Converting F-150 HP D44 to 8 lugs

[Scott Cee aka 2drx4]

I'm back and forth on it but I think I'd rather run 8 lug on my 77 F-150 HP D44.

I don't have access to a F-250 D44, at least not that I'm aware of. These parts are getting harder to find it seems and it was something of a miracle I found a good F-150 axle to start with. I have lots of random D44 parts around, but nothing that seems like it works for 8 lug stuff, short of tearing the front out of my 76 K25 and stealing the knuckles out off it (not going to do that).

Raybestos sells the 8 lug hub and rotor for the F-250:

https://www.rockauto.com/en/moreinfo.php?pk=1075322&cc=1123085&jsn=2397
https://www.rockauto.com/en/moreinfo.php?pk=391082&cc=1123085&jsn=2264

Yukon sells what I believe is the right spindle:

https://www.yukongear.com/productdet...px?ProdID=6064

That said, Yukon's listing of the spindles is ambiguous, and the three options are here: https://www.yukongear.com/partslist....tName=Spindles

The other spindle they list as being for F-150 and F-250s with the "reverse rotation" D44 doesn't seem to be the right one just crossing the bearing sizes through Rockauto, but I could be wrong.

Obviously the hub offset is a little different between the F-150 and the F-250, and the spindles and bearings are definitely different. Also the rotor is thicker, but has a deeper hat. I don't really have dimensions listed anywhere to know how different things wind up lining up if you do this, Raybestos is nice about publishing rotor dimensions but not the hubs. The Yukon spindle is also longer, which implies probably a different outer axleshaft (I have not checked).

Would I need to track down the F-250 caliper mount bracket then? Rockauto lists the same single piston caliper as fitting both the F-150 and the F-250 4wd (or at least it does not call them a RWD caliper), however they also list a dual piston caliper for the F-250 "4wd crewcab" model which uses an obviously different mounting style. Example of the dual piston caliper: https://www.rockauto.com/en/moreinfo.php?pk=311993&cc=1123085&jsn=2414 Is that the actual correct caliper for the 8 lug F-250?

If I can hodge podge this crap together how much will it affect track width? Looks like I'd gain an inch each side.

 

[Scott Cee aka 2drx4]

I guess what I'm forgetting (assuming I'm right about it) is that the 8 lug HP D44 was not used in the crew cab F-250. So therefore the LP version used in the crew cab probably takes the dual piston calipers and the HP version does not, and possibly the HP version is also the HD/upgross version of the axle. That would also explain a possible difference in the spindle. However, that then leads to the question of if that Raybestos 8 lug hub is the correct one for that spindle or not (or which spindle is the correct one).

Also I guess the question should be is the Raybestos hub a quality enough product to even bother with?

 

[reptillikus]

8 lug HP D44 was def used in late 70s F250s. I thought it was an 8-lug spindle though, so you needed everything from the knuckle out. It used D44 sized wheel bearings, and the big dual piston caliper just like the D60.

 

[Hyde]

I have the hp44 out of my 79 F250 laying out back somewhere, I can tell you what calipers are on it if that will help

 

['84 Bronco II]

The spindles and outer axle shafts are longer for the 8 lug Dana 44. They are also the dual piston calipers with the caliper bracket being a cast piece sandwiched between the spindle and the knuckle. I just bough wheel bearings for mine a little while ago, and they are definitely smaller than Dana 60 wheel bearings, so I wouldn't be surprised if they are the same wheel bearings as what are used for the 5 lug stuff.

Also, the 8 lug spindles have a 5 stud bolt pattern, not 8.

 

[Scott Cee aka 2drx4]

8 lug HP D44 was def used in late 70s F250s. I thought it was an 8-lug spindle though, so you needed everything from the knuckle out. It used D44 sized wheel bearings, and the big dual piston caliper just like the D60.

I wasn't contesting that it was used at all, it's just I believe the crew cab got the LP version like they did with the D60s in the F-350. I could be wrong though.

