Life Expectancy of Rear Diff?

[maximilian99]

I've got an '03 Limited V6 4wd with 100,000 now. So far, all's fine. However, and it could be my imagination, I think I can hear a very very slight singing (high pitched sound) coming from something under the truck, when I'm coasting. Again, maybe it's just my imagination, or so slight, it's just noise that a 4wd would make all the time and I never really noticed (and no, it's not in 4wd when I hear it).

Having some experience with diffs and carriers going bad, I know that the first tip you get is a "singing" from under the car, usually while floating (not accelerating or decelerating). In tjos case, the sound seems to be when actually coasting, like up to a light or something.

Anyway.......at what point do you have to start thinking about serious maint. on the the stuff behind the transmission?

Thanks!

 

[PredBlue]

At what speed ranges are you hearing this?

 

[maximilian99]

At what speed ranges are you hearing this?

I think slower speeds, maybe 30 or less as I'm coasting up to a stoplight or sign. Above that it could be there, but I haven't noticed, and road noise could be drowning it out.

 

[PredBlue]

I think slower speeds, maybe 30 or less as I'm coasting up to a stoplight or sign. Above that it could be there, but I haven't noticed, and road noise could be drowning it out.

I've never heard it at that speed, but it seems like there have been several people noticing a very slight (you have to listen for it to hear it) whine in the 60-65ish range when coasting. I'm not saying it's "normal", but that seems to be a fairly common occurrence in the higher range. If you're hearing it at the lower speed, I'm not sure which direction to point you. Sorry.

My experience with multiple vehicles has been when there is a very slight whine in a particular range, it doesn't seem to be a significant issue, but when I've heard a whine over a broad speed range it seems to end up being a major issue. I think I could trace back all issues to "poor maintenance" so I'm going to assume that you've stuck to a regular maintenance schedule which should eliminate that possibility.

 

[alreadybeenused]

I have a '03 Limited V8 with 70,000 miles and haven't noticed anything with the rear differential but recently found out that I'd sometimes hear a high pitched sound (singing) while sitting at a stoplight. I realized it was coming from the fan for the ac/heating, even on a lower setting. It's very faint and intermittent. Perhaps it's that?

 

[tcpoob]

also see http://www.toyota-4runner.org/4th-gen-t4rs/61831-flying-saucer-noise-when-4runners-moving.html

 

[CJ3Flyr]

When was the last time the driveshaft was greased? Do you have a failing u-joint?
http://www.toyota-4runner.org/maintenance/28414-07-v8-4x4-zerk-fitting-pics.html


If it is the rear the sing I have heard them sing for 100k provided they get a steady diet of clean fluid.

 

[BassMiesterNJ]

My rear diff needed work at 60k 2007 Sport.

All fixed. Running like a champ. No explanation for problem.

(1) Carrier Assy, Dif - replaced
(1) Gasket, Dif - replaced
(6) Gear lube

Align four wheels.

New tires.

Feels like a new truck.

 

[Autbond]

I currently have 67k on my 06 Sport V8 4wd and havent heard anything.I wheel it pretty hard every week or 2 and I am running 33 inch mud grapplers. Some people strongly recommend the rear diff breather if you take it offroad at all. I did change the fluid in the front and rear diff's at about 55k though. I would definitely change the fluid in your diff's every 25k miles after 50k and buy royal purple fluid if you can. The more maintenance you do over time the less time and money you spend on repairs, that's my biggest tip.