cmp truck

Hi all,
I had the front driveshaft on my 2002 Cummins replaced last year.
There is a grease nipple on the shaft.
I pumped grease into it during the spring maintenance, but no old grease squeezes out as it would when you grease a balljoint.
How do you know when enough grease has been injected into the driveshaft.
On an aside, when searching for this issue, I read all the posts on greasing U-joints. I had all my u-joints replaced with u-joints with grease nipples when it was time to replace them.
The bad joint is the compound u-joint just in front of the transfer case.
My mechanic told me Chevy has grease nipples on theirs, but Dodge didn't put grease nipples on theirs.
When this needed replacing, he put in a u-joint set with nipples. The only hassle is greasing the one joint as the transfer skidplate is in the way.
Ian