Which spindle is it then? It won't be an 8 stud one, none such thing exists, when I was saying a 5 stud spindle I mean how it attaches to the knuckle.

2.0" and 1.625" bearing journals:
https://www.yukongear.com/productdet...px?ProdID=6064

2.05" and 1.64" bearing journals:
https://www.yukongear.com/productdet...px?ProdID=6203

Obviously they had multiple GVW axle ratings.

This is the F-150 one almost for sure for comparison, 1.78" and 1.625" bearing journals:
https://www.yukongear.com/productdet...px?ProdID=6304

I have the hp44 out of my 79 F250 laying out back somewhere, I can tell you what calipers are on it if that will help

Snap a picture if you can, just to clear it up for me. Although I'm guessing it will be the dual piston as reptillikus said.

 

[Scott Cee aka 2drx4]

The spindles and outer axle shafts are longer for the 8 lug Dana 44. They are also the dual piston calipers with the caliper bracket being a cast piece sandwiched between the spindle and the knuckle. I just bough wheel bearings for mine a little while ago, and they are definitely smaller than Dana 60 wheel bearings, so I wouldn't be surprised if they are the same wheel bearings as what are used for the 5 lug stuff.

Also, the 8 lug spindles have a 5 stud bolt pattern, not 8.

Okay, so which spindle is it, and are all the 8 lug spindles (I mean that is to accept an 8 lug hub, I know they take 5 studs) and hubs all the same?

The F-150 version also uses the sandwiched caliper mount. I take it it is a different caliper, but Rockauto's listings are ambiguous without seeing how it was supposed to be assembled.

 

['84 Bronco II]

I wasn't contesting that it was used at all, it's just I believe the crew cab got the LP version like they did with the D60s in the F-350. I could be wrong though.

Which spindle is it then? It won't be an 8 stud one, none such thing exists, when I was saying a 5 stud spindle I mean how it attaches to the knuckle.

2.0" and 1.625" bearing journals:
https://www.yukongear.com/productdet...px?ProdID=6064

2.05" and 1.64" bearing journals:
https://www.yukongear.com/productdet...px?ProdID=6203

Obviously they had multiple GVW axle ratings.

This is the F-150 one almost for sure for comparison, 1.78" and 1.625" bearing journals:
https://www.yukongear.com/productdet...px?ProdID=6304



Snap a picture if you can, just to clear it up for me. Although I'm guessing it will be the dual piston as reptillikus said.

It is this one: https://www.rockauto.com/en/moreinfo...=1123300&jsn=9

I guess that would be your second Yukon one, but I am not sure why they are claiming the funky bearing sizes.

EDIT: Looks like a typo on Yukon's website. Denny's Driveshafts specifies the normal 2" and 1.625" bearings for that part number. Also, I guess I lied about the spindle being longer, it seems only the earlier closed knuckle axles used the longer spindle. I am guessing that means the outer axle shafts are the same too, so all you should need to do is convert the brakes to get the 8 lug outers.

 

[Scott Cee aka 2drx4]

The one I highlighted in red.

Any idea what the even bigger one is for then? Seems like a weird option.

 

['84 Bronco II]

Any idea what the even bigger one is for then? Seems like a weird option.

Sorry, see my post I edited, I messed up.

 

[Scott Cee aka 2drx4]

It is this one: https://www.rockauto.com/en/moreinfo...=1123300&jsn=9

I guess that would be your second Yukon one, but I am not sure why they are claiming the funky bearing sizes.

EDIT: Looks like a typo on Yukon's website. Denny's Driveshafts specifies the normal 2" and 1.625" bearings for that part number. Also, I guess I lied about the spindle being longer, it seems only the earlier closed knuckle axles used the longer spindle. I am guessing that means the outer axle shafts are the same too, so all you should need to do is convert the brakes to get the 8 lug outers.

