Explorer rear end -- pinion gear replacement??

Sure it's the rear? The front hubs do that a lot. Oh wait, if you don't have a solid rear axle, it could be a rear hub. Do you know what's under the rear?

CJB

I would expect (suspect) a bearing before the ring & pinion gears. R & P gears generally last the life of the vehicle. Lots of people will buy used R & P gears sets (used differentials) at a junk yard and use them in other cars or trucks for many more years and several tens of thousands of miles.

THis is true, R&P's can last a very long time if they are serviced from time to time but many neglect to change the lube in them even once which can shorten the lifespan of a a rear drive axle. It is even more important to change fluid in them if you tow of use them in severe duty cycles too. Generally speaking rear axles are not as generous in size and reserve capacity as they were 20 to 30 years ago in light trucks so this makes maintaining them more important.

----------------- TheSnoMan.com

There are three of those 2002-2004 Explorers in my immediate family. The rear wheel hub assemblies have gone out in all three. One, my sisters, has had three replacements. No ring and pinion trouble in any of them. The rear wheel hub assembly can cause your symptoms.

Spdloader

Did you read the original post? The vehicle we are talking about is an '04 Explorer with 70k miles. It is just now reaching the point where differential service might be due for the first time.

It may help to change the oil, but my bet is still on a bearing. I'll even suggest a wheel bearing as opposed to a bearing in the diff. And, the tires can be making noise too, that can be diagnosed as an axle problem.

Before the diff gets torn apart, there are far too many other things that can cause noise -- and the R & P gears are way down the list of Usual Suspects.

I read post. Oil/lube should have been changed LONG before 70K regardless of what manual says. Every 20 to 30K is more reasonable. Generally you see a lot more rear end problem today than 20 or 30 years ago because like I said less reserve capacity in some of them and extened change intervals to make it lot more attractive to buy and maintain. When I get a new truck, I change fluid in rear axle after about 1000 to 1500 miles or breakin and BEFORE i tow with it. Drive axle are often neclected for servicing and now usually use lighter lube in them which has less tolerance for grit in it because film is thinner.

----------------- TheSnoMan.com

Don't you come to a full stop before selecting 4WD too?

If the bearing on the pinion shaft has been bad for a while, and if there is play, then the pinion depth will be off, the mesh of the ring and pinion will be off, and a bad wear pattern set. Once that happens, its gear time. On the other hand it will run like that damn near for ever if the lube is changed regularly, like every 24K miles. Has the input shaft seal ie the pinion seal ever been changed? Have seen cases with meat head uses impact gun to tighten pinion nut insttead of torque wrench, over tightening causing the crush sleeve to crush too much resulting in bad gear mesh which again causes a bad wear pattern, noise etc andrequires gear replacement to correct. Does the noise abate somewhat when the throttle is let off, for that few seconds between accelerating/deaccelerating?

Whitelightning

LMAO When you get a new truck? Snowblower you are funny. The last new truck you got was a 1964 Chevy half-ton that you promptly put way too low rear gears in. What the hell do you know about modern ('90 model year and newer) rear end duty/service cycles?

Modern rear ends with modern lubrication do not need there lubrication changed at 20k-30k miles. Wait, don't tell us, you change your brake fluid every 6 months too, right? Come on snowblower the man wants help diagnosing the noise he is having, we don't want to listen to your off topic BS about excessive maintenance.

My guess is that an '04 Explorer with 70k miles has not had the diff rebuilt.

Yes, IF the bearing (more than one, actually) on the pinion shaft has worn, there could be gear wear. At 70k miles, I would not expect that to have happened yet, but that's a possibility.

That's what it sounded like to me too. those have IRS then?

Yep , sure do.

If that's the case, then much/ most of what was posted above concerning the workings of the solid rear axle don't even apply, right?

CJB

Well, the ring and pinion stuff still technically applies, but normally isn't the culprit at such mileage unless there is a defect.

Spdloader

The real problem istrying to diagnoisa noise we cant hear. The noise gears make is very different than the noise a "hub" bearing is going to make. and off course one I didnt mention and havent seen mentioned is does the noise change making turns? The pinionbearings and the ringand pinion gear are not going to change rpm in a turn, but the hub bearings or axle bearing on a solid axle will, and pitch will change noticably. Of course its been my experiance that gears whine and howl, and bearings usually rumble, and grind. It really doesnt take that long to mess up a set of gears if they arent right clearance wise. Anyone thast has set them up the old fashioned way using white lead(now I am dating myself) knows this.

Whitelightning

Quote:

"The real problem is trying to diagnose noise we cant hear. The noise gears make...."

Amen to that.

Spdloader