CV axle slow death symptoms?

[BK_89iX]

I need some help tracking down a subtle "rumbling" that seems to be coming from the right front. It started about a year ago and very gradually it has gotten louder. It's most apparent at about 20-30mph, but it is present at all speeds, loads, etc. Vehicle is a '97 Explorer AWD SOHC with about 90k miles.

Here are some of the steps I've taken:

- Spent many hours here with the search button.

- Tires are pretty worn, so I swapped them front to rear. No change.

- Changed out the transfer case fluid. Nothing unusual noted.

- The noise seemed to diminish turning right or left at 40-50mph, so I suspected the wheel bearing/hub. Swapped both sides out for new ones yesterday, but unfortunately no improvement.

- While I was in there, I took a good look at the pads/rotors/calipers. That all looks good.

- I also had a good look at the half-shafts. All the CV boots are intact. However, on the right side, the CV shaft felt a bit notchy or unsmooth when I rotated it by hand. The left side felt very smooth by comparison, but of course it also rotates the front driveshaft, so maybe it's an unfair comparison due to the increased force/load required to rotate this side by hand.

So here is the question, am I on to something with the "feel" of the right CV shaft? Could this be the source of my noises? Are CV joints known to fail if the boots are still intact? There are no traditional symptoms like clicking or popping or something happening when pulling away from a stop and turning left or right.

Anything else I should be looking at before I throw more parts at it?

Thanks!

BK

 

[Hokie]

Unfortunately.... welcome to the club

http://www.explorerforum.com/forums/showthread.php?t=195466&highlight=problem

http://www.explorerforum.com/forums/showthread.php?t=210796&highlight=bearing

 

[mrgrumpynj]

I have something similar with mine, every once in awhile i get a bad vibration when the trans upshifts. Feels like im going over a rumble strips for 1 to 2 seconds. Ive lifted the front end and twisted, pulled and pushed on everything I could put my mits on, nothing seems loose. Does not happen all the time, so getting it to happen with a mechanic in the truck is near impossible. Hoping someone here may have a idea.

Don

 

[BK_89iX]

Thanks for the info, Hokie. I'm now less inclined to try and chase this one down. I already have new tires/balljoints/pads planned, so I'll see where things stand after those jobs.

Your symptoms sound different, Don. Mine is not really a vibration, but rather a non-metallic scraping/grinding/oscillating type of thing with the vehicle rolling. It's distinct at low speeds, and just "road noise" at freeway speeds.

BK

 

[E-rock]

if it sounds like scraping check the rotors, pads, and wheel bearings. cv axles make more a knock/tick/click sound. if that makes any sense.

 

[dontdrinkanddrum]

i have a '99 AWD SOHC and i've noticed some sounds coming from under the truck, most noticeably when I let off the gas and coast. I put the front end up on jacks and turned the front driveshaft, and found out that the CV joint on the rear of the front DS was binding up and needed replacing. have you tried anything along those lines? The way mine was sounding didn't seem quite like you described your sound, mine was more like an erratic grinding/ popping sound, but I figure it's worth a shot.

 

[BK_89iX]

i have a '99 AWD SOHC and i've noticed some sounds coming from under the truck, most noticeably when I let off the gas and coast. I put the front end up on jacks and turned the front driveshaft, and found out that the CV joint on the rear of the front DS was binding up and needed replacing. have you tried anything along those lines? The way mine was sounding didn't seem quite like you described your sound, mine was more like an erratic grinding/ popping sound, but I figure it's worth a shot.

I still need to try that. When I replaced the transfer case fluid I tried to inspect the front driveshaft CV boot at the t-case side - seemed to be intact and no evidence of grease sling. I'm going to have the front end up soon to do the brakes, so I'll try and check it out more carefully then. Thanks for the heads-up! Was your DS binding pretty obvious? I do have a bit of extra audible on gas let-off.

BK

 

[dontdrinkanddrum]

oh yeah, when I tried turning the DS with the front end up it would turn really easy for a bit, then it would get caught up and I'd have to force it to turn. what really led me to believe that it might have been the CV was the fact that when i heard the noise, it was a very audible and crisp sound, not like it would be if it was coming from something inside a steel shell immersed in fluid.

The boot on my CV was fully intact, though, and it still was bad, so just because the boot is intact doesn't necessarily mean it's good. Apparently this has become a big issue, the rear end of the front DS used to be a much better Double cardan design, but they switched to the CV design and people have apparently had lots of problems with them going bad.....what's more, I did some research and apparently the CV isn't serviceable, so the whole shaft has to be replaced. I'm planning on getting a 4" superlift this summer, so i'm gonna buy their aftermarket DS rather than getting a remanufactured OEM one

 

[BK_89iX]

oh yeah, when I tried turning the DS with the front end up it would turn really easy for a bit, then it would get caught up and I'd have to force it to turn. what really led me to believe that it might have been the CV was the fact that when i heard the noise, it was a very audible and crisp sound, not like it would be if it was coming from something inside a steel shell immersed in fluid.

The boot on my CV was fully intact, though, and it still was bad, so just because the boot is intact doesn't necessarily mean it's good. Apparently this has become a big issue, the rear end of the front DS used to be a much better Double cardan design, but they switched to the CV design and people have apparently had lots of problems with them going bad.....what's more, I did some research and apparently the CV isn't serviceable, so the whole shaft has to be replaced. I'm planning on getting a 4" superlift this summer, so i'm gonna buy their aftermarket DS rather than getting a remanufactured OEM one

Just a quick follow-up. I put the front end up and the front shaft turned pretty easily and smoothly. No obvious signs of an issue so I'm not in a real hurry to replace the part. A bit of axial play from the TC end, but nothing too crazy. I'll keep it on my list of suspects and I'll probably remove it for a road test....after I do the balljoints/alignment/new tires dance

BK

 

[dontdrinkanddrum]

yeah, i just bought a camber kit, so i'm probably gonna be going down that road shortly...good excuse to eat pizza and drink beer for a weekend, too busy fixin the truck to cook.