sawguy50

Transmission in neutral. Pinion not turning. Same sound at both wheels.

skypilot

iTrader: (1)

Bad wheel bearing.....................

Lose it fast! That can hurt you.
takes special tool to R&R the axles bearing.

sawguy50

Do you think both sides would go at the same time? There's no play in the wheel at all.

maachine

nope. i dont think both would go at the same time. were both wheels off the ground when you spun the wheel? or just one. if it was just one, pinion should have turned if you were in neutral.

does the truck drive? whats it sound like when accelerating? then what does it sound like decelerating?

skypilot

iTrader: (1)

Nope; they usually fail at different times.

sawguy50

Both wheels were off the ground. I could see the driveshaft not turning.

I've been chasing this noise for 6 mos now. First thought it was the front diff. It makes a howling sound loudest at 40 mph. Accelerating or decelerating. Higher pitched at higher speeds. Since I am by myself, it's hard to spin the wheel and use a stethoscope at the same time.

Buckaroo5

Responded to your post on t4R. Get it up to speed and swerve slight left, then right and back again. If it is wheel bearing, you should hear the noise come and go as you load and unload the bearing. You can put it on jackstands and run it up to 40mph, then get under it with your stethescope and check both wheel bearings and rear diff (Obviously Be Careful). Based on your description of the noise, this sounds like pinion bearing. I had similar noise and the pinion bearing was the culprit. Confirmed it using the method I described. You really want to be sure before you tear into the diff.

Buckaroo

sawguy50

The pinion wasn't turning in the video. Both wheels off the ground and in neutral, so I eliminated the pinion brg. I tried the swerving and it doesn't change anything. I replaced both front brgs about 3 mos ago. Do the spider gears turn when I'm spinning the wheel?

Buckaroo5

I don't think the clicking in your video with the wheels turning is associated with your whining. I think the clicking is a normal sound that comes from the spider gears turning in the diff. This happens when one wheel spins faster than the other. They aren't made to turn a great deal, just a little when you go around a corner and the outside wheel turns faster than the inside wheel. When one wheel is turning and the other doesn't at all, those spider gears are moving relatively fast - hence the clicking.

So you got no change on the noise swerving - I did not either on my pinion bearing issue. Also, a wheel bearing noise is typically a lower frequency noise - often described as growl or grumble. Diff noise is higher frequency and often described as a howl.

But you want to be sure....I chased my noise for a couple of months, used the stethescope with the truck on stands and still wasn't 100%. But, the wheel bearing noise was the same on both sides. The Diff itself is noisy normally but I was getting a pronounced whine from the nose cone just inside the companion flange. I had no metal in the diff fluid but, after disassembly, I could feel that the pinion bearings were noticeably rough & could see the pits.

Buckaroo

Buckaroo5

Also - if your noise changes on or off the accelerator, that is typical of ring gear/pinion gear issues. You didn't have that - I think you said yours did not change. So maybe you think that means it's not the diff....but that is typical of the pinion bearing.

Buckaroo

sawguy50

The noise doesn't change either speeding up or slowing down. However when coming to a stop at around 10mph it feels like a real heavy mud tire in the brake pedal. This is why when I spin the wheel it seems like the same vibration.

maachine

i say open up the diff and take a look. i doubt its your wheel bearing and it has to be something inside the differential.

Buckaroo5

Don't know what mud tire means....more info please. Also, I would expect that the volume and pitch of the noise would get higher as speed increases from say 30mph to 60 mph....does that happen? Does the noise change with the speed of the truck or the speed of the engine?


Some question...have you checked the fluid level in the diff? Have you in the past and was it low? Have you changed the fluid? Any metal? Are your axle seals leaking on the rear wheels? Maybe you have said and I did not pick up on it but what's your mileage and how long have you had it? Also...this is not an e-locking diff, right?

Buckaroo

Buckaroo5

Sawguy - I see you had a thread a while ago on this to which I responded....don't remember what all was indicated in that thread so sorry if I am asking the same questions....
Buckaroo

sawguy50

Mud tire sound means same as rumble strip sound. It's always there accelerating or decelerating, but only when you get down to about 15 to 10 mph. Yes, pitch does change when going faster, it goes up in pitch the faster you go. Not engine speed but mph speed.

sawguy50

Ok, I checked the diff fluid level, it's fine. Did not check for metal filings. The axle seals are not leaking, does not have an e locker. Had new pinion bearings done about 30k ago.

Buckaroo5

So let me summarize what I think you said.....the whine is always there, decelerating or accelerating and it changes pitch with the speed of the truck. Then you have a mud tire rumble sound that starts to occur around 15-20mph as you apply the brakes. When you hear the rumble sound you can also feel the brake pedal vibrate. Do I have all that correct?

If you just slow down to a stop without applying the brakes, do you still get the mud tire rumble sound?

Is it possible that the brake pedal vibration and the rumble noise is the anti-lock brake system kicking in?

Buckaroo5

Why did you replace the pinion bearing....did you have noise?

When you did the pinion bearings, did you do both the front and the back? Did you replace both the bearing and the race on both of those. Did you do the two side bearings in the diff as well?

skypilot

iTrader: (1)

A whine at 40mph is pinion bearings. So from what you are describing, you need a major overhaul.

http://www.marlincrawler.com for the win.

sawguy50

I had the pinion brgs replaced about 75k miles ago. I bought a stethoscope so today I'm going to try and narrow it down. Another interesting fact... when driving down the road and I hit a gradual dip, the noise intensifies for that brief moment. Like added weight pressing on a component. Wouldn't that point to axle brgs?