Gears & Axles - conversion u-joint problems, pics inside.

I am installing a 9" rear end in my car, it has a 1310 pinion yolk on it, using a aftermarket drive shaft with a 1350 on the end of it. I purchased a precision 348 which is a 1310 to 1350 conversion, but it seems the 1310 end is too short to be held in the pinion yolk securely. Am I missing something easy here? I have never installed u-joints before. Shown in the pics is one side held securely in place and the other side which is too short. Please help!

Yes, you are correct this is not the correct u-joint for your application. The u-joint should go all the way out to that little holder tab at each end to help center it. Are you sure the rear is not a 1350?

Well I bought it used so it is hard to say exactly, but the diameter of the caps on the 1310 side fit well in in the yolk on the rear end and the 1350 diameter is too big. The dimensions of the joint I have in right now are
Bearing Cap Diameter (in) Axis 1 1.063 in.
Width Overall (in) Axis 1 3.218 in.
Bearing Cap Diameter (in) Axis 2 1.188 in.
Width Overall (in) Axis 2 3.622 in.
I guess I just need to pop the drive shaft back out, take measurements of the distance between the tabs, determine if the cap should be 1.063" or 1.125" and start shopping again?

this is info I found try it , it may help
Johnny

"Typically, a Napa 447 conversion u joint is what is needed to use with the factory driveshaft, to match it up with a 1350 yoke. With the Moser 9 inch, the driveshaft will be one inch too short. Many people never have a problem, but several people picked up a vibration due to the driveshaft being too short. The longer yoke that has been posted above will take care of the problem, although the factory aluminum and steel driveshafts are prone to breakage. I've seen them turn into a pretzel on the starting line, and they normally take out the exhaust and put holes in the floor before they quit spinning. This happened to my car with an aftermarket driveshaft, I then went to a PST 3.5 inch aluminum driveshaft that uses a 1350/1350 u joint, and I have never had to worry about the driveshaft since then. Here is a link to the PST driveshaft. http://www.exoticperformanceplus.com....html?item=541"

good luck

What you need is a 1330 to 1350 U joint conversion, not a 1310. The 1330 is slightly longer with the same cap diameter as 1310.

http://www.summitracing.com/parts/STR-U1647