Grinding wobbly howling noise when accelerating

Hi and thanks for using 2carpros. Com.

The first thing I need you to do is check the front differential to make sure it isn't out of gear lube.

Where the front axles attach is the differential and not the transmission. I attached two pictures for you to see. The differential is internally lubricated with gear lube which is a very heavy oil. Since you have a leak, one of two things is happening. Either you are out of oil, which will damage internal bearings, or you will get really lucky and only need to replace a seal to stop the leak and then refill the differential.

As you will see on the attached pictures, there are several bearings in the differential as well as the extension housing, where the seal and axle come together. Any of them can be bad as a result of low fluid. However, I would first question the extension bearing closest to the seal that is leaking. It may have caused the seal to fail.

To check the fluid, there is a plug on the front cover of the differential. Remove the plug to check fluid level. The fluid level should be level with the bottom of the opening where you removed the plug. If it is low, refill it until it starts to leak from the inspection plug opening.

Here is the type of fluid the front differential requires:

Motorcraft SAE 75W-90 Premium 4x4 Front Axle Lubricant XY-75W90-TQL
Specification. WSP-M2C201-A

Note: As long as you get the 75w90 premium type, it doesn't have to be the Motorcraft brand. However, make sure it meets the specifications listed.

Feel free to let me know if you have other questions.

Take care,
Joe

Make sure the differential is full first. If it is and there are no leaks, then that doesn't sound like the problem. However, there are front hub bearings on each side near the wheels. When they go bad, you usually will hear a howling sound that changes pitch when turning and with speed. Please keep in mind, I'm not there, so I am basing this on symptoms that I haven't heard or components I haven't checked. However, my suggestions fit the description you provided.

Check those things and let me know what you find. Also, feel free to let me know if you have other questions.

Take care and let me know the results.

Joe

Then you really need to safely lift the front of the vehicle and turn the tires back and forth as well as check the axles for play to determine where the problem is coming from. It could be many different things dealing with the front components including wheel bearing, axle bearing, internal differential components. Did you confirm the differential fluid is full?

Welcome back,

That's good news. Okay, did you check for excessive play in the front wheels? For example, is there play when you shake the wheel left and right as well as up and down with the wheel off the ground?

If there is no play, check to make sure there isn't excessive play in the universal joints. Here is a link that shows how to check:

https://www.2carpros.com/articles/how-u-joints-work

https://www.2carpros.com/articles/how-to-remove-a-drive-shaft

Next, I need you to check and make sure the transfer case is full. The transfer case is mounted to the rear of the transmission and is what transfers power to both the front and rear wheels. On the rear of the transfer case you will see two bolts. One is a drain and the other one, which is higher, is the fill and check location. I attached a picture for you to help identify the component. Remove the fill/check bolt. The fluid level must be just below the fill plug. If nothing comes out, use something like a piece of wire as a dipstick and confirm the fluid level is full or at least close to full.

If you find there is no problem with the u-joints, the fluid is full in the differential and transfer case, there is no excessive play in the wheels resulting from a wheel bearing, then we will need to start focusing on opening up the front differential to check for bearing issues or evidence of metal shavings in the fluid as well as the transfer case.

I wish there was an easier answer. If you can, record the sound you hear and upload it for me. I may be able to identify it faster.

Take care and if I don't hear from you for awhile, have a great Christmas.

Joe

Honestly, I doubt it, but anything is possible. Are the tires worn unevenly?

Laurie:

If it is that bad, it should be aligned. Alignment, in and of itself, shouldn't cause the noises you described. But, it can lead to component wear due to excessive stress. What I suggest is to have it aligned. When it is being done, they will check all steering components prior to doing the work (at least they should). At the same time, ask them to check for any suspension or component that could cause the noise you hear. If the tires are bad enough, they could cause noise. Don't have anything replaced until you let me know what they are suggesting. That way, I can let you know if it is related.

Welcome back:

There are several bearings in the differential that can fail, although it isn't common. Interestingly, I had a Suburban with a similar issue today. It sounded really bad (grinding) but not all the time. The problem was a wheel hub bearing. As soon as I lifted the vehicle, the play was obvious in the wheel.

If possible, record the sound and upload it for me to hear.

Anything is possible. If you could upload the sound, I may be able to identify it easier.

Let me know.

Joe