I don't honestly know. I just know that I have read a number of posts here and over in F-150 land (which shares the same basic front end) about issues with the vacuum hub actuators causing a variety of symptoms. It might not even be that one is partially failing (that classincally gives a grinding sound in 2WD that goes away in AWD and 4H). It could be one engageing that the other not....

Just thinking out load here -- I wonder if having one side engaged and one side not engaged would cause a vibration sort of feeling -- what would happen is that the diff would turn, even in 2wd, and the axels would be rotating in oposite directions. Just thinking, not sure if that would cause your phenomenon.

Vibrations of course occur with bad CV joints all the time. Have you considered replacing it? Especially seems fishy that you get the vibration or noise only when turning to the left.

Does it do this in 2WD, AWD and 4H all three?

If you are close to KC, I would GIVE you a used CV joint that I pulled when I went through my front end. They were not bad, to the best of my knowledge, but I picked up NEW once for about $60 (really!) each and decided while I had the whole front end apart, why not go new. The work of getting to the CV to replace it is the bigger issue.... I kept the old ones, as throwing away decent parts seemed strange...

Well, good luck. And whatever you do, please post back what the final outcome it....

 

[QUOTE=cdherman;11490791]I don't honestly know. I just know that I have read a number of posts here and over in F-150 land (which shares the same basic front end) about issues with the vacuum hub actuators causing a variety of symptoms. It might not even be that one is partially failing (that classincally gives a grinding sound in 2WD that goes away in AWD and 4H). It could be one engageing that the other not....

Just thinking out load here -- I wonder if having one side engaged and one side not engaged would cause a vibration sort of feeling -- what would happen is that the diff would turn, even in 2wd, and the axels would be rotating in oposite directions. Just thinking, not sure if that would cause your phenomenon.

Vibrations of course occur with bad CV joints all the time. Have you considered replacing it? Especially seems fishy that you get the vibration or noise only when turning to the left.

Does it do this in 2WD, AWD and 4H all three?

If you are close to KC, I would GIVE you a used CV joint that I pulled when I went through my front end. They were not bad, to the best of my knowledge, but I picked up NEW once for about $60 (really!) each and decided while I had the whole front end apart, why not go new. The work of getting to the CV to replace it is the bigger issue.... I kept the old ones, as throwing away decent parts seemed strange...

Well, good luck. And whatever you do, please post back what the final outcome it....[/QUOTe
I did replace the CV the same time I did the hub. I also get the noise regardless of the 4wheel setting. I'll keep you posted as to the outcome.