u-joint question

[bootlegger]

I'm replacing the front axle u joints in my xj.
In the past, I've never been a fan of greaseable, but that's always been in my trucks that never got that dirty.
Crossing creeks and stuff in my xj has me wondering if I should use the greaseable style.
Any opinions?

[biggin69]

IMO, greasable joints are weaker than non-greasable because they are drilled so the grease can get to the caps/roller bearings.

[WrenchMonkey]

Not just his opinion, that's a fact.

Sealed (non greasable) is the way to go.

Robert

[blazerbrad]

Non-greasable (solid) u-joints are stronger than greasable (drilled), but it is a very, very small amount (assuming all else is equal). When you drill the small grease channel in the middle of the round cross-sectional area you simply don't decrease the strength of the part that much. Same calculations for determining the strength of tubing. If you have 1" tubing and go from .125" wall to .250" wall you have doubled the wall thickness (increase by 100%), however the strength only increased by around 35%. In the u-joint the equivalent wall thickness between a greasable and non-greasable is probably only around 15% different which would equate to maybe a 5% difference in strength. 5% is 5% but in the real world if you broke a greasable u-joint on the trail there is a good chance you would have broken the non-greasable version in the same situation.

[bootlegger]

Thanks for the input. I'm going to get non greaseables.

[Drivermod]

I'd go greasable and put a shot of grease in them everytime you go on a ride. The joint is more likely to fail from contamination than the slight decrease in crossectional strength.