I'm getting some rythmic humming at about 112km/h....starts at about 100km/h but is most noticable and loud at 112km/h and then gets less noticable as I go past 112km/h but is still there to some extent. Already ruled out front driveshaft by removing it. Have slight bearing play in passenger side front unit bearing...it's not much, but would it cause this rythmic humming or should I be looking elsewhere? Thanks for any info.

01Turbo

 

Check any antenna's you have mounted for resonant vibration. It's pretty visible as a mechanical standing wave.

 

Do you have nothing better to do than jerk people around?

 

Drive past the hum @ 120 kph and put it in neutral. As you coast to 100 kph do you still have the vibes? If so, check driveshaft and u-joints for play. If none, check output shaft for excessive movement.

 

Have you recently had an alignment done? Too much caster will cause this starting from about 60mph/100kmh. I have firsthand experience with it.

 

Two piece driveshaft? I had that when my carrier bearing or center bearing as some folks call it started to wear out on the rear driveshaft.

Could also be a tire. Check the sidewalls for a slight indent or bump. A friend of mine that worked at a tire shop for many years pointed that one out to me.
I did not feel anything from the tire with the indented sidewall but it would make a slight droning sound. When I rotated, I took that one out and one of my spares.

Actually an antenna can do this...so can a mirror, door handle wipers, grill etc...catch the right amount of wind and things can buzz.

 

No, one piece rear driveshaft. Also ruled out front driveshaft by removing it. Don't think it's a tire issue as the sound gets more or less intense as the load on the front end changes and the fact that I have noticeable play in the bearing when I grab the tire at the top and bottom and push-pull. As for antennas etc...no, definitely not...I would think that most people can tell when they are having noises indicating a mechanical failure in progress...also, I am now getting some noticeable vibration that I can feel thru the steering wheel and the seat of my pants accompanying this rythmic humming and droning sound which has gotten louder. Oh well, I picked up a new hub and will attempt to replace myself...not looking forward to it as the horror stories on here about this job almost make it look like it's better to have a dealer or independant shop do it, but that's not in the budget right now.

01Turbo

 

Don't fear the hub replacement......it's not hard at all!!!! Just take your time and have some patience. Also, a large 3-jaw puller helps with this as well.

 

I did not have the humming, but a very faint vibration that never ever really went away. Only happend at 100 km/h and above. Ended up needing the rear drive shaft balanced. Now she rides like new.

 

Ah...ya right. Took 4 hours of sheer hell to remove the hub from the knuckle and then from the outer axle shaft. My advice to anyone thinking about doing it themselves...if you live in areas of North America that have cold winters with snow and ice or you live in rust belt areas, it's worth paying a shop to do the job. If you live in rust free areas like Arizona...go for it, shouldn't be a problem. But anyways, I got it done and guess what?...The sound and vibration was NOT caused by this hub so I'm still searching for the culprit. Oh I just love mystery noises that you can't track down. Getting new tires tomorrow because I need them anyway, so we'll see if it was a tire balance or other tire problem...fingers crossed as this is getting very frustrating.

01Turbo

 

Ah...ya right. Took 4 hours of sheer hell to remove the hub from the knuckle and then from the outer axle shaft.


Well, in all fairness, I did say to have some patience . Sorry it gave you so much trouble and it didn't fix the problem.

 

Well, NOT the tires either. So, now I've ruled out the front driveshaft, the front hub bearings, the tires and replaced a bad u-joint in the rear driveshaft(diff end). Replacing the bad u-joint did make the vibration and humming/droning less pronounced, but did not cure it completey. I give up...I'm just going to wait for the evidence of where the problem is to get more noticeable and hope that whatever it is will not massively fail before that. I'm starting to wonder if it's a rear pinion bearing going bad or if the rear driveshaft somehow got out of balance. Will probably have the rear driveshaft checked for balance when I have time, but I'm not going to rip the rear diff apart until I know for sure that is the problem.

01Turbo