Rear End Whining and I'm Confused

[rrbb_davis]

Just recently purchased and a 97 Explorer XLT. Any accerlating above 30mph causes a whining noise coming from rear end more specifically inside the pumpkin. IF I let of the gas the whining stops till I resume applying gas again.
I have read alot about the rear end problems the Explorers experience. I am confused as to what is the failure I have read that its the ring & pinion and I have seen others says its the differential.

This being my only vehicle I would like to order the parts and have them here before I tear it down and fix. Instead of tearing it down then ordering the parts. The dilema is do I need both the ring & pinion plus the differential or one or the other. I hate to pay for unneccessary parts. As common of a problem this appears to be was hoping someone could point me in the right direction.

Also, I have seen that people have fixed this problem only to have repeated failures. Is there a permant solution to the problem that will result in not having to repeat the same fix again.

Thank you all for you time.
Best Regards,
Ryan

 

[GETMYBELTSON]

If you want to do this yourself you should probably buy the pumpkin with the gears you want already installed. If you have a mechanic then you can just buy the ring and pinion. Installing the ring and pinion requires a little more attention to measurements than the average garage joe is used to. And if you are off, the gears will whine/howl.

 

[ericautopart]

If you want to do this yourself you should probably buy the pumpkin with the gears you want already installed. If you have a mechanic then you can just buy the ring and pinion. Installing the ring and pinion requires a little more attention to measurements than the average garage joe is used to. And if you are off, the gears will whine/howl.

x2 or worse bind and explode.

 

[my pos mounty]

IF I let of the gas the whining stops till I resume applying gas again.
I have read alot about the rear end problems the Explorers experience. I am confused as to what is the failure I have read that its the ring & pinion and I have seen others says its the differential.

The ring/pinion is part of your differential.
The driveshaft flange on the rear axle assembly is attached to the pinion shaft, that shaft in turn tuns the ring gear. The ring gear is pressed/bolted to a carrier.
Typically, the bearing around the pinion shaft is the culprit of the whine that you hear. Usually, the rear axle assembly would be "pissing" out diff oil around the pinion seal if this was the case.
Either way, it is usually a bearing issue and not a gear issue.

This being my only vehicle I would like to order the parts and have them here before I tear it down and fix. Instead of tearing it down then ordering the parts. The dilema is do I need both the ring & pinion plus the differential or one or the other.

That picture shows a differential. Ring gear being the large gear (towards the left), the pinion gear is not visible but is essentially the shaft that the rear driveshaft would attach to.
If you replace the ring gear or the pinion gear, then you MUST replace both, as they are a matched set. They wear on each other and replacing one will yield disastrous results eventually.
The carrier (holding the ring gear) has bearings that are under the "caps" on either side of the carrier. 2 Bolts per cap. Some times it is these bearings that are the source of the noise. If you take this apart to replace the bearings, those caps must go back in the same position and orientation. Read up on rebuilding the differential HERE. It requires tools that the "shadetree" mechanic usually will not have.

Also, I have seen that people have fixed this problem only to have repeated failures. Is there a permant solution to the problem that will result in not having to repeat the same fix again.

The semi-permanent solution is to have it professionally rebuilt. If done properly it will outlast the remaining life of your truck.

If you want to "roll the dice" on getting a replacement rear axle assembly, www.car-part.com is the best search engine that I have found for that purpose.
You will need to know your axle ratio, in the drivers door jamb, theres a sticker that looks like:

Whats circled in red is what you need. Your code may be different. List of codes:

Explorer
Door Code/open or limited slip/ratio
41....….…… Open 8.8"…...….. 3.27
42..…..……. Open 8.8".….…... 4.10
43..……..…. Open 8.8"…..…... 3.08
44..………... Open 8.8"….….... 3.73
45..…..……. Open 8.8".….…... 3.55
46..……..…. Open 8.8".…….... 3.73
D1..……..…. L/S 8.8".…...…... 3.27
D2...…..…… L/S 8.8".…...…... 4.10
D4...….……. L/S 8.8".…...…... 3.73
D5..……..…. L/S 8.8".……...... 3.55

If you replace the entire assembly, ensure the replacement is the same ratio.
If you want a "how to" on replacing the entire axle assembly, check HERE for a thread I wrote a while back.

 

[imp]

Generally speaking, whine or hum which is present only when accelerating or driving the vehicle at speed, NOT coasting with foot off the gas pedal, is caused by the ring and pinion gear teeth themselves.

However, the gears are not always at fault, as failed differential bearings or pinion bearings can allow misalignment of the gear teeth which produces whine. Usually, bearings in failure mode have already begun to grumble plenty before such misalignment occurs, alerting one to their condition.

In simpler terms, it is nigh onto impossible to order PARTS individually before inspecting those 4 bearings, as well as the differential gears themselves, all 4 of them, AND the ring and pinion gear teeth as well.

You cannot replace ONLY a ring gear, OR pinion gear; they are matched sets which are lapped together during final manufacture. imp