Rear slight hum: Tyres or Diff

[jayfrem]

Bi There

I am running 285 75 16 BFG AT like many of the guys. LC 100 is a 1999 with 140 k miles.

On the highways at deceleration , radio off i do hear wind noise / slight hum.

Could this be from the larger tyres or rear diff pinion bearing ?

 

[Sandroad]

Grease the rear driveshaft and see if that helps. If not, then rotate the tires and see if the sound location change. Diff bearing failure is so rare it's very unlikely to be the noise.

 

[TXLX100]

You can run your hand lightly over the tires and feel if there's any chop or unevenness. My BFG KO2's are pretty quiet on my other Toyota.

 

[jayfrem]

Thanks guys....will check the greasing on rear drive shaft.


Could 140 K miles without diff oil change damaged any bearing / gears ?

 

[DirtDawg]

Unlikely, but you should change it ASAP and it will also show any shavings/wear from your rear diff.

 

[jayfrem]

Hi There

Changed my rear diff oil.....the " hum" sound is there....you hear it in highway above 50 MPh ( 80 km/hour).
The oil was clean.

It sound like a bearing pitch at certain speed....
The truck has AHC ( all running smoothly).

Could it be a rear weel bearing ?

Pls help.

 

[jayfrem]

Hi there

I am thinking to investigate slight hum if from Diff or Wheel bearing....is it a good idea to take off the rear transmission shaft and test drive on highway ?

If sound stays this means it is rear bearing since transmission shaft will be out.

Pls advise.

Jay

 

[taco47001]

Very likely could be a rear axle bearing.... with the noise comes added friction within the bearing which causes heat...the heat will eventually cause the seal to fail and then comes the goopy, nasty, runny mess of diff fluid leaking out and onto the inside of your rim and on the floor... Happened to me on my Tacoma I had previous to my LX.

Find a shop that can press the old bearings out and new ones in. Remove your rear end yourself and deliver it to the shop...you'll save yourself boucoup dollars.

 

[taco47001]

Very likely could be a rear axle bearing.... with the noise comes added friction within the bearing which causes heat...the heat will eventually cause the seal to fail and then comes the goopy, nasty, runny mess of diff fluid leaking out and onto the inside of your rim and on the floor... Happened to me on my Tacoma I had previous to my LX.

Find a shop that can press the old bearings out and new ones in. Remove your rear end yourself and deliver it to the shop...you'll save yourself boucoup dollars.

 

[jayfrem]

Very likely could be a rear axle bearing.... with the noise comes added friction within the bearing which causes heat...the heat will eventually cause the seal to fail and then comes the goopy, nasty, runny mess of diff fluid leaking out and onto the inside of your rim and on the floor... Happened to me on my Tacoma I had previous to my LX.

Find a shop that can press the old bearings out and new ones in. Remove your rear end yourself and deliver it to the shop...you'll save yourself boucoup dollars.

Thanks a lot.

Will take out that rear drive shaft and test drive.

Jay