I need help identifying an issue with a noise and slight vibration (I can slightly feel it in the floorboard) at 75 to 80 mph (interstate driving). Whether I have the truck in gear or put it in neutral at that speed the noise will not go away. I had the entire rear driveshaft and u-joints replaced a couple of years ago. I'm leaning towards a pinion bearing, but I don't know how to tell when a pinion bearing is bad or if it can be a wheel bearing. The truck is really smooth but acts a little erratic around this speed, then smooth outs again the faster I go. Please help

 

check your drive shaft for damage. It may have also thrown a weight, look for a weld with nothing attached. or shiny metal.

 

I would be hard pressed to think pinion, but maybe.

Jack up the rear, put in neutral...spin and listen/feel. you can also feel for excessive lash...take driveshaft in hand, rotate back and forth, like 1/4" to feel how much slop there is between the pinion and ring. also, push/pull on it. should be no play, i.e. bearing solid. if there is movement, your bearing diagnostic is accurate! good luck.

 

Check your u joints. For a ****ty u joint you can kill it in 2 years. Its the most simple thing to check, Block tires. Put truck in neutral and go rock up and down and side to side on u joints, If theres play thats most likely your problem.

 

Thanks for the help anybody. I originally had put a dent in the driveshaft while hunting so I had to put a new tube in. This is when the problems started. I have been putting aftermarket joints in and still the noise at the same speed range. Do you think sucking it up and getting the OEM Dodge joints would be the way to go? Better quality, longer life, etc. The OEM joints were fine till i messed up the shaft. Thanks

I got a driveshaft for a 99 Dakota like mine but I checked with the Dodge Dealer and the part number is meant for a 99 Dak only. Should I check if it would work or should I send it back and work with the one on my truck, like getting it off, new OEM (Expensive) u-joints and balancing it... again?

I have had this problem from the first drive after putting new joints, replacing the joints once more and the problem persists. Any ideas? I will spend the money for OEM parts. I just want to fix the problem. I treid to get a new OEM shaft but the shaft is discontinued go figure

 

If it started with a DS change, I would ask to have it re-balanced. Also, like the others, check pinion bearing slop.

 

Bet it needs to be balanced too.

There is a procedure in the FSM, I think it uses hose clamps. Or take it to a good driveline shop. OEM u joints probably won't matter, and in my opinion, the top of the line stuff from NAPA is better anyways.

 

BTW, where did you get the driveshaft you have in there now anyways? Junk yard?

 

The shaft in their now is the original shaft that got retubed. Original slip joint and rear yoke into the axle. New tube. I picked up the 99 shaft from the junkyard today and the part number on it is strictly for 99 only so I gotta send that back. I am going to have it balanced indefinitely.

I figure if the problem started after installing new joints, might as well start there.

 

If they didn't balance it after re-tubing it....that would explain it. Even if they did, machine could have been wrong.

dbilik, not sure, but i bet you're right, using the weight of the clamp as a balancing weight