Okay. So I'd need:

-Yukon SP700004 spindles
-Raybestos 4294R hubs
-Wheel bearings (I can figure the P/Ns out)
-F-250 caliper bracket (does anyone sell these?)
-Raybestos RC7003/70004 calipers (dual piston types)



Any comments on the increase in track width? Eyeballing the parts says it must. F-150 hub https://www.rockauto.com/en/moreinfo.php?pk=1075444&cc=1120802&jsn=2393&jsn=2393

versus F-250 hub https://www.rockauto.com/en/moreinfo.php?pk=1075322&cc=1123085&jsn=2397

 

['84 Bronco II]

Okay. So I'd need:

-Yukon SP700004 spindles
-Raybestos 4294R hubs
-Wheel bearings (I can figure the P/Ns out)
-F-250 caliper bracket (does anyone sell these?)
-Raybestos RC7003/70004 calipers (dual piston types)



Any comments on the increase in track width? Eyeballing the parts says it must. F-150 hub https://www.rockauto.com/en/moreinfo...=2393&jsn=2393

versus F-250 hub https://www.rockauto.com/en/moreinfo...23085&jsn=2397

I think the spindle is the same as the spindle currently on your truck, so no need to buy new ones. I don't think anyone is manufacturing new caliper brackets, so that may throw a wrench into things. There may be an issue though using the F150 knuckles with the F250 caliper bracket anyway even if you do manage to find one according to this post: https://www.ford-trucks.com/forums/1...ml#post9679163

In order to make use of the larger brake rotors and calipers, you need to change from the knuckle out. This is becasue the 150 knuckle and caliper bracket are machined to clear the smaller caliper. The 44hd knuckle has a relief cast in to clear the different bracket. You can physically mount the 8 lug hub/rotor setup on a regular d44 spindle, but you will need to make your own brake caliper bracket and an aftermarket caliper as the factory ones won't work right.

Maybe you can grind the F150 knuckle and/or F250 caliper bracket?

 

[Scott Cee aka 2drx4]

I think the spindle is the same as the spindle currently on your truck, so no need to buy new ones. I don't think anyone is manufacturing new caliper brackets, so that may throw a wrench into things. There may be an issue though using the F150 knuckles with the F250 caliper bracket anyway even if you do manage to find one according to this post: https://www.ford-trucks.com/forums/1...ml#post9679163



Maybe you can grind the F150 knuckle and/or F250 caliper bracket?

Gotcha, I suppose I could get off my lazy ass and measure the spindles I have and confirm. The axle is apart.

Beyond that I guess I could just buy a hub/rotor/bearings and see how things line up with my caliper brackets.



The other option is to bastardize it with newer GM parts. Since it looks like I can just go GM knuckles out and it will all work well enough, and there's more GM stuff around still.

 

[Hyde]

79 8 lug HP44

 

[Scott Cee aka 2drx4]

So my spindle will definitely not work with the 8 lug hubs. It is the spindle that I thought it would be.

Hyde, thanks for the pics. Definitely a totally different caliper mount from mine.

 

[Hyde]

Just to clarify the two large bolts aren't the calipers mounts or slides, it has a knock out with a leaf spring on the bottom like a lot of calipers of the era. Not sure if you know but thought it's worth mentioning

 

['84 Bronco II]

I appreciate you posting up some pictures of actual tech instead of just conjecture. It will be nice if you take pictures and document everything here to clear up a lot of the contradictory info out there, assuming you don't just take the easy way out and swap everything from the knuckle out off an 8 lug axle.

 

[Scott Cee aka 2drx4]

I appreciate you posting up some pictures of actual tech instead of just conjecture. It will be nice if you take pictures and document everything here to clear up a lot of the contradictory info out there, assuming you don't just take the easy way out and swap everything from the knuckle out off an 8 lug axle.

Unfortunately I think I'll have to go the GM route. I have a line on a complete GM D44 for less than the spindles from Yukon would be.

I'm going to throw out a feeler for some 8 lug Ford stuff though, and if anything pops up before I commit to the GM I will go that way. Then I can at least take it apart and measure things to be more certain of what would or wouldn't work.

