Whine noise while accelerating/cruising

[Afboy143]

Hey guys,
First I did a search but really didnt find anything. I did find the following thread

http://www.explorerforum.com/forums/showthread.php?t=157872

But this applied to newer explorers than mine.

My truck will make a whining noise when I accelerate and cruise- around 50 mph at 1800 RPMS. When I let off the gas, the whine goes away, but once I hit it again it comes back. I can also hear the truck "whine" or "wind" down when I brake or let the truck slow down on its own. Anyone have ideas what this could be and how easy a fix it is?

99' explorer with 120K miles, 4.0 SOHC 2WD

 

[vintagecar]

I was told it was a differential problem. worn gears, pinion, etc... Mine is doing the same thing.

 

[Afboy143]

I was told it was a differential problem. worn gears, pinion, etc... Mine is doing the same thing.

Well that sucks. Anyway to slow it or help fix the problem at all? Thicker oil or additive?

 

[slickknick]

Did you fix/replace the rear diff? Did it fix the problem? My 99 with 192,000+ miles whines like a baby also.

 

[ericautopart]

Sounds like a pinion bearing..I've got the kit..it's $72.40.

 

[slickknick]

How difficult is it to install?

 

[dean1997sport]

 

[Afboy143]

Honestly Ive been letting it go and its been fine. Just that noise- but Im used to it now. Ive got catless flowmasters so it drones it out a bit

 

[ericautopart]

If it's the pinion bearing..eventually it'll seize and wear away at your housing..causing you to need an entire new housing. What'll cost 70 bucks plus some labor now cause cost thousands down the road. It's not a repair you can read up on and do yourself, it needs to be done by a professional.

 

[alohamonte]

Well that sucks. Anyway to slow it or help fix the problem at all? Thicker oil or additive?

I have the same issue. I get rear end whine around 55-60 mph @ 2000 rpm but it's not noticeable above or below that narrow speed (mph) range. Doesnt sound like a metal on metal, more like at a certain speed theres a high pitched tuning fork like hum.

My gear oil is less than a year old. I guess I'll change it out just to be safe... I thought these axles were supposed to be bulletproof.

Manual says 75w-140 with LS additive. I've seen 85w-140. Think that would do anything? Or a different brand? Might be time crack open the wallet open for Royal Purple.

EDIT: Just crawled under the pumpkin, the plug looks like received a 1/2 inch drive. Does that sound right?

 

[96eb96]

EDIT: Just crawled under the pumpkin, the plug looks like received a 1/2 inch drive. Does that sound right?

Mine is 3/8" square. Just use a socket extension.

 

[alohamonte]

You are correct 3/8. I just took the plug out. Fluid looked clear. Magnet was clean. I hate these sort of problems...

 

[gijoecam]

My money would also be on a pinion bearing issue. The longer one waits with a differential problem, the more money it costs to repair it.

 

[Burnout]

Is it from the rear or the front?

On my '04 (which I'm pretty sure is the same gen as '99), the day I got it I heard a whining from under the hood when I accelerated or put on cruise, like you. Just before I got home the rpms started going up and it wasn't really accelerating. Turns out the torque converter seized up and the transmission had to be rebuilt (hurray for used warranties). If it's from the front, I would check on that because it would suck if that happened to you as well.

 

[Afboy143]

If it's the pinion bearing..eventually it'll seize and wear away at your housing..causing you to need an entire new housing. What'll cost 70 bucks plus some labor now cause cost thousands down the road. It's not a repair you can read up on and do yourself, it needs to be done by a professional.

Eric,
Say I were to call a shop to ask about getting this repair done, what exactly would I ask to get a quote on? "Whats the cost to get my pinion bearing replaced?"

 

[Afboy143]

Well I called a few places. They said the rear end needs to be rebuilt and Im better off getting a used rear end off another truck and putting it in ess. since my truck has 125k miles and isnt worth a lot. Looks like Im going to drive it until my rear end blows up-- then replace. WOOHOO

 

[Afboy143]

So does anyone have any tips here? Any fluid I can add to cut down on the noise? Any ideas?

 

[Afboy143]

Hey guys, bringing this back from the DEAD. Ericautopart- how do I go about purchasing this kit from you and when I contact a shop, what do I tell them exactly I need done to get a quote? "99 ford explorer pinion bearing kit installed?" What kind of shop is best suited for this? Transmission?

 

[storlied]

Driveline shops. Places that specialize in making/balancing driveshafts, replacing u-joints, axle bearings and so on.. they will do gears also.. but not for cheap...

 

[Afboy143]

Driveline shops. Places that specialize in making/balancing driveshafts, replacing u-joints, axle bearings and so on.. they will do gears also.. but not for cheap...

This is what I was afraid of. I found a rear end at a local junk yard with 60k miles on it for $300. Might as well pick that up and install it eh?