History: I did my motor mounts recently and the noise started there, although it was minor. THEN, my stock rebuilt driveshaft failed, upon inspection the center ball bearing exploded, the bearings were coming out of the little grease pinhole in the bottom of it. After that failed, the noise got exponentially worse. Swapped in a new HD driveshaft, no more vibrations, just a whining noise on deceleration. Then today, I heard a whirring noise, which to me sounding like a dry bearing. I also heard a random clunk at low speed on deceleration, which could lead me to believe it being the transfer case, but still not sure as some people say just happens.


My thoughts, I know its not the driveshaft It was installed probably 3 days ago, I know I have oil in both T-case and Diffs, so it's has to be a bad bearing somewhere. How would I pinpoint this noise? I'm unsure if I pull the driveshaft the noise will go away, because the diff and the t-case are still going to be spinning.


All input will be appreciated greatly,
Dane.

 

Hi Dane,
You may have had all those noises all along and they were masked by the failing stock drive shaft.

Plus you are LISTENING for noises now - listening for failure - so any noise you hear now is bad.

The deceleration noise may be the transfer case.
Might be time to pop the fill cap and see if there is 90 weight up to the line.

Check the diffs too.
Otherwise bet you are ok.

If you have aggressive tires, those can whine too.

 

Thanks for the input, but I always listen to the truck and fix noises before they turn into mandatory repairs, I know whats good and bad, and this is definitely a bad noise. I'll try to make a video of the noise. The noise became apparent after doing motor mounts, then increased after the shaft failure, and the oil level is full.

 

My suspicion is that you made an error while doing the motor mounts, and you have some direct contact somewhere between the engine/drivetrain and chassis.

I made a mistake a while ago, changing the transmission mount on the 5 speed on the TR8. I got tons of transmission whine through the body. The gearbox was touching the mounting plate, instead of being cushioned via the rubber mount.

 

It sounds like a bearing, no mistake in the motor mounts. They are installed properly for sure.

 

Discovery II drivetrain whine. - YouTube


That's the noise from 70mph coasting/braking to a stop, I feel a vibration on the freeway also now, only on acceleration at freeway speeds. Crappy video though, it really tones down the whine, its quite loud in the truck.

 

Ok got it figured out.
You put in new engine mounts..
From land rover???

Probably OEM or worse.

I am thinking these raised the engine and the transmission mounts are also bad and tilting up the engine via the engine mounts make the transmission touch the chassis directly.

This sounds like gearbox to chassis noise transfer.

actually sounds like the transfer case may be hitting the chassis.
If you hit bumps, ,you should hear some pretty good whacks to your chassis by the component which is in contact with it.

 

you say the noise will go away with out the front shaft in place? I check the out put bearing on the transfer case

 

Noise lessens w/ no shaft, it's the front diff. The transfer case is not hitting the chassis, motor mounts are genuine, and not larger. I honestly wish it was my output bearing, because I could fix that for cheap and relatively easy with the case still in the truck, but alas, it's the diff, I found a used one.

 

When i jacked the truck up for the motor mounts the shaft was still in place. It's supposed to slip but with the lift and angle it was being pulled I'm sure it stressed the diff enough to start the whine, then when my center ball failed the vibrations from that finished the diff off.