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Another, but differnet spline question

Emmettology 101

Emmettology 101

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Ok, on front axles, the 10 bolt has 28 spline shafts and what spline is the 44, 30?

I have seen and heard people say that the 10 bolt shafts and 44 shafts were not interchangable and I believe it was due to spline count.

Here is my question or situation.

My Jimmy had a 10 bolt when I bought it and I had a 8-lug 44, from a 3/4 Chevy, sitting there that I swapped in due to the 4.10 gears and I swapped the 44 over to 6-lug. Well at the time I didn't think or know there was a differnce and I used the 10 bolt shafts because they looked better. I have bee using them for 2 years with no problems.
My brother just recently bought a Blazer and used a 10 bolt in the front with the 44 shafts with no problems.

Both sets swapped into the other housing with no problems.

Why do people say this wont work or that they are different?
I know the carrier is different in the 44 and uses larger bearings, but what about the shafts?

Mike
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1982 GMC Jimmy - <font color=green>Emmett</font color=green>
http://emmett.coloradok5.com
 
I know the 10 bolt only had 28 plines but you could put a rear carrier in the front to make it 30 spline.

But I dont know about the D44. I have also seen a lot of people out there saying they have a HD 44 which has bigger steering u-joints. I thought I had the largest 44(3/4 8-lug with the large hubs)but mine uses the same steering u-joints as the 10 bolt.
I may have to give Stephan a call.

Mike
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1982 GMC Jimmy - <font color=green>Emmett</font color=green>
http://emmett.coloradok5.com
 
As far as I know, all Dana 44 fronts used in GM vehicles (and all others for that matter) had 30 spline shafts, I have never heard of a 28 spline Dana 44 (though it may exist). The so-called "heavy duty" Dana 44's, in my opinion, are just considered h.d. because of the 8-lugs and that they were used in 3/4 ton trucks. Some earlier 44's (late '60s, early 70's) had the smaller 260-x steering u-joint (just like a Dana 30 front axle), while all of the later models had the larger 297-x joint. I'm pretty sure that since the early '70s all 44's used the larger joint, whether it was 1/2 or 3/4 ton, 6 lug or 8 lug.

Most 10-bolt fronts were 28 spline. There were 30-spline front 10 bolts offered from the factory, but only in the '90-'91 Blazers and Suburbans, which makes them very rare and hard to find (trust me, I've been trying to find some stock replacements for my '90 for a year). Most drivetrain shops either did not know they existed, or thought they were the same as the Dana 44's.......even Stephen Watson at ORD didn't know they existed until I called about their chromoly axles. I also tried buying 30 spline 10-bolt axles from Randy's Ring and Pinion (had always been very good in the past about parts)......they sent me Dana 44 INNER shafts and they are NOT THE SAME, the outer stub shafts are the same.

The differences between the 30 spline 10-bolt and the 44 are as follows:

1. the inner shafts are a different length by about an 1/2", this is due to the 10-bolt diff being more centered than the 44 (10-bolt is 1/2" longer on the short (right) side and 1/2" shorter on the long (left) side). This also means you will probably only have about half as much contact between the axle splines and the splines in the carrier.

2. the seal surfaces are in different areas

3. the spline pressure angle (the angle the splines are cut at) are different between the two, though supposedly this doesn't hurt anything in a front end application that really won't get that many miles on it.

I will try to attach a picture I have if it isn't too large.

Stephen at ORD should be able to re-confirm the above.

Also, if somebody put 28 spline 10-bolt axles in a Dana 44, I would highly recommend pulling them out and double checking the situation. I guess there is a chance that the 28 spline shafts would fit in the 30 spline carrier, since the 28 spline shafts are slightly smaller in diameter than the 30 spline ones, and be catching enough splines to power the front tires....but it can't be good.
 
I have had them out and check the splines and they were fine, but I will have to check for where area indicated in you pic where is looks like a bearing rides.

Mike
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1982 GMC Jimmy - <font color=green>Emmett</font color=green>
http://emmett.coloradok5.com
 
I know that you can put a 28 spline axle shaft in a 30 spline 10 bolt rear, since I have done it. The shaft will slide right in, but the splines do not catch at all, it just turns free in the hole. This happened to me when I bought a new shaft for the 10 bolt rear end in my '87 Suburban. It should be a 28 spline axle, but apparently the whole axle was replaced at some time in the past, because it is a 30 spline carrier now.

Tim

1970 Blazer CST 4X4 350 SM465 NP205
1987 Suburban 4X4 350
1988 Chevy Pickup 4X4 350
 
I cna spin the front no problem, thy lock in good and the splines dont slip.

I was even in the rock fest in Canfield a couple weeks ago and made it almost just as far a s my brother who has lockers. But I have more off-road driving experience under my belt.

Mike
tongue.gif

1982 GMC Jimmy - <font color=green>Emmett</font color=green>
http://emmett.coloradok5.com
 
I'm not the expert here, but my previous dana 44 has 28 spline shafts. That was in a 77, but who knows what year it really was. Lock-rite also makes a locker for that carrier.

The differences between and "HD" 44 and regular, to my knowledge, is the size of the wheelbearings and lockouts. Spindles, u-joints, gears, etc are all the same.

Squash
http://www.trailrunners4x4.org/users/realsquash
 
Hey 6.2Blazer, EXCELLENT description!!! I couldn't a said it better myself!! Also, THERE WERE NEVER EVER ANY 28 SPLINE DANA 44s. EVER! If you think you have a 28 spline 44, look at the diff cover, you got a GM 10 bolt, which were available as early as 1977. And, spindles are most definitely different on 44s, with the change coming in mid-year '76.

ken
 
I looked up a couple of application guides for the Lock-Rite and only found listings for a 30-spline Dana 44, no 28 spline 44's mentioned.
Emmetology - are you sure you switched axleshafts between a Dana 44 and a 10-bolt? I suppose there is a chance a 30 spline 10-bolt had been swapped into your Blazer, but other than that I really don't think there is any way to interchange shafts and not have some obvious problems.
 
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