I started hearing this hum after i'm going about 20mph or more and it is only when steering wheel is turned left. It will even hum if truck doesn't lean when I turn. Front bearings have been replaced. The rear diff cover is coated in grease which I don't see how that is possible. If it was leaking I would expect fluid on the ground after sitting overnight. Also, there is no vibration. Hoping to fix whatever it is this weekend.

 

Ok but your Dakota what year engine so on is it?

Did you check the Diff oil level?

What front bearing are you talking about you mean new Hubs?

Oil can drip out only as you drive you do know that?

If I sound blunt sorry I just crawled out of bed.

 

2000 3.9l. Front hubs were replaced and hum is still there. I'm checking the diff level soon as I can, working right now. I didn't know it would only drip when driving. As far as the grease on cover it kind of looks like it seeped out the drain plug then went in a circle around it to cover almost the entire cover. Just read that one some vehciles the motor mounts can break and cause engine to vibrate against frame.

 

Those plugs are rubber and dry out and shrink letting oil get out, I opened my diff cover plate and cleaned it and put it back together and put only 2 quarts of oil in that’s shy 1/2 a quart and it hummed till I put the full amount in it then it got quiet.

 

It's just got me wondering if the fluid would move that much just changing lanes. It will hum when I switch lanes for a sec then soon as wheel is straight its quiet.

 

take a look I have a thread on pulling my Diff cover off cleaning the Diff out putting the cover back on and re filling it with some pic's this was back in Sept 2011 it was my first time doing it so I wanted some help.

You can get new Diff plugs in most auto stores I used a gasket and the ATF gasket sealer on the cover plate I think that’s what it’s called it was easy and fast.

 

Inside the Diff is a very large gear the ring and it slings oil all over the place it’s submerged in oil all the time that’s why it may only leak as you drive.

The hum is low oil


This may not even be whats wrong but its a start.

So pop the plug and check the oil level if oil seeps out it ok but if not stick a finger in and feel how low it is

 

If you ever saw.. back in 09 is when i sucked old fluid out then put new in. I had posted on here lol. I should have changed plug back then maybe.. any idea where to buy new drain plug? Mines the rubber one.

 

Autozone has them

 

Any idea if they also have exact fit pcv grommet? mines hissing no matter what pcv i buy. I did just put a hose clamp on the hose and it seems quiet now, but with all the miles I have id like to put new grommet just for peace of mind. I can't check too many sites lol for car parts right now. They record my screen at any given time lol and when i'm on call with customer. 170000 miles(only been in shop for alignments and busted hoses)