Dana44 questions

[4lo]

I just got a 79 chevy for cheep, it has a 10 bolt front with a broken ring gear and a 12 bolt rear. I want to get a 3/4 ton parts truck with a 44 front and a FF 14 bolt rear. I am fairly new to the whole 4x4 thing and wanted to know what year truck to look for. I know it will have to be between 74 and 78 but I have been told that there are alot of differences inbetween those years. I have three main questions.
1. Do some years have thicker axle tubes?
2. Is the 3/4 ton housing wider than a 1/2 ton?
3. Everyone is talking about flat top knuckles could someone tell me what this means?

[patooyee]

Originally posted by 4lo:
<STRONG>I just got a 79 chevy for cheep, it has a 10 bolt front with a broken ring gear and a 12 bolt rear. I want to get a 3/4 ton parts truck with a 44 front and a FF 14 bolt rear. I am fairly new to the whole 4x4 thing and wanted to know what year truck to look for. I know it will have to be between 74 and 78 but I have been told that there are alot of differences inbetween those years. I have three main questions.
1. Do some years have thicker axle tubes?
2. Is the 3/4 ton housing wider than a 1/2 ton?
3. Everyone is talking about flat top knuckles could someone tell me what this means?</STRONG>

I don't know about any years having different tube thicknesses, but the 3/4 ton housing is not any wider than a 1/2 ton. (At least in the front.) From what I hear, depending on years, they do differ, though. You can get anywhere from 67" to 69" on the half ton or the 3/4 ton. (67" being,by far, the most common. I think that the one tons were the main 69" ones, since my d60 front is 69")
Flat top knuckles are just what they say. The knuckles have machine-flattened surfaces on the tops. This makes them able to be drilled and tapped for cross over steering arms. All d44 Chevy fronts have flat driver's side knuckles, but only some had flat passenger side. I'm not sure of the years. My 1977 d44 front has flat tops on both sides.

J. J.


PS: I'm sure that if you do a search you will find loads of material on this subject.

[ 09-27-2001: Message edited by: patooyee ]

[scouter77]

http://home.earthlink.net/~smrnof100/highsteer/

Has pics of crossover/histeer conversion. Granted these are on a scout. They give an idea what it is compared to your steering. The passenger side has flattops (the only way to steer like this) and custom arms are put on the flattop with studs. Dont let years throw you off on parts. I had a 78 3/4 ton that didnt have a flattop knuckle on pass side. Know what you are looking for before you go. Also learn to tell the difference between 10bolts and d44's some dont and buy the wrong thing and get upset <IMG SRC="smilies/confused.gif" border="0"> not sur ehow but it happens. Also when buying try to get gears for it already. they aren't cheap so get what you want the first time. hope this helps.

[powermad]

This is what I just learned about the D44.
From 73-76 the tube OD is 2 3/4", 1/2 and 3/4 ton. In 77 it went to 3" 1/2 and 3/4 ton.
The 73-76 HD 3/4 ton axles had a tube thickness of 1/2". And they had the external hub. 77 on the 1/2 and 3/4 ton were the same except for the hubs rotors and backing plates.
I just got a 76 HD 3/4 ton D44 and have been
trying to find out as much as I can about it.

[Grim Reaper]

The Supposed "HD" is a farce. Yes it has strong tubes but it is not the tubes that fail it's the pumpkin. When they go the pumpkin will blow out where the tube is pressed in. And that takes some airborn action to cause.
Around 73 they did go up a size in U-Joints
You want a 8 lug D44 or 10 from 75 up to 91 as long as if has the internal style locking hub like the 1.2 ton. Don't get suckerd into that HD thing. Yeah the tube is thicker but your only gaining weight. If you need stronger then you need to be looking at a D60. All D44 after 73 and 10bolts are about the same strength. They have the same diam axle shafts.
The fact is DANA built the 10 bolt under contract from GM. all parts from the knuckle out are interchangable. You can run a 75 Spindle, Backing plate, hub on a 91 10 bolt no problem. It bolts right on. Just watch the Tierod. You need to run a matched set of knuckles so that you don't run into tierod mis matches.

