Maybe it's humming because it doesn't know the words. Okay, bad joke but I've been here long enough people are sort of used to me now. First off, what are you driving and how many miles on it? Have you pulled the front shaft and wiggled the joints? I would pull the front shaft and check both joints on it. If one is dry or getting stiff from wear, you can get a sympathetic harmonic in the shaft tube. This could sound like an old Mazda commercial from the early 80's. "Piston engine goes boing, boing, boing boing. Mazda engine goes Hummmm!" Yes, I'm old. I remember when the Wankel rotary engine was in more than the RX-7.

I'd check the front shaft first. I would pull it but you can pull one end. Work it around and feel for binding or stiffness. I'd also check the splines on the front shaft and make sure it is greased and slides smoothly and the splines aren't loose. I've seen them run dry and wear the splines down. That can cause slop in the middle of the shaft.

 

Haha i got the joke 🤣 and wenkels are a cool concept and sound like angry lawnmowers but theres a reason why they arent very popular among manufacturers.

I drive a 1998 ram 1500 extended cab with the 5.9L @ 192k miles. I plan on doing the driveshaft seals front and rear first along with U joints cause i hear a deep "wump wump" when driving on top of the tire noise. Ive already checked wheel bearing to make sure that wasn't making the noise.

I will check what youve recommended most likely in the spring or whenever it warms up. Its been cold as the frozen chosin here in ohio, hence why i noticed my 4wd making noise. I limit my 4wd to emergencies and when i truely absolutely need to use it, since im concerned i might break it

Thanks

 

Since you may have wear on some joints, press your foot on the brake solidly and move your shifter, with the engine running of course, from drive to reverse a few times. You want to listen to a THUNK when is changes direction. This will sometimes tell you about a bad u-joint in the rear driveshaft. Those cause havoc when they fail. The rear one will just let your driveshaft fall out. The front one will flop around and beat the snot out of the bottom of your truck.

 

Well thats scary. I thought the thud was normal, going from drive to reverse.

the true price of an $800 truck . 🤕

 

For $800 and it runs, you got a good deal.

 

I expect to hear some noise on a 4x4 truck when changing direction, or going from park, to any gear. Its just the driveline taking up all the slack that is normal for such drivelines.

 

$ 800 non running. Didnt run and drive once warmed up. Seller thought tranny was toast. Looking at this forum, all it needed was the gov solenoid and sensor. Got it running in no time. Now i got all these problems on top of 3/4 wheel bearings.

But ive put too much effort to sell it. After doing front wheel bearings, front axle u joints, plenum gasket, distributer and rotor, water pump, etc.... all in less than a year. At this point, im gonna drive and maintain until its completely done for.

 

So the thud, regardless 2 or 4 wheel drive, when going from drive to reverse is normal?

 

To an extent. I would have to hear it to tell you if it's excessive or not.

 

Grab the end of the drive shaft and wiggle it. If you can see movement on the joint, it's shot. Both ends can wear. Now, if in neutral and not running (set the brake and block the wheels) you should NOT be able to rotate the drive shaft where it goes into the rear pinion. If it does that, you have bigger issues inside the differential.