 

[reptillikus]

The axle that hyde posted pics of, is the same one i used to have. Came out of a '78 F250.

I am guessing that means the outer axle shafts are the same too, so all you should need to do is convert the brakes to get the 8 lug outers.

As i recall, in the late 70s Fords all leaf sprung D44s used different inners than the coil sprung D44s, but the stubs were the same in all of them. It was the 3/4 ton chevy d44s that had a longer stub, so you had to use the chevy spindle, hub & stub when you converted to 8 lug (this is how i did my D44 TTB actually).

Which spindle is it then? It won't be an 8 stud one, none such thing exists, when I was saying a 5 stud spindle I mean how it attaches to the knuckle.

I had to go back and check. Dana Spicer p/n# 707043X. Scouts used it. Id have sworn it was a Ford spindle but i guess not.
https://www.drivetrainamerica.com/70...8-hole-flange/



Mr.N's D44 page is technically still viewable online, if you use the Wayback Machine:
https://web.archive.org/web/20060520.../web_rs44.html

There is a TON of D44 info on there.

There may be an issue though using the F150 knuckles with the F250 caliper bracket anyway even if you do manage to find one according to this post: https://www.ford-trucks.com/forums/1...ml#post9679163



Maybe you can grind the F150 knuckle and/or F250 caliper bracket?

You can see the difference in the knuckles on Mr. N's page, under the section on Flat-Top Knuckles. Looks like if you want to swap to the dual piston caliper & mount, you have to use the F250 knuckle, in order to clear the caliper mount. So if you can find a complete 8-lug D44 for parts id go that route. Otherwise it might be easier to go the chevy route, esp if you already have access to one. The JB6 calipers are bigger than half ton Ford, and the JB7 calipers are bigger than one ton Ford. Both are single piston. Technically theyre not interchangeable but they have the same pin spacing so it should be possible to grind the mount to fit the larger caliper, should you choose to do so.

A lot of people used to swap to a Tbird caliper onto their half ton D44s as its a mostly direct swap and its a ton bigger than stock, but i dont know if it fits over the bigger 3/4 ton rotor.

 

[Scott Cee aka 2drx4]

I'm just going to upload these pics before I digest the current comments.

This is the style of caliper bracket I have. It uses the same spring clip setup as the F-250. As I said I have not digested the comments to know if that means it can take the F-250 caliper.

Bracket P/N is 3204157-L and -R (I assume, didn't actually look at the other one )

This is the knuckle I have. Large clearanced area for the calipers. I recall arguments "back in the day" that these were weaker than the GM/FSJ knuckles because of the clearancing.

Another random comment is god damn is the spindle "pilot" hole in the knuckle big compared with the GM/FSJ knuckle and spindles I have. That would be way more convenient, I recall having to absolutely get medieval to got an axleshaft through a FSJ one after the ears opened up from some abuse.

 

[Scott Cee aka 2drx4]

Gm stuff is probably the right move for you seeing as you already have that k20. Having brakes, calipers, and spindles interchange means you only need one set of spare parts sitting on the shelf.

Its nice to finally see the real you over here. You can change your name, but you’ll always be the filthy injun to me

​

The K truck I have uses the earlier setup with the external (bolt on) hubs and whatever. I keep saying if I break one more fucking thing in that axle I'll put a D60 in it instead, but apparently that hasn't happened.

And get fucked.

 

[Scott Cee aka 2drx4]

The axle that hyde posted pics of, is the same one i used to have. Came out of a '78 F250.



As i recall, in the late 70s Fords all leaf sprung D44s used different inners than the coil sprung D44s, but the stubs were the same in all of them. It was the 3/4 ton chevy d44s that had a longer stub, so you had to use the chevy spindle, hub & stub when you converted to 8 lug (this is how i did my D44 TTB actually).




