Topic: whinning sound, (not about mpg's)

[jcguin]

My 97 is developing a speed/load dependent loud whinning sound in the drive-train.

The frequency increases with speed, and disappears when you engage the clutch and almost completely when you let off the gas.  When you are going downhill and let off the gas it will make a transitional sound that is different until the gas is completely let off.

It does not really matter if you are in 2h or 4h, although it does sound a bit different (tonal).

Took it by a local tranny shop, he lifted it up and said it sounded like it was coming from the rear diff.  He then said it would be 600 in labor and probably a couple hundred in parts depending on the cause.  He said a pin or roller could be pitted and cavitating.  He then said he had an astro van that had a similar sound, but he has put 100k miles on it and it has not failed yet.  He wasnt garanteeing it, but at the moment it was a matter of money and nuisance value.  I could drive it till it broke or drove me nuts.  

All the fluid levels are good, so that is not it.

Anyone have any suggestions or similar symptoms.  I dont know enough about the shop to say I trust him, but others around me do.

[Jeffy]

I'd jack it up and see where the bad bearing is.  If it's an ourter bearing it will be easy to change out yourself.  Even if it's a carrier bearing, you could have change it youself.  Pull the carrier out then have someone press off the bearing and pres on the new one.  New bearing should only be around $10.  Removing and replacing the bearing shouldn't cost more then $20.

[jcguin]

I'm thinking it cant possibly be an outer,,,, every outer bearing I have had fail has had serious tonal changes depending on lateral g's.  Would the carrier be isolated from the lateral forces by the outer?  How would load/clutch effect it?

Also, I tried the 2h - 4h shift again this morning and the difference was much more pronounced, did not completely remove it but did effect it, no question.

The way the guy at the tranny shop checked it other than driving it was to jack up all fours and have a guy run it in 4th while he listened with a sort of stethescope underneath.  I got the impression that he isolated it to the pumpkin region.

Thanks Jeffy.

[jcguin]

Got fed up with it, the spyder gears were badly worn (abuse from previous owner), backlash on the pinion and ring were really off.  I just replaced the whole rear cause it was easier than trying to take apart the pinion and getting the backlash set right on my own.  Sound's great again, and the process wasnt too bad.  BTW:  the sound was coming from the rear pinion bearing and the transitional sound from the backlash.

[Dangerros]

I'm experiencing the same thing how much was the new rear end you replaced with?? I've been driving mines for 3 years with that whining noise kept on thinking it was the tranny.

[jcguin]

I paid 650 for the rear, plus I talked him into throwing  in a few other items I needed.  Wiper motor linkage, 4.0 tb w/sensors, rear shocks, springs, arms(his looked to be in much better condition than mine was)

[Gr8Ride]

Hey - just ran across your thread.  I have a '97 as well and as of about 4 days ago, I began noticing a whine.  It has progressively gotten worse.  Like yours, it only occurs when under a load.  When I mash the clutch, the sound disappears.  Although there's not really any noticeable difference in 4wd or not, there is a transitional sound when I let off.  Took the rear cover off and other than a very bad burnt smell, no serious markings on any gears and no slack to speak of (backlash out of whack).  Front, rear, trans and xfer case all full and clean.  Don't want it to get any worse but can't isolate either.  Thinking it's the trans because if it was any other contiuously moving part (bearing, u-joint), it would make the noise whether in gear, under a load or not.  Trans shifts fine though??!!  Just wanted to bounce this off you even though yours is fixed - just didn't want to believe it was the rear in mine...crap!

[Jesse-James]

Thinking it's the trans because if it was any other contiuously moving part (bearing, u-joint), it would make the noise whether in gear, under a load or not. 

Not true, I've had a pinion bearing go in my old Dodge P/U and had the same type of effect as jcguin. From what I understand most problems with the diff (other than broken gears) are only present while under load. I also had a bad rear DS Ujoint that was almost invisible unless under a load. Better the rear than the trans IMO.

[Gr8Ride]

Well, didn't intend to hijack this thread but am in dire need.  So I've been hearing a grumbling from my dana 35c rear the last couple of days so I pulled the cover.  Actually, like I mentioned earlier it is a howling when I'm on the gas and nothing when I'm in neutral or coasting...but a galling sound when I'm just between coasting and load.  Anyway, the spider gears are shot and very sloppy.  The R&P look fine and I don't have any fluid leaking from my pinion seal and there appears to be no play there.  I'm afraid to drive it without replacing the spider gears but it's THU and I can't get any in from a retailer until next week.  Does anyone have any for this "C"clip POS from a previous upgrade they'd be willing to sell and ship to me ASAP?  Good candidate for a locker or other upgrade but simply can't affort it right now.  Hope to hear from somebody soon - have also posted on the garage sale forum to hopefully reach a broader audience (my apologies if this is incorrect procedure).  Location: Waldorf, MD - 20603.
Thanks,
-Phil