DP U-Joint Maintenance & Lifespan?

[CVD]

I was underneath my 1999 Freightliner XC chassis (looking up air dryer part numbers) and noticed zerk fittings on the u-joints. This rig is 14 years old, with 50k miles; I doubt those u-joints have ever been looked at or serviced. Two questions:

1) I assume I should shoot a pump or two of grease into them. Should I use the same ‘High Moly” grease that I use for the jeep?

2) I did a quick search and didn’t find much on DP u-joint issues. Is there a point (years or miles) where they should be changed as a preventative step?

[RayChez]

I always make sure that the U Joints and the spline gear gets lubed. You can tell if they need replacing the u joints start making a clicking sound. Like somebody mentioned that I am sure it has been lubricated because they would not last fifty thousand miles. Get a grease gun and lube every zerk fitting you can find.

If you lube your U-Joints proper, they will last a long time.

[randallb]

Most diesel's have a 5,000 mile grease interval for the driveshaft u-joints. A u-joint cup accelerates and decelerates 64 times/revolution. This accel/decel cycling does not change with driveshaft length. I would replace or have the u-joints replaced and then check the pinion angle to make sure your engine or trans mounts (if you have any) are not sagged. You want the angle difference to be 3 degrees or less. Why replace what may be good u-joints? Because if you do not you will have that nagging question bouncing around your head, harshing your mellow, as you drive down the road.
Randy

[sjholt]

I replaced my u-joints at 125k and they needed it.
The driveshaft is really short and turns really fast so I grease every 2500 miles and I keep pumping until I see grease coming out of all four cups. You have the 2 U-joints and the shaft slider that need grease.

[slickest1]

It wouldn't have lasted 50,000 miles without being greased! How long have you had it and how many miles have you put on it? I would have them checked soon!I grease mine every 2 or 3 thousand miles.

[wny_pat1]

Not just those U-joint zerks, but you should have several more zerks on your chassis. You should get it lubed at least one a year. And make sure you use the proper grease. Mixing grease is worse the mixing oils! And if you have Meritor brakes, make sure the proper clay based grease is used!!!

[pusherpilot]

CVD wrote:
I was underneath my 1999 Freightliner XC chassis (looking up air dryer part numbers) and noticed zerk fittings on the u-joints. This rig is 14 years old, with 50k miles; I doubt those u-joints have ever been looked at or serviced. Two questions:

1) I assume I should shoot a pump or two of grease into them. Should I use the same ‘High Moly” grease that I use for the jeep?

2) I did a quick search and didn’t find much on DP u-joint issues. Is there a point (years or miles) where they should be changed as a preventative step?

CD, According to most user manuals those should be lubed every 5-10k along with the rest of the zerks on the chassis. As it is I scrapped the ones in my 2000 Safari after about 25k and they had been lubed according to the book. Check with Freightliner for frequency and type of grease to use.
My 04 Imperial has 100k on it and the joints are going strong. Nothing in the manual about changing them.
Ron (Former Circle City resident)