For those on board who have had to replace their front driveshaft, what symptoms did you experience? I've been having a low rotational "hum" that is most noticeable around 40MPH. It increases in velocity as I get to highway speeds and then I feel a vibration in the pedals and a bit in the steering wheel. Took it to a local shop a few weeks back and they thought vibration was coming from the transfer case. Took it to another local today and he thought it was drive shaft related but couldn't tell if front or rear shaft. I'm guessing its the front shaft and that's why the first shop thought it was the transfer case as that's where they heard the vibration with a scope. The second shop will charge only about $140 for the labor and I can get an aftermarket part for about $100 so not all that bad but was curious what others here experienced before and after replacement.

147 views and no replies?

Sounds more like a wheel bearing. Driveshafts vibrate when joints and such are bad but never really whine or hum.

Thanks for the reply.

I replaced both front wheel bearings with OEM hubs about 10K miles ago. If it were the bearings, I think the sound I'm hearing would change while turning at speed. Also, I don't think the bearings would create the vibration I get in the steering wheel and gas pedal at about 70 mph.

The fun part about diagnosing such noises is that anything that rotates could be the culprit

Barring any definitive answer, you could try to diagnose it yourself, as you've been doing so far. Pull the AWD fuse & drive the car in the same manner you normally do.

That move will promptly illuminate your AWD light on your gauge cluster, FYI. However, it also prevents the clutch in the transfer case from engaging the front prop shaft.
If the noises persist, then you can look at other components beyond the front prop shaft.

Also, I know you mention certain speeds. I'd suggest playing with the manual shifter to see if it is RPM related, being mistaken for speed.

Well I tried your suggestion of checking engine speed vs. speed of the car by using the manual shift feature and letting the RPMS run up to about 4.5k in first and second gear. No effect of the sound or vibration. The sound is most notable at about 40MPH and the vibes start about 70MPH. I'm not ruling out a wheel bearing although I replaced both of them a bit over a year ago.(Maybe I screwed something up or got a bad one - they were OEM from discountinfintiparts.com) It really feels like its coming from the front of the car and is driveline related. I'm also pretty sure its the left side from what I can hear. Since its much more noticeable now, I'm going to give the dealer a shot at diagnosing it on Monday. Hopefully its not an arm and a leg to repair. I'll post what I find out.

I got in a minor accident recently. My driver's side front wheel makes a low hum and vibration at 40+ mph now lol.

I jacked up my car, spun it, and wiggled it (RWD btw). Very little wiggle horizontally, no wiggle vertically. I feel friction on 1/4 of each rotation and can hear a difference during the friction part. I think in my case, it might be brakes/ calipers.

Did you get cheap bearings? I hear cheap ones can easily go bad in a year or 2

I'm having it looked over tomorrow. I'll update you with what the mechanic says lol.

I forgot, my hum is cyclic/ rotational. I don't notice a difference in sound when turning in either direction.

Ok so with how old and well loved my m35 is ('07 and 314k+), they suggested replacing inner, outer tie rod, and I think a bunch of other suspension things. They said it was making a bunch of noise so the list is the start of it.

https://forums.anandtech.com/threads/cy ... 5.2391717/
Did you check your balance/ alignment?
I'm not planning to align my car until I get 80% of my front suspension changed. Lower control arm prices are 🥴

My symptoms were a vibration and speed felt throught the floor. Also, when putting vehicle in gear and moving either forward or reverse I could hear and feel metal clank. Jacked car up enough to spin front wheels by hand and watch front u-joint and discovered the issue. Not too bad a job if you don't have to deal with rusted bolts like I had to.

Danyjon wrote: ↑

Sun Jul 05, 2020 10:24 pm

I got in a minor accident recently. My driver's side front wheel makes a low hum and vibration at 40+ mph now lol.

I jacked up my car, spun it, and wiggled it (RWD btw). Very little wiggle horizontally, no wiggle vertically. I feel friction on 1/4 of each rotation and can hear a difference during the friction part. I think in my case, it might be brakes/ calipers.

Did you get cheap bearings? I hear cheap ones can easily go bad in a year or 2

I'm having it looked over tomorrow. I'll update you with what the mechanic says lol.

No I got what were supposedly OEM bearings from discountinfintiparts.com. I believe its a dealership out of Texas that ships the parts. The service rep at the dealer thinks my issue is simply tires. I have Michelin Primacy MXM4's with about 38,000 miles on them. That's not a huge amount of wear for a 55K mile tire. They were on the car when I got it and still appear to have good tread but he said they were feathered and are 2MM on one side and close to 4 MM in the other side of each tire.

So......I'm getting a new set of Bridgestone installed on Thursday and then will get a 4 wheel alignment. I guess I'll hold judgment until the new tires on on the car, but I really think my issues are more driveline related. We'll see.