Dana 44 Axle and u-joint help

[BrianG]

I posted a similar post in the 67-72 pages, but realized this might be a better place for answers to this question.

After hours of searching, I can't seem to find an answer to a couple of questions.

I have two Dana44 Axle assemblies. I'm trying to make one. The one that is under the truck which I am rebuilding is a smaller tube (older I believe) unit. I just replaced the ball joints and am half way through with the axle u-joints. I needed some parts off the other housing that I have so I tore it apart. Upon doing so, I realized that the axle shafts are much thicker in diameter on the one that is not under the truck. I also realized that the one out of the truck has bigger axle tubes. I believe the one that is out of the truck is around 76 or 77 and the one under the truck is possibly a 72. I am planning on using the hubs and spindles from the newer unit. (more confusion here, because it seems as though there was a changeover of parts at this time and you could have one of two bearing sizes)

So, my first question is, can I, or should I use the heavier axles from the big tube Dana 44 in my small tube Dana 44 housing??? The lengths seem the same, the splines all match up, only the thickness seems different.

My second question pertains to the u-joints. I've read and read about differences in the u-joints, but I have installed one already and it seemed to go in with no issue, so I think I'm good there. Can anyone tell me if the u-joints are just really close and maybe it just seemed okay when I put the one in, or are they enough different that I would have been able to notice? Like I said, it seemed to go in just right, the internal snap rings lined up correctly and the joints seems to operate properly.

Any and all help would be greatly appreciated.

[BrianG]

Originally Posted by BrianG

I posted a similar post in the 67-72 pages, but realized this might be a better place for answers to this question.

After hours of searching, I can't seem to find an answer to a couple of questions.

I have two Dana44 Axle assemblies. I'm trying to make one. The one that is under the truck which I am rebuilding is a smaller tube (older I believe) unit. I just replaced the ball joints and am half way through with the axle u-joints. I needed some parts off the other housing that I have so I tore it apart. Upon doing so, I realized that the axle shafts are much thicker in diameter on the one that is not under the truck. I also realized that the one out of the truck has bigger axle tubes. I believe the one that is out of the truck is around 76 or 77 and the one under the truck is possibly a 72. I am planning on using the hubs and spindles from the newer unit. (more confusion here, because it seems as though there was a changeover of parts at this time and you could have one of two bearing sizes)

So, my first question is, can I, or should I use the heavier axles from the big tube Dana 44 in my small tube Dana 44 housing??? The lengths seem the same, the splines all match up, only the thickness seems different.

My second question pertains to the u-joints. I've read and read about differences in the u-joints, but I have installed one already and it seemed to go in with no issue, so I think I'm good there. Can anyone tell me if the u-joints are just really close and maybe it just seemed okay when I put the one in, or are they enough different that I would have been able to notice? Like I said, it seemed to go in just right, the internal snap rings lined up correctly and the joints seems to operate properly.

Any and all help would be greatly appreciated.

????No one????

[Redcap]

Originally Posted by BrianG

????No one????

Give it a day or two.

[JIMs70GMC]

The u-joints on the older one would be the -260 and the newer would be -297 which are larger so you would need to use axle/stubs together. As for the larger diameter in the earlier housing, if you use the newer knuckle/hub/spindle assembly it should work. (there is a seal in the housing near the "hogs head" that keeps the gear oil in, that might need to be replaced if the axle does not "neck down" for the seal.)

[ryanroo]

Originally Posted by BrianG

????No one????

Most folks are at work during the day, so response time is a little slower.

The stock axles from the early 70s, and i am not sure when this change over happened, had 260x u joints and necked down. the bigger ones happened at some point, i want to say mid 70s. they are 297x u-joints and non neck down. you can use them interchangeably. i would use the bigger ones for the sake of manliness, but if you are using the truck more as a driver and not as a wheeler, the smaller joints will probably serve you flawlessly.

the change in the size of the wheel bearings happened in the same time frame i believe. if you want to use the larger bearing hub, you need to use the spindle and hub from the axle that it comes from. it will interchange with the smaller hub/spindle set up as well.

i am mildly curious about the difference in axle tubes. as far as i knew, the OD was consistent. the wall thickness changed between 3/4 and 1/2 ton but as we are speaking of the differences in wheel bearing assemblies i will assume we are working on 1/2 ton(6lug) axles.

[BrianG]

Originally Posted by ryanroo

Most folks are at work during the day, so response time is a little slower.

The stock axles from the early 70s, and i am not sure when this change over happened, had 260x u joints and necked down. the bigger ones happened at some point, i want to say mid 70s. they are 297x u-joints and non neck down. you can use them interchangeably. i would use the bigger ones for the sake of manliness, but if you are using the truck more as a driver and not as a wheeler, the smaller joints will probably serve you flawlessly.

the change in the size of the wheel bearings happened in the same time frame i believe. if you want to use the larger bearing hub, you need to use the spindle and hub from the axle that it comes from. it will interchange with the smaller hub/spindle set up as well.

i am mildly curious about the difference in axle tubes. as far as i knew, the OD was consistent. the wall thickness changed between 3/4 and 1/2 ton but as we are speaking of the differences in wheel bearing assemblies i will assume we are working on 1/2 ton(6lug) axles.

I'll get some pics soon and show you the difference. I was also surprised at the tube differences. Both are half ton. I took the bill of material numbers off of both, but I can't find any reference to the earlier (smaller) housing to confirm its year.

[argonaut]

I'm curious also. Awaiting the photos!

[BrianG]

Well, photos were hard to get which showed the differences in tube diameter. From what I can tell, the one under the truck is around 2.75" while the other that I have that I'm using parts from is around 3". I did discover that the 2.75" tube housing actually has thicker tube walls. I've read in a few places that this is considered slightly stronger, but I'm sure many will debate that, and that's not what I'm trying to get started.

I took pics of the bill of materials from both. I can't find any reference to the one under the truck. This is the first picture. with approx. 2.75" tubes

The next picture is of housing outside of truck... This looks up to be a 76 housing.


I found a u-bolt that was a bit larger than either housing, you can see how I can't get a large screwdriver between the u-bolt and the housing on the bigger housing, but it fits with extra room on the smaller housing.



Here is a post I found while searching that explains some of the size differences.

[BrianG]

Here is a couple of pics of the differences in wall thickness.

I used the screwdriver to try to show the differences in wall thickness.

Its hard to see, but on the smaller tube with thicker wall, (older housing under truck) the width of the tip of the screwdriver goes up to where the taper starts. On the housing with the bigger tube with thinner wall, the screwdriver tip width is equal to the whole tube wall including the chamfer.

Post #7 on this old thread

http://67-72chevytrucks.com/vboard/s...d.php?t=162442

says that the smaller tube has a .5" wall while the larger tube has a .375" wall. I'm not a mechanical engineer, and although .5 is bigger than .375, I know that overall diameter means a lot in regards to strength. Those really REALLY using both might be able to weigh in on which is truly stronger.

[BrianG]

I am still a bit confused by one thing. The axles under my truck were the necked down smaller diameter axle shafts. The one that I'm putting back in are from the larger diameter housing and are the larger diameter axle shafts. I've read in many places that the u-joints are different, but I can not see any difference in them. I don't have pics handy of them but I told the parts guy I wanted u-joints for a 72 and they fit perfectly into the 76 shafts. Maybe this is a case of crossover. I do believe that the u-joints in the smaller shafts have been changed so maybe they were changed out to the larger joints. The u-joints in the larger axle shafts were original.