Rear differential noise

[justin0469]

When driving at highway speeds, I can hear a light humming of the rear differential (I am assuming), is that normal? It could very well be, it doesn't sound bad necessarily, I can just hear it.

[BlueCrush]

You just got a 2003 w/77,000 miles on it. Do you know if the differential has ever been serviced?Is it a high or low pitched humming?

[justin0469]

I don't...I asked for a service record on the vehicle when I first got there but by the time we were all finished, I forgot to pick it up. It is not like screeching or grinding, so I guess low pitched.

[ColonelPanic]

That could be bad. Say, it's not a Neptune, is it? Maybe you got Drunken's old one, as he was having some noise coming from the back when he traded. j/k! I don't think he had nav so you're probably ok there. But anyway, yep, BlueCrush is correct. See if the rear differential has been serviced, if not do it ASAP. It's what, 60K intervals, BlueCrush? 17K above isn't great but at least it isn't 50K. It could end up being something like the tires too, maybe even a wheel bearing. No telling.Good luck, justin!

[justin0469]

Well, how much does that usually cost? If it is in the service record that it was serviced when they received it as a trade in, then what?It is Neptune, actually. Don't scare me like that!

[ColonelPanic]

Oh don't worry, it would have had to go a looong way to get from IL to CA. I don't think he had the nav system either. Even if it was, be thankful you didn't end up with the Neptune FWD I traded in, you'd have a lot more to worry about than the rear end. hehehe!Not sure what the service costs though... Probably not much. If it's the rear end all together, a couple grand to replace it.

[justin0469]

Is "probably not much" relative to the complete rear end costing a couple grand? haha If servicing the differential just means draining the fluid and refilling it, I can do that (if warranty allows). While I'm down there, might do the auto tranny fluid too.Now you are scaring me that all Vibe owners trade in their Vibes because something is wrong with it!Edit: I was bored and went out to check things more intimately and found every fluid looked like it was just filled. Clean and to the top of the fill mark. Even the tranny fluid looked like it would in the bottle. Battery is new, air filter is new and the passenger air filter is a little dusty but completely acceptable. Makes me feel better that maybe they actually did all the maintainance including the differential. I'm still goin over there tomorrow to get the service record though.

[justin0469]

Today driving, I realized it said things in reverse. I can hear the rear diff during low speeds, about 45 and under. There maybe noise past that but is droned out with road and car noise. Is it still bad?

[2002sportside]

Personally I would just drain and refill the differential fluid for piece of mind. The FSM lists it as only a pint of fluid, $5 now is better than wondering and paying $2k later. I'd probably go to Toyota and get the fluid from them too. Old or contaminated fluid could definately be a cause...

[justin0469]

Think it would void my warranty?

[2002sportside]

Dealer can not void a warranty because you do your own work. It's illegal.

[justin0469]

Hm, interesting. Never heard that before. How can I prove that I did the work if something goes wrong and they try to say the work was never done since they didn't do it and I don't have a service receipt from anywhere?

[2002sportside]

If you think you need proof, save the receipt for the fluid. It will have the date you purchased it.

[justin0469]

OK, I think you convinced me. Once I get under there, I assume it is pretty obvious where the fill and drain plugs are for the rear differential? And for the transfer case since I might as well do them both? Owner's manual says 0.5qts for rear and 0.8qts for transfer case... What kind of fluid would I ask for? I am a newb when it comes to AWD components...

[2002sportside]

First, why does the FSM list capacities in pints and liters?? Anyway, both components call for 80w90 GL5 lube. I would go into a Toyota parts department and say, "I need two quarts of fluid for the rear diff in a Matrix." Thats (sort of) what I did when I needed fluid for a CRV. I had no idea what Honda called the fluid, but the parts guy did.My advise is to make sure the fill plug comes loose before you drain them. You don't want to find out the hard way you have no way to fill what you just drained... Have you called to see how much the dealer would want to change the fluid. I'm not a big fan of dealers, but if the price is low enough...

[justin0469]

I haven't called because they aren't open on weekends. I will call the Pontiac dealership on Monday to see, I have to go there anyways. Thanks for your help.

[justin0469]

I made an appointment for tomorrow morning. I went in today and they said the noise from the rear was investigated when traded in and was determined to be the tires... BSI told them I would understand tire noise if it was only highway speeds but moving from a stop I can hear it, barely moving. I don't think tires make noise like that going so slow. The noise doesn't sound like tire noise anyways. But hopefully tomorrow they will have an answer for me about that and the GPS problem. If they tell me tire noise again and the rear diff blows up 10k miles later, they get to pay for it.

[justin0469]

I guess they are replacing the differential bearings and they are seeing if they can replace the navigation head unit under warranty for me. Not that anyone is looking for updates but just in case.

[zionzr2]

Thanks !!Updates are always appreciated by me even if I dont say it.

[2002sportside]

I'm always curious on the outcome of a problem. I didn't realize you had just bought the car, I don't usually read all the forums... In that case I would have brought it to the dealer and had them fix it.