Strange noise after chaing differential fluids

[camdz]

Strange noise after changing differential fluids

**It wont let me change the typo in the thread title. I was in a hurry and not paying attention....**


This is on an 05 V6 4WD with 75k

This weekend I changed my front diff, rear diff and transfer case fluids. I switched them over to 75w-90 Redline synthetic. Yesterday I noticed a noise that almost imitates a cupped tire, but at a slower rhythm (if that makes sense). Like if the tire had just one flat spot on it. Its somewhere in between a hum and a growl, but very low pitched and consistent in volume. I was set on rotating my tires to see if the sound moved to somewhere else, when I realized that it wasnt making this noise on my "test drive" after finishing the fluids.

So today I decide to drive it in 4wd for a bit (like I did on the test drive), and of course it drives great. After putting it back in 2wd, the noise returns.

The noise comes around every second or so. Doesnt matter what speed you are going. It goes at the same pace. Its clearly something that is spinning though, but its so slow in comparison to my speed, Im at a loss on what to check. Any ideas? The fluid level