I recently swapped in a new to my Bronco D44 (from a 78 going in my 79) but the pinnion yoke on the axle accepts a bigger u-joint than my driveshaft has. The driveshaft is as old as the bronco so I will have it rebuilt to accept the bigger u-joint. How do I measure the yoke to find out what u-joint it accepts? And what else will I need to tell who ever I get to rebuild the DS? Thanks

I've never had to tell the driveshaft places what to do here. If you have a different yoke on it they should be able to put the right joint in there and fix everything up. We are taking my brother jeep down and bringing a 1410 for the axle and a 1350 for the tcase and having them do the rest. I forgot the part number of most front driveshaft for fords and chevies. It is basically the same. All old chevies and fords. Some yokes are interchangable also.

measuring the yoke would be inside the ears that hold the caps on. you know the ones that always break off.

Make sure you take a center to center measurement at yoke for driveshaft lenght as I'm assuming there may be lift on this unit. Conversion universal joints are also available that would have 1410 one side and 1350 on the other side of the cross.
Another solution may be to swap the yoke on the diff, as it may be the same depth/spline and then everything will be normal. As LL said the driveshaft shops know what to do.

the '78 Bronco used 1310 u-joints and the 79 used 1330. Or was that the 351M used 1310 and the 400 used 1330? Anyways, it's probably a 1330 yolk. Take the yolk off the old D44 and stick it on. This is a common upgrade that people do for bronco drive shaft strength for those years.

I don't have the old d44 anymore. So who ever I get to rebuild the shaft would know the sizes? No lift here so it would still be stock length. I'm still new to all this so thanks for the replies and patience.

I wouldn't rebuild the driveshaft just for that, I would go find a yoke at a junkyard and slap it on the dana 44. Shouldn't be too hard to find. Even up here in Whitehorse it only took me 5 minutes to find a whole 3rd member for the rear end on my truck.

It's as old as the truck and I don't want it letting me down at the Rally.

If your worry is the strength of the part, then I would definitely upgrade the yoke on the D44 to the 1330. If you are going to get the drive shaft rebuilt it makes no sense to downsize the u-joint to the 1310.

The d44 has the bigger yoke, sorry if I wasn't clear on that.

Sorry, my mistake.

No worries, thanks for the help anyway.

Why get the shaft built? do you not have one? I probably have one kicking around that will fit , 24 Coors Light should do it.

The Bronco is gone now. Thanks anyway.