Greasing Universal Joints

[david.g.chapman]

I have had trouble in the past getting all the bearings cups to purge with fresh grease when lubricating. I have pumped nearly an entire tub of grease through two of the bearings, but the other two just show a tiny amount of black grease.

I have tried heating up the joint - no luck, and using a grease forcer from Frost - also no luck.

I could try:

1. Forcing oil (or another solvent) into the joint to clear the blockage?

2. Waggling the joint with grease pressure applied?

I am not confident this will work. The bearings have no play, and have been working well for 30000 miles like this, incidently. I do not want to remove the propshaft unless I really have to.

Any ideas?

Dave Chapman.

[alexblack13]

Hi Dave,
I find both of my prop bearings do exactly the same. Fluid (Grease!) will always take the easy route as you have found. Doesn't necessarily mean you have a blockage. I had the prop shaft in my hand when I checked and greased the u/J's and the grease still took the quick route. I just gave it a few full deflection moves and applied some more. A good wiggle and fitted it. I would not remove it if its OK. Just give it a few pumps every service and let it find its own way in. It will do so. Probably. I've seen new ones do the same.

Don't panic. if its OK run it till it gives grief. Don't fix what is not broken... as they say.

Happy days!

Alex B....

[david.g.chapman]

Thanks Alex.

Biassing the joint one way, and then the other while pumping might be helpful.

Dave.

[GrUmPyBoDgEr]

Have you checked for some end play in the joints?
There should be some.
The usual procedure after fitting new UJ's is to give them a light "clout" with a mallet to ensure that the bearing cups are at their most outward position i.e. abutting with their retaining Circlips.
The cross shaped UJ itself is drilled centrally through all 4 legs to where they join up with the grease nipple bore in the centre.
Perhaps if there is no or too little end float the flow of grease through that pair of UJ bearings will be more restricted than the other pair.
As Alex mentioned the new grease (or oil as you have suggested) will always seek the path of minimum resistance.
On the other hand, grease can solidify & subsequently restrict flow for fresh grease, in which case a UJ Bearing failure could happen at some time.

Hope you sort the problem.
John

[david.g.chapman]

Interesting point about the end float, John.

I will have a go this weekend, and will let you all know if I come up with anything useful - otherwise the propshaft will be coming out in the next 10000 miles...

Dave.