12-Bolt Front Axle?

[John Galt]

So I thought I bought a front 8-Lug Dana 44, but I pulled it apart and it was bigger than the 44, ring gear was larger as was the carrier, and outer axle shafts longer. the carrier had 12-bolt stamped on it. any ideas as to what this is? i went to a junkyard to find a 44, but they all look the same as the so-called 12-bolt I already have. Does anyone know what this is?
What years did Dana 44 8-Lugs come on Chevys?

I already have a D44 detriot and gears, so that's why I am looking for a D44.

[Grim Reaper]

No such thing. Count the bolts that hold the diff cover to the pumpkin. That's the bolts that give it a 10 bolt or 12 bolt designation. A D44 also has 10 bolts holding the cover on. Don't remember if a D60 has 12 or not. The covers have a different shape. a 10 bolt front has more of a round cover where as the D44 is squared off on the sides. I think if you count there will be 12 bolts that hold the ring gear to the carrier. They may have cast that into the carrier so that they could quickly identify how many holes needed to be drilled into the carrier for the ring gear it was to recieve.
Now the D44 front in a 3/4 ton stopped 77-78. After that it went to a Corp 10 bolt through the end of production in 87 (may have run till 91. Not sure if the 3/4 tons changed with the 87 or if they ran through 91 like the 1 tons and crews did). The other possiblility is you got a D60 and if you got a D60 for the Price of a D44 then you got a deal! As for the shaft lenghts....I know that everything from the knuckle out is interchagable between the D44 and the 10 bolt. DANA Built the 10 bolt under contract from GM. The inner axles have a different spline count but should be the same lenght. I would think a D60 would be the only other axle that there might be a different lenght shaft that would be a simular size. Do the steering knuckles have a square plate with a nipple on top and 4 bolts holding it down.
If you do have a D60 by accident You might be able to talk me into getting you a D44 if that's what you have to have and swap you even.

A FRONT 12 Bolt is a mytical creature like a Unicorn that nobody else in the world has seen. If you still feel it's a 12 bolt get some pictures up where we can see it and get a picture of where you say it has 12 bolt cast. I have 4 GM vehicles with 12bolt rears and I have never seen "12 bolt" cast into them.

[ 09-05-2001: Message edited by: Grim Reaper ]

[John Galt]

Thanks for all the info!!

Actually, it just says "GM 12" cast into it.
The more I think about it, the more I think it is a 10-bolt. I will check the bolts tonight. I was just comparing the lengths of the outer axle shafts from my Scout D44 to the "10-bolt", that's all. the scout inner shafts fit into the 10-bolt carrier, as far as splines are concerned. it does have a circular shape to it, not like my Scout D44 that is all angled.

aren't 60 shafts bigger than a 44? same with the axle tube? it doesn't have the 4 bolts on top of the knuckle.

So is a 10-bolt stronger than a 44 since the carrier and everything is bigger?

[Lloyd]

Go here http://www.coloradok5.com/axleguide.shtml and see what the cover looks like first. A 10-bolt front is marginally weaker than a 44 if the 10-bolt has the usual 28-spline axles; but chances are if you're gonna break one you'd break either. Other internal parts are pretty similar in size and strength but won't interchange - knuckles out are the same. I've never heard of a 12-bolt front either. If you've really got a 60 and want a 44 I'll drive my spare axle out to you for a swap right now - I'll even bring you TWO complete d44 fronts. If it really is a 12-bolt I might trade just to have something that no one believes exists.

[ 09-05-2001: Message edited by: Lloyd ]

[reddwarf]

John, the 10 bolt will have 10 bolts in the cover. The Dana axles, including the 60 also have 10 bolts.

You say the ring gear is bigger than the Dana 44. The ring gears in the Dana 44 and the 10 bolt are the same, @ 8.5"
The carriers are similar as well.

You say the case is angular rather than rounded. The 10 bolt has a rounded case with two very pronoounced ears cast on the bottom.

This is all very odd indeed.
Pic's would be worth, well, about 1,000 words each <IMG SRC="smilies/biggrin.gif" border="0">

[reddwarf]

Okay, I just read in Gen'l that you said it has 10 bolts, but I'm confused. The Dana 44 and the 10 bolt have the same size ring gear, yet you said earlier that the ring was bigger than on the Dana. What gives? Would you measure the ring gear diameter? See is it about 9.75" across...

[John Galt]

I counted the cover bolts last night, there are ten.
I will try to measure tonight the size of the ring gear, but I was pretty positive 2 Fridays ago at 3:00 in the morning that the Scout D44 stuff was a lot smaller.

I will also get the stamped number of the carrier and housing and maybe call GM and see if they can tell me what it is.

Most likey, just a 10 bolt and I've learned a humbling lesson.

[Dieselboy]

My old 10 bolt said, "GM12," on the bottom. As much as the axle tried to pretend it was a 12 bolt, it still was a 10. Don't let them fool you!

I wonder what the casting, "GM 6.2L," on my engine block means?

[Grim Reaper]

Ahhhh I see your problem. A Scout 44 and a GM 44 are not the same animal. Scout 44 is not as wide. Dana builds lots of axles that are taged "D44". They end up in lot's of vehicles in cluding Jeep, Rodeo, Trooper, GM, Ford (reverse cut at that). What I don't know is if they all run the same size ring and pinion. I think they do and close to the same pumpkin. However there are "carrier Breaks". So that they don't have to make 4 inch thick ring gears they change the offset of where the ring gear bolts to the carrier. The lower the gear (higher the number) the smaller the diameter of the pinion so the ring gear has to move towards the center. You may not be able to run that locker you have with the current gears that are in the axle.
A D44 carrier will not work in a 10 bolt housing. A d44 shims under the the carrier bearings and a 10 bolt shims outside the bearings. I also think the size bearings are different so they won't fit properly into the housing.
A 10 bolt and a d44 also have a differnt angle on the splines that go into the side gears and are not interchangable. Strenght of the shaft is about the same and both usualy fail at the taper next to where the inner axle shaft seal rides. Strenght is about dead even unless you luck up on a HD D44 that ran thicker tubes. The tubes rarely bend. Most of the time both axles will have the short side tube break the diff housing.

[John Galt]

This makes sense, and I noticed the difference in the way the 2 were shimmed once I had them both out, and that was my first clue that my little swap wasn't going to work.
Thanks for all the information!

[pcorssmit]

If you need a Chevy 44, I think my brother has one he'd let go pretty cheap. If you're interested, email me at pcorssmit@hotmail.com.

Pete

[John Galt]

I emailed you, am interested!

Thanks!