Anyone have these go bad?

To make a long story short, had my front end apart this weekend to replace a CV axle (what a pain to pop that out) and a suspected wheel bearing. Had both sides apart, and both wheel bearings appear to be fine. Both sides felt smooth and spun freely once I removed the CV axle from the hub.


So, with the CV axles free of the bearings, I spun them and noticed some roughness. I can't tell if this is the issue however, but I noticed that they weren't exactly spinning in the differential smoothly. This however is impossible to describe over the internet just how they feel.

Symptoms are the classic "whirring" noise on the highway....although very faint. But also, the drivetrain feels rough at low speeds. I would suspect a wheel bearing here, but both fronts seem fine. I didn't check the rear though, as it feels rougher on braking. It also feels worse when it's hot, and is a little better when cooler (under 70 degrees)

I recently did front brakes as I thought the issue was grinding rotors. It was, but even with new rotors it still feels rough.

Going to jusr drive it for now, and see if it gets worse allowing me to more easily identify it. It's not that noticeable, except for me which hates any type of drivetrain noise.

If it is differential issues, i'm going to assume engine needs to come out to fix that? Looking through the FSM, it appears getting at those bearings (if they are even the cause) isn't going to be easy. And buying a used one off ebay ($300ish) might not be simple as I don't have the specialized tools to install the flanges and such.

http://www.nicoclub.com/FSM/G35/Seda..._Sedan/ffd.pdf

Guess its new car time. I'm starting to put more and more money into repairs as well as my time. It's actually the time that is influencing my choice to think about a new car. I would have rather been golfing this weekend vs working on the car (and not solving the issue)

 

Stupid question but have you checked the diff fluid? or ever changed it? Might be why you feel it more when it's hot and the oil is more viscous..

If you haven't changed your fluid lately, I'd suggest a high quality Redline 75W90 and see if it goes away.

I hate differentials and transmissions. Clearances/preloads/backlash etc, etc. Uhg. No thanks, I'll take it to a trans/diff shop.

According to the FSM you linked to, you can pull the diff w/o removing the engine, but sounds like a PITA...

Good luck!

 

Fluid was changed only 10K miles ago. Mobil 1 fluid. Level is fine as some did drip out when I replaced the front CV axle. I've run Mobil 1 since 50K miles.


Not quite 100% sure it's the differential yet. I *think* I notice the roughness is more noticeable during braking when the weight shifts to the front. So it COULD be still a wheel bearing.

Problem is, I can't tell which one. I took both sides apart and both bearings felt great when spun with the CV axles removed.

I'm just going to wait til the problem gets worse so I can more easily identify what the actual problem is

 

Just an update. Had the car loaded up this week for a road trip. The extra weight finally revealed the pass front wheel bearing is suspect. I'm relieved as a wheel bearing I can easily handle.

 

Glad to hear you have it figured out! So, what's your method for diagnosing a bad front wheel bearing? My car lately has been getting a bit louder up front, but how would I know if it's tire noise, or a bad bearing? I'm up to 103K, and as far as I know, the wheel bearings are still original (I bought it used with 64K).

 

Well, with previous failed bearings, I used to jack up both front wheels and remove the rotors and spin the hubs by hand. You could just feel the roughness in them.

However, this latest time, they felt smooth, even when I pulled the CV axle out to replace.


But, this weekend I had a couple hundred pounds of luggage, and 3 passengers and the car was heavy. You could feel when I braked, the noise/roughness increased. I tried some turns and you could tell it was rougher in one direction, vs the other.

Funny thing is car is now unloaded, and much quieter. using the same method, I can't tell what side it is again.

Pretty sure i'm going to replace my pass bearing soon. Already have the replacement bearing/hub ready to go.

 

Ah, thanks for the info! I will try it out. I have to replace the passenger side front axle (torn boot, grease everywhere but inside the boot LOL) and both compression rods, so since I will be in it that far, I may just bite the bullet and replace the hub/bearing assemblies too. I will check to make sure they feel rough or are making noise with the rotors off first though.