I had to go back and check. Dana Spicer p/n# 707043X. Scouts used it. Id have sworn it was a Ford spindle but i guess not.
https://www.drivetrainamerica.com/70...8-hole-flange/



Mr.N's D44 page is technically still viewable online, if you use the Wayback Machine:
https://web.archive.org/web/20060520.../web_rs44.html

There is a TON of D44 info on there.





You can see the difference in the knuckles on Mr. N's page, under the section on Flat-Top Knuckles. Looks like if you want to swap to the dual piston caliper & mount, you have to use the F250 knuckle, in order to clear the caliper mount. So if you can find a complete 8-lug D44 for parts id go that route. Otherwise it might be easier to go the chevy route, esp if you already have access to one. The JB6 calipers are bigger than half ton Ford, and the JB7 calipers are bigger than one ton Ford. Both are single piston. Technically theyre not interchangeable but they have the same pin spacing so it should be possible to grind the mount to fit the larger caliper, should you choose to do so.

A lot of people used to swap to a Tbird caliper onto their half ton D44s as its a mostly direct swap and its a ton bigger than stock, but i dont know if it fits over the bigger 3/4 ton rotor.

Random comments.

I think the leaf sprung axles were wider, hence the different inners. This axle is bang on the width I want, but I didn't select it because of that, rather because it was the only HP D44 with normal tubes that the junkyard had. I would have been more than willing to cut down a wider one if needed. And if some sort of hub conversion malarky makes this thing too wide I would consider cutting it down too, but only after I run the numbers on scrub.

(Edit, maybe they took shorter inners so they came out to a similar width with the "wider" hubs on them? I guess I could look at some axle shaft lengths and figure that out.)

The spindle you linked is an TTB (Twin Traction Bullshit I believe) spindle. Is that the one you intended to link? Those spindles and hubs are still readily available in the junkyards.

Looking at Mr N's page confirms the worst. The knuckles I have are the weak F-150 ones (well, that makes sense, the axle is out of a F-150). I'm not sure how I feel about that, I'm building a truck with 33"~ tires, so it probably isn't an issue. That said, I'd rather not leave a known weakness. I think the F-250 calipers and mount will clear the F-150 knuckle, if I am seeing that correctly, as I think they spaced the rotor and caliper farther outwards to avoid needing the massive clearanced area that the F-150 knuckle has.

(Edit again, even just going to the dual piston caliper would improve the clearance issues given if they're using the same mounting spread, the two pistons would mean it would have to cut into the knuckle less)

I will have to think about this more.

 

[Scott Cee aka 2drx4]

In the spirit of trying to add some tech to this... well I went and snagged some GM 8 lug stuff because cheap.

Hub height difference. .650~ because I'd really need to clean them and put them on the proper table to say for sure. This is also assuming the spindle and knuckle locates them in the same place, I will measure that later.

However the rotor goes on the back of the GM hub and the front of the Ford. So that's about .325" less for the difference. So really I'm going to gain only about 5/8" more track width assuming the knuckles and spindles locate the same, as I said before.

Hub meat is totally different. The GM hub clearly is a lot more girthy. I guess that's how those GM guys like it.

 

[Scott Cee aka 2drx4]

From there I figured I'd check if the spindle mating face on the knuckle is on the same place GM versus Ford. Mr N said they should be, but you can never trust anything.

GM is 4.5"

Ford is 4.5" (pardon my lack of three hands to hold a straightedge at the same time)

From there the question was if the spindle face versus the back of the spindle is the same, and this picture shows it reasonably well. Keep in mind the Ford spindle has the caliper mount bracket between it and the knuckle, so I put that in there. Also I goofed a bit on the picture and took it from an angle with the GM spindle a bit in front of it, but you get the point, they're basically the same if not exactly the same. This isn't a precision ground table after all.

From there I could put the hub on the spindle and measure the difference. Now I get .625", which again would be minus the .325" for the rotor. So as I'd assumed before, it should be about a 5/8" increase in track width as a maximum.