[flexychevy1]

Originally posted by Grim Reaper:
<STRONG>The Supposed "HD" is a farce. Yes it has strong tubes but it is not the tubes that fail it's the pumpkin. When they go the pumpkin will blow out where the tube is pressed in. And that takes some airborn action to cause.
Around 73 they did go up a size in U-Joints
You want a 8 lug D44 or 10 from 75 up to 91 as long as if has the internal style locking hub like the 1.2 ton. Don't get suckerd into that HD thing. Yeah the tube is thicker but your only gaining weight. If you need stronger then you need to be looking at a D60. All D44 after 73 and 10bolts are about the same strength. They have the same diam axle shafts.
The fact is DANA built the 10 bolt under contract from GM. all parts from the knuckle out are interchangable. You can run a 75 Spindle, Backing plate, hub on a 91 10 bolt no problem. It bolts right on. Just watch the Tierod. You need to run a matched set of knuckles so that you don't run into tierod mis matches.</STRONG>

I will have to disagree with you on diameter of the axle shafts,being I had a late model 10 bolt and replaced with a late model 44.When I went to install the 44 I noticed it had a bad u-joint on the axle so I pulled the 10 bolt shaft out to see if I could use the joint and the 10 bolt was smaller including the shaft diameter.

[Grim Reaper]

Originally posted by flexychevy1:
<STRONG>I will have to disagree with you on diameter of the axle shafts,being I had a late model 10 bolt and replaced with a late model 44.When I went to install the 44 I noticed it had a bad u-joint on the axle so I pulled the 10 bolt shaft out to see if I could use the joint and the 10 bolt was smaller including the shaft diameter.</STRONG>

What year was the 10bolt? I have a 75 K5 with a D44 (well had, it now has a 81 10 bolt) and a 79 with a 10 bolt. The outer is identical. The inners were only different at the splines. The D44 had 27 as I recall and a different pitch. the 79 had 28. The 88-91's in the K5's and Burbs had 30. Pretty sure I got that right.
You sure that D44 didn't have aftermarket beefed shafts? Most beefed shafts are machined for full circle C-Clips for the u-joints and no taper just before the splines.

[The Rockslut]

The 44 has 30 spline axles 1.31" diameter the 10 bolt has 28 spline 1.29" diameter (not exact) They do share some common items like outers but the pinion diameter on the 10 bolt is bigger than the 44.

[Grim Reaper]

Originally posted by The Rockslut:
<STRONG>The 44 has 30 spline axles 1.31" diameter the 10 bolt has 28 spline 1.29" diameter (not exact) They do share some common items like outers but the pinion diameter on the 10 bolt is bigger than the 44.</STRONG>

Wasn't aware of the pinion size diffference. I do know that in the early 70's D44 ran a smaller u-joint and possibly even a smaller shaft. The change was around 73. Bud has a 72SB and kept snapping shafts and u-joint. I handed him a new u-joint for my 75 and it was too big. We got looking at the shafts noticed spline counts the same and he found 76 shafts and stopped breaking so many.

[The Rockslut]

The early 44's had 260X joints in the shafts and then went to the 297X that they currently still use. The 44 is stronger but the weak link is still the 297X not the carrier or R&P

[Shaker]

Originally posted by The Rockslut:
<STRONG>The early 44's had 260X joints in the shafts and then went to the 297X that they currently still use. The 44 is stronger but the weak link is still the 297X not the carrier or R&P</STRONG>

I 2'nd This.....But I would "truss" the bottom so it won't "snap" on the long side..... <IMG SRC="smilies/eek.gif" border="0"> <IMG SRC="smilies/eek.gif" border="0"> <IMG SRC="smilies/smokin.gif" border="0"> <IMG SRC="smilies/beer.gif" border="0">

[Hypoid Drive]

Originally posted by 4lo:
<STRONG>I just got a 79 chevy for cheep, it has a 10 bolt front with a broken ring gear and a 12 bolt rear. I want to get a 3/4 ton parts truck with a 44 front and a FF 14 bolt rear. I am fairly new to the whole 4x4 thing and wanted to know what year truck to look for. I know it will have to be between 74 and 78 but I have been told that there are alot of differences inbetween those years. I have three main questions.
1. Do some years have thicker axle tubes?
2. Is the 3/4 ton housing wider than a 1/2 ton?
3. Everyone is talking about flat top knuckles could someone tell me what this means?</STRONG>

1st the 3/4 ton housing has slightly thicker axle tubes than the 1/2 ton 2nd the 3/4 ton axles are 69 1/4 while the 1/2 tons are 67.5" 3rd as far as the flat top knuckles go there is no difference in the left front its the right front that is the one you need it has a flat suface on top suitable to milling and duplicating the driver <IMG SRC="smilies/biggrin.gif" border="0"> <IMG SRC="smilies/biggrin.gif" border="0">

[flexychevy1]

The 10 bolt was out of a 1980 and the 44 was out of a 76.