of space between the end of the shaft and the carrier cross pin.

https://photobucket.com/share/2a0d0ac1-7dfd-4880-b34c-04b7bfb31278
https://photobucket.com/share/49d892e8-8af6-4bf0-8285-117ee2f3ed1c

As far as slingers, the passenger side is probably supposed to have one. The driver's side looks like it has one integrated into it. Would it hurt to run without? Just more risk of getting debris in the tube?

https://photobucket.com/share/ea819f14-5b35-43ce-9673-e2c98a4d0514

 

[jamesroney]

I rushed home after work, anxious to swap the order. I reinstalled as caliper bracket>brake dust shield>spindle.
Now the knuckles turn freely with only minor resistance (new ball joints). As far as spacing, it backed off both axle shafts about another ~1/16".
The driver's side has about ~1/16" of space between the end of the shaft and the carrier cross pin.
The passenger side has about ~3/16-1/4" of space between the end of the shaft and the carrier cross pin.

https://photobucket.com/share/2a0d0ac1-7dfd-4880-b34c-04b7bfb31278
https://photobucket.com/share/49d892e8-8af6-4bf0-8285-117ee2f3ed1c

As far as slingers, the passenger side is probably supposed to have one. The driver's side looks like it has one integrated into it. Would it hurt to run without? Just more risk of getting debris in the tube?

https://photobucket.com/share/ea819f14-5b35-43ce-9673-e2c98a4d0514

You need to take a small prybar and push the axle shaft OUT to compress the dust boot. Right now, the shafts are farther inboard than they run naturally, because the snap ring that holds them OUT is not installed.

Now before someone says: "But i run mind without a snap ring..." that doesn't matter.

When you install the hub and rotor and locking hub inner gear, it will pull the shaft out. (usually about 1/8 inch.) So don't condemn the long shaft until you know for sure.

Your passenger side shaft is obviously short. It will get shorter when you button up the hubs. I don't know if you care or not.

Your assessment of the axle shaft slinger is 100% correct.

 

[DirtDonk]

Regarding snap rings though, if you have aftermarket hub lockouts/locking hubs, you may not be able to get the snap rings back on.
It’s the same with many of the disc brake conversions. Sometimes they fit, sometimes they don’t.
With the Warn hubs, they almost never do.
Some axle shafts have two grooves for that purpose.

What do you run into with your builds James? Are you always using factory Spicer hubs? Or doing something else?

 

[jamesroney]

Regarding snap rings though, if you have aftermarket hub lockouts/locking hubs, you may not be able to get the snap rings back on.
It’s the same with many of the disc brake conversions. Sometimes they fit, sometimes they don’t.
With the Warn hubs, they almost never do.
Some axle shafts have two grooves for that purpose.

What do you run into with your builds James? Are you always using factory Spicer hubs? Or doing something else?

I use the factory Spicer hubs.

I used to run the Mile Marker Stainless hubs, with the cheap Chinese aluminum drive gears because they looked exactly the same as the ones that came out of the box that says “warn”

I’m convinced that the AVM Warn hubs are just as good as the Warn hubs that aren’t made in Sequim anymore. Or are they in Clackamas? Anyway the hubs in a box that says Warn that are not made in the Warn factory that doesn't make hubs anymore.

But my all time favorite today is of course the Dynalock hubs which are remarkably similar to the Yukon hubs. And since “Randy’s Worldwide” (dont call it “Randy’s Ring and Pinion” or they get mad…) anyway, Randy owns both now. So the Dynatrac boys are off to South Carolina, and Huntington Beach office will expire. Tailwind Capital seems to be the winner.

My point with the snap ring is only that at speed, while cornering, the u-joint will self-locate. So you need to have enough compliance to let the shaft find its natural center. The snap ring puts it there.