I'm trying to order rear U-Joint's since I have to reseal the transmission and t-case, but the delco web site lists half a dozen different joints.
How can I tell if I have an aluminum or steel drive shaft? It's a 95 SLT AN 5 body with 46RH transmission and 231HD t-case.
One site shows it taking a 1.20" and another 1.08", and another says it takes this part for an aluminum shaft, and yet another says it takes this part for a steel shaft.
ACDelco just says position 1,2,3,5,6 blah blah. It's driving me insane.
Anyone know wth this friggin thing uses? I should have listened to my gf's father.."Buy a Ford", he said, "You'll be sorry".

edit:
I guess it's a steel shaft since a magnet sticks to it and has a hallow echo when flicked, but there's not a spot of rust anywhere.

 

Yup grab a magnet, even a refrigerator magnet will work. As for the size the quickest way is grab some calipers and measure what is on your truck. Next option if you don't have a caliper is to remove the joint and take it in to the store and match it up by size.

 

Multiple U joints are listed because there are several different combinations of body, drive type, engine, transmission, and axle. Believe me, it's no different with Fords or Chevys or Toyotas.

In this situation, I would take the existing universal joints (driveshaft and all, if need be) to the parts store - that way, you have everything you need to answer these questions. At the very least, you're probably going to end up measuring your old stuff to get the right new stuff. A pain in the butt, I know, but sometimes that's how you gotta do it.

 

The U-joints mine took, they don't even sell at the parts stores. I had to get it from a drive-line shop. Mine were shaped weird. One cross section was longer than the other! You would be able to tell just by looking if yours are like this too. The guy at the shop said my drive-line set-up was an option from the factory. ??? Whatever I guess. Just glad I was able to find the right ones without buying a different yolk or drive-line.

 

This was one of those rare instances where a field trip to the dealership was in order.
According to the service writer, after getting her drunk I was able to appease her into spending 45 minutes looking up the information we needed.
Only the club cabs came optional with the aluminum drive shaft, unless it was an RT regular cab, then those could be ordered with aluminum.
The aluminum shafts used a 1.078" bearing cup with two different combinations; either a flat cup zerk (on the cup), or a standard zerk (inside the joint concave).
All the steel shafts (Detroit style for 1991-1998) used a 1.126" bearing cup.
All the N bodies use 7290 series Single Cardan joints in the rear shaft, whether it's 2wd or 4wd, and the front shaft at the transfer case uses a 1310 series Double Cardan joint while the joint at the front axle is a hybrid 1310/7260 joint.
I'm probably going to get reemed for this, but I got the parts at Autozone:
Rear shaft: 2-1175DG (x2)[7290 series]
Front shaft at transfer case: 1-0278DL (x1)[1310 series]
Front shaft at axle: 2-3100DL (x1)[1310/7260 series]

***The only 1991-1998 that would use a different rear U-joint is if it came with an Aisin Seiki transmission, thus a different drive shaft.***
The chick was adamant on the years 1991-1998, not 1991-1996, but I'm not positive.

 

These hybrid joints for the front are like that a little.
Axis one is 2.1" across and axis two is 3.2" across.

 

I'm going nuts trying to figure out the joints I need for the aluminum-graphite rear driveshaft on my '93 Dakota LE Extra-Cab AX-15 5-speed. I've got the front all set (I'll post part numbers soon), but as near as I can tell, the rear u-joints are INSANE. I think I need conversion U joints front and rear. 1310, 1330, 7260, 7290....this is driving me crazy. I've measured but I think I need to measure again, because things aren't matching up to what is available. I NEED to find this out, so I will post up with answers eventually, if someone else doesn't do it for me.