1995 Camaro v6 3.4L


I've been trying to find the cause of the humming/howling noice coming from my rear end. I initially thought it was a wheel bearing so I changed it out and it wasn't.

I just dropped my driveshaft and one of the ujoints has a LOT of friction in the directions shown in the pic below. The ujoint on the tranny side moves freely like I would expect, but the ujoint on the differential side has quite a bit of snag -- by hand you can barely turn it in the direction shown below.

Would this cause a humming/howling sound from the rear end?

Thanks,
kisk

 

Are there grease fittings? If there are, give it a good shot of grease. Someone else will time in I hope.

 

In most cases U joints do not cause humming noises, that is a function of wheel bearings, rear end gears, center baring in two piece drive shafts,bad wheel bearings,or even damaged transmission gears. A stiff U joint like yous will eventually break down and start making clanking noises and eventually break. As musicman said, try to grease it, or if that is not possible,replace it.

 

it is a 2-section driveshaft. someone from another forum suggested that while I have the DS dropped it would probably be a good idea to hit the salvage yard and pickup a one-piece DS. What are the perks of this and how could this help me in the long run? What year models should I be looking for when pulling a DS from a yard?

I know my problem is not the rear bearings near the wheel hubs as I just replaced them and it made no difference. Its weird because the humming/howling seems to be coming from the right rear axle (this is why I replaced those bearings in the first place). One of my guys up at Advanced said I would definitely hear when my ujoint was going out, but I was under the impression that I would hear clanks/clunks/clicks, not humming/howling.

And yes, there are grease fittings on each ujoint (kind of looks like the top end of a spark plug?). I'm going to replace the ujoint anyway... I'll get the shop to shoot up the tranny end ujoint.

Thoughts?


EDIT:
PS. Is this the grease fitting?

 

Let me also add that the humming/howling sound only occurs when the car is driven... when the rear is jacked up and rear wheels are running in 5th gear there isn't any of these sounds.

Ideas?

PS. I'm an automotive amateur so bare with me here

 

Yes, that is the grease fitting. I think my spelling is wrong, but that is a zirk fitting. Just go to wally world and grab a grease gun in the auto section and a tube of grease. It's really good to grease those fitting periodically. Even if your getting new u-joints, get the gun anyway. There are more fittings you can grease. I live on a farm that runs a heck of a hay operation in the summer, and grease keeps everything going.

 

Pete is right about what he said, u-joints don't hum. Check the bearing on the other side while your this far in, and when you put them in, make sure you grease the heck out of them. I have a bearing packer, but if you don't have one, put a big glob of grease in your hand and smash the grease into the rollers. It take a rolling motion too. You know you have enough when the grease comes out the other side. This takes a while, and you'll be surprised at how much grease those bearings hold. If you put them in right out of the box, they will not last long at all. Just making sure everything is getting done right. To me it sounds like a bearing problem, check em all if you can.

 

Adding all-purpose grease to the bearings won't mess with the differential fluid (80w), right? Remember, amateur here

I'm hoping for the life of me that its not the axle bearings in the differential housing as I have no clue how I would pull them. After pulling all my diff gears out(A1/A2/B1/B2) and the 2-screw clamps (C1/C2) that sit against the bearings, I'm not sure how I'm supposed to get the actual bearings out. Do I have to drop the entire rear end to be able to pull out those bearings?

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Also, just to clarify the terminology, what I have labeled in the image as "is this the "ring" -- that is the ring correct?, and it is spun by the pinion, which is spun by the driveshaft/u-joint. Is this right??



Thanks again everybody for helping

 

Another thing to consider, just because this happened to me, I had similar sounds coming out from under my car at speeds between 0-20 and it was horrible i couldnt figure out what it was but while it was up on the hoist we ran it slowly and had to actually run it alot faster prolly about 80 mph to hear the sound and we found out it was the Hanger bearing within the drive shaft, I don't know an extreme amount about driveshafts/rear ends but we ended up just relubing the hanger bearing cause GM in our town said it would cost about 800 bucks for a new one cause you can't replace them. But so far its been quiet like before so maybe you just need to lube some stuff up sometimes with those new car washes that spray the under side of your car you get moisture in areas like that and it washes off grease that stops rubbing, just a thought !