U-Joint Mystery

[JerryBob]

I have a 2nd Gen Toyota Tacoma with 3 U-joints. One immediately after the transmission, one in the middle, and one right before the rear diff.

I grease them every six months, and I’ve always noticed that the most forward U-joint takes three pumps, the middle one two pumps, and the rear, next to the differential, one pump.

I’ve always wondered why the consistent difference. I would think that the torque would be equal all down the drive shaft. And since the rear axle is constantly moving up and down, if anything, the rear U-joint would require the most grease.

Can someone explain this to me?

 

[Oillover]

My guess would be the amount of articulation/movement. The forward one seems to articulate more and more frequently than the others.
Which is the opposite of my BMW, which wears out the rearmost joint first.
Just different designs.

 

[PontiacHO]

If there’s no grease leaking out, you reach a point where very little grease can be pumped in.

 

[zfasts03]

Is the most forward one close to exhaust components warming it up more than the others?

 

[Oliveoil2]

What is your 6 month mileage? Do you grease after the drive line is warmed up?

 

[Marcozi]

What grease are you using?

 

[Ursatdx]

Would the foremost zerk on the rear axle also service a slip yoke or forward spider?