Chevrolet Other

1999 AWD Chevy Astro van- 130,000 miles. I just replaced both cv shafts with new units. The swap out seemed to go well, but I noticed the new shafts seemed to be about 1/2" shorter than the originals. After a successful test drive and an 100 hundred miles the cv shaft on the passenger side came out of the inner differential. I thought I had set everything in place. What am I missing? I reinstalled the shaft and tapped it in until it appeared to be up against the seal, but now I am concerned it will happen again. Auto store confirmed that this was the correct shart for the vehicle. Suggestions welcome.
Dodge coupe
January 2, 2007.

As a follow up- I haven't had a chance to check yet, but it has been suggested that I check the front motor mounts, for a broken mount, possibly on the passenger side. I'll check it this weekend.

Dodge coupe
Jan 4, 2007.
I did check the motor and transmission mounts. They are not broken. All other suspension components are within tolerance or had been previously replaced. The passenger side cv joint appears that it was not seated properly which is why it came out.

As far as the clunking noise which was not consistent, I found the clamp on the front drive shaft was loose which may have allowed grease to leak out or moisture to get in. I priced the cost of a rebuilt shaft and determined that it was outside of my budget at this time so I fillled the boot on the existing front shaft with grease and placed a new stainless screw clamp on the boot. It appears that the sllip yoke was binding causing the clunk.
Problem solved.

Dodge coupe
Jan 7, 2007.