Took a short trip the other day and I noticed that when the engine is pulling, such as a slight incline, I'm noticed a very slight vibration that I can feel through the steering wheel. It goes away immediately if I let up on the accelerator, or the ground levels out. My only thought is it would be a u joint going bad. Any other thoughts out there???
Get it greased and inspected.
You could be dropping a cylinder. Clogged filter, etc. Have had this symptom on hills with several MBZ diesels. Was primary filter. How is the power on hills? Filters that are starting to clog don't show their hand at first on the flat but wait for higher power applications.
If you are underneath, look for red rust colored dust around any part on the U joint. When they are dry they may leave a tell tail indication. Failure here can be expensive if they come apart otherwise just a replacement.
U bet, I had a loose cap on a 1810 U Joint, let the cross move off center during a pull, vibration indeed, was simple to fix, torque the 2 bolts on each side and lock, bend tabs up. Had been changing engines, transmissions and cutting drive shafts so often and forgot to proper lock one down. Just for grins, with the 12V-71 and RTO910, the driveshaft had to be 9 1/4" between joint centers WITH the slide, the slip section was very short but very large in diameter, larger than the 1810 joints. Can assure U, a loose/bad joint will surely vibrate when pulling, when coasting ,very smooth.. We all know how I found that out.
Filters were all changed within the last 5000 miles so would expect they're okay. I'm in eastern North Dakota so the highest hill is roughly 10 feet, not much of a test. So guess I'll be crawling underneath someday soon. I do have the safety posts.
Where do I find the part number/manufacture, whatever to get parts? I checked it today, no problems that are visual, but there is a slight amount of play in one of the crosses. I assume the whole shaft has to be removed to work on it.
There is a slight amount of movement in a joint, but hard to determine. I would grease the joint, pump until you see grease from all 4 bearing cups. A dry joint can vibrate too.
Another case of experience where I thought the shaft was out of balance, nope, needed greased, so greased proper and no more vibration.
If greasing gets rid of the vibration, I would most likely pull the joint cups, one at a time to check condition of the cross and the needle bearings in cup. Some damage could have occured.
Some things I gotta know on my toys. Also I would guess the joints are the Spicer 1710 series.
Look for casting number or if you have a set of calipers, take measurements. NAPA truck should be able to x ref with measurements if no number visible on joint. Some with clips are easy to R&R. Dave will know that better than me.
If bearings have been dry for long, they will leave wear marks on the cross where each needle was.