Front end diff bearing whirring

[Davy-Crockettm28]

I noticed a whirring noise coming from the front end while driving on the highway. It is most noticeable around 60-70 miles per hour, but it's still rather subtle. It sounds like the stereotypical whine of a supercharger and lets off when you take your foot off the accelerator. I believe this is the differential bearing on the front diff because the noise comes from the front, and both the front and rear diffs are slowly weeping oil (My dad doesn't think it's worth it to replace the seals).

Do you all think my assessment is right that it's the Diff bearing, and if so, what would be a reasonable price range to expect when we get it replaced? Our old transmission shop at one point quoted us a few grand for the seals because they didn't know what else they would find (we don't do business with them anymore because of declining service quality and bad repairs on one of our other vehicles)

Any advice on how to proceed or ideas on other things that would be worth checking are greatly appreciated

 

[JKP]

Drop the front driveshaft out and see if it goes away. It's more likely to be the double cardan in the front shaft.

There's no issue driving it without the front shaft.

 

[Davy-Crockettm28]

By double carden, I assume you mean the front drive shaft. If it is the shaft would it be more effective to just replace the whole thing, or is there a specific part to replace (its got slightly over 200k miles on it so it probably wouldn't hurt to replace the entire thing)

 

[JKP]

There's one u joint by the diff and the double cardan is at the transfer case. At that mileage you would replace both. You would also need to check the slip joint for slop.

A new front DS cost me about $470 last year.

But it's free to pull the DS and see if the noise goes away.

If the noise turns into what is called angry sparrows at low speeds, you don't want to continue driving it as it will destroy the transfer case if the double cardan seizes.

 

[Davy-Crockettm28]

Next week, I should get a chance to take it off and see if that's the cause. If I do need to replace it do you have any recommendations brands or websites to look at avoid?

Also, how do I check the slip yoke for slop?

Thank you

 

[JKP]

I went with a Tom Woods shaft.

The front DS is two pieces that slide in and out of each other. If worn, there will be slop in this splined joint.

 

[AndyG]

I’d move fast if you drive it daily. A front shaft lock up ain’t good. At all. Also if it’s pinion related you might mitigate some damage but who knows.

 

[Davy-Crockettm28]

I’d move fast if you drive it daily. A front shaft lock up ain’t good. At all. Also if it’s pinion related you might mitigate some damage but who knows.

Will do, I think Ill get a chance this week too test it, and next week I should be getting paid so I can order a replacement. If it does wind up being the driveshaft, I assume I should just leave it off the vehicle until I get the replacement?

 

[JKP]

Yes. No issues driving around without it for as long as you need to .

If it's just the u joints, they can be replaced for somewhat less than a new DS.

 

[BlueC]

Our old transmission shop at one point quoted us a few grand for the seals because they didn't know what else they would find (we don't do business with them anymore because of declining service quality and bad repairs on one of our other vehicles)

If your location info is accurate, I have transmission shop recommendations for you if you're interested.

Will do, I think Ill get a chance this week too test it, and next week I should be getting paid so I can order a replacement. If it does wind up being the driveshaft, I assume I should just leave it off the vehicle until I get the replacement?

Yes, if that makes the noise go away, I'd leave it off. If it turns out to be one or more of the joints, it can be rebuilt pretty easily, assuming everything else in the shaft is fine.

 

[Gilaguy23]

A few grand to do the seals They should be doing a full on regear and rebuild for 3K.

 

[Davy-Crockettm28]

Oh I didn't think about that. If i just replace the U joints

If your location info is accurate, I have transmission shop recommendations for you if you're interested.



Yes, if that makes the noise go away, I'd leave it off. If it turns out to be one or more of the joints, it can be rebuilt pretty easily, assuming everything else in the shaft is fine.

I would greatly appreciate a recommendation for a transmission shop. My sister's WJ is gonna need a trans rebuild sometime soon. We've been going to LNR transmission in Winston for a while, but recently their customer service and work quality has significantly decreased

If it winds up being the shaft, I'll likely replace all the U joints ( double Carden joints and front joint) so that I can knock them all out at once. Aside from the joints and straps, is there anything else I should replace on the driveshaft?

 

[Davy-Crockettm28]

A few grand to do the seals They should be doing a full on regear and rebuild for 3K.

That's kind of what we thought. Additionally, when my buddy and I had to replace the transmission fluid (whole story thats too long for here), we found that they had left an indentation from a pry bar on the transmission pan (right where the gasket sits) and had used a super thin quark gasket rather than a rubber gasket

 

[JKP]

There is a rubber boot over the slip joint that you should check.

 

[Davy-Crockettm28]

There is a rubber boot over the slip joint that you should check.

What should I look for when I inspect the slip joint? And is there a way I can visually or physically inspect the U-joints while Im under there? I still plan on removing the drive shaft to actually test it

 

[BlueC]

We've been going to LNR transmission in Winston for a while, but recently their customer service and work quality has significantly decreased

Well, that was going to be one of my recs. I had a trans rebuilt by them in '20 and they did a good job. They took a while to get it done, like 5-6 weeks, but they came highly recommended by a few mechanic friends. I had no complaints, but I haven't used them since. The other shop I recommend is Friendly Transmission in Thomasville/High Point https://www.friendlytransmission.com/

 

[BlueC]

What should I look for when I inspect the slip joint?

Make sure it moves. If you pull it apart, make sure you have an alignment mark (sharpie works) on both sides so you know how/where it goes back together.

 

[JKP]

What should I look for when I inspect the slip joint? And is there a way I can visually or physically inspect the U-joints while Im under there? I still plan on removing the drive shaft to actually test it

You're looking for looseness in the joint.

 

[JKP]

Make sure it moves. If you pull it apart, make sure you have an alignment mark (sharpie works) on both sides so you know how/where it goes back together.

The front and rear shafts on my 06 were keyed. I was pleasantly surprised.

 

[Davy-Crockettm28]

Well, that was going to be one of my recs. I had a trans rebuilt by them in '20 and they did a good job. They took a while to get it done, like 5-6 weeks, but they came highly recommended by a few mechanic friends. I had no complaints, but I haven't used them since. The other shop I recommend is Friendly Transmission in Thomasville/High Point https://www.friendlytransmission.com/

My dad has been doing business with them for a while and was always happy with the service until recently after some bad experiences with them