Thread: Problem greasing greasable uni joints

i had the same problem, so for those two nipples i use one of these.

https://www.whitworths.com.au/main_i...AbsolutePage=1

the rest i use the normal gun.

You could pull the nipples out and try putting some grease through them, it is common for nipples to block/fail.
Uni joints have a long service life thats why many dont have nipples, they are a lot like a pre packed bearing.
As the grease heats up centrifugal force pushes the grease into the needles.
If your nipples are free flowing and you dont get any grease coming out the dust boot it shows that your dust boot is in good condition so it is unlikely that any contamination has got in.
If you have a decent grease gun it will be capable of putting out over 5000psi.
To really put your mind at ease i would mark the position of your prop shaft/pinion flange and remove it, hook up your grease gun and articulate the uni while under pressure.
The advantage of removing them is that you can feel if the uni is stuffed by articulating it in your hand.
JUST REMEMBER THOUGH to much pressure and you may dislodge your seals then you will be greasing it all the time to push the contaminants out.