What is this whining/whirring noise? (YouTube link) (1 Viewer)

[eagleeyes170]

1999 LX470

I was driving on the highway one Sunday evening and this noise suddenly came about

Recent work:

- replaced both front CV axles

- greased all the axle/shaft fittings.

- replaced both front wheel bearings

- drivers side CV axle seal was also replaced

- the front diff was also replaced 6 months previously by previous owner (i have receipts)


I was told this could be a rear pinion gear issue as well. How can I tell if the noise is coming from the front or rear?

 

[Spike555]

How many miles are on it?
If the front diff went out from lack of maintence the rear diff will be in similar condition.
Changing the diff fluid will help a little if it is not to far gone. The noise will still be there but you can basically stop any further wear.
Like all oils, once they wear out they do not provide lubrication and things start tearing themselves apart.
You will know for a fact if it is the rear pinion by changing the fluid because the nose will be less pronounced.

 

[eagleeyes170]

How many miles are on it?
If the front diff went out from lack of maintence the rear diff will be in similar condition.
Changing the diff fluid will help a little if it is not to far gone. The noise will still be there but you can basically stop any further wear.
Like all oils, once they wear out they do not provide lubrication and things start tearing themselves apart.
You will know for a fact if it is the rear pinion by changing the fluid because the nose will be less pronounced.

The truck has almost 250k miles. It ran silent and smooth, then one day the noise suddenly appeared while i was driving on the highway. I hear the noise more in the front, but you are right it could be in the rear with noise transmission. I think I will start with rear differential fluid change and see where that goes. Do you have a step by step instruction on how to rebuild the rear differential?

Also....Wyoming, MI???? you are 10 minutes from where I live! do you know any good shops in the area? I have little time/tools to work on this rig myself.

 

[Spike555]

Went back and watched your video again. Saw some familiar sights!! The Amway building for one.

No, I do all of my own work. I have never needed to rebuild a diff so I can't help you there.
But I can tell you that you can run the diff like that next to forever if you're willing to put up with the sound and change the fluid as soon as the sound changes.
Using a 85w-140 gear oil can really quiet down the noise.
A proper repair is a rebuild or a new diff. I can give you the name of a good auto salvage yard.
And the place that rebuilds i can tell you where commercial trucks go to get diffs rebuilt but not passenger cars.

All of this is assuming it is the diff going bad.
The way to test it would be to remove the rear driveshaft and with the truck in the air run it up to speed, is the noise gone? Yes? Remove front driveshaft and install rear, repeat. Noise still gone? No? Rear diff.
It could be tires. If it starte all of a sudden low tire pressure can make different sounds.
Could be the transfer case too.
It is really hard to say for sure by just the video.

 

[eagleeyes170]

Went back and watched your video again. Saw some familiar sights!! The Amway building for one.

No, I do all of my own work. I have never needed to rebuild a diff so I can't help you there.
But I can tell you that you can run the diff like that next to forever if you're willing to put up with the sound and change the fluid as soon as the sound changes.
Using a 85w-140 gear oil can really quiet down the noise.
A proper repair is a rebuild or a new diff. I can give you the name of a good auto salvage yard.
And the place that rebuilds i can tell you where commercial trucks go to get diffs rebuilt but not passenger cars.

All of this is assuming it is the diff going bad.
The way to test it would be to remove the rear driveshaft and with the truck in the air run it up to speed, is the noise gone? Yes? Remove front driveshaft and install rear, repeat. Noise still gone? No? Rear diff.
It could be tires. If it starte all of a sudden low tire pressure can make different sounds.
Could be the transfer case too.
It is really hard to say for sure by just the video.

Would you tell me about the place that rebuilds diffs for commercial trucks? The salvage yards I know about in the area are Weller and LKQ, are there other good ones?

 

[DTCsk8er]

I've seen an 8in Toyota rear diff make this sound w/ a bad pinion gear. Letting off gas it sounded fine, but as soon as you put a load back on the pinion it whined. Oil in the diff was dirty, but rotating the pinion by hand it felt gritty. Rebuild kit for these are reasonably priced, however it requires special tools and knowledge. I took the plunge on buying all of the tools several years back, and they have paid for themselves by now at least 2x over. Zuk's site (Toyota Gear Install Harrop) is an amazing resource for going this route.

How confident are you that the front that the PO replaced was done correctly?

Jack it up, remove rear shaft, and spin by hand. If still in doubt, removing the rear 3rd member isn't too challenging.

 

[Spike555]

Would you tell me about the place that rebuilds diffs for commercial trucks? The salvage yards I know about in the area are Weller and LKQ, are there other good ones?

Weller Reman, Valley Truck Parts, State Spring used to do them, I do not know if they still do.
Frontier Truck parts.

Dorr Auto Salvage, talk to Bill, tell him FedEx Phil sent you.

 

[Spike555]

Also, a good driveline shop is Bob's Transmission, that's who we use for our transmissions.
Tow the van to the shop in the morning and drive it away that afternoon.
There are several around the greater GR area, they are all owned by the same guy and all do the same quality of work.
I'm not saying they can do your diff that quick, just saying they can swap a transmission that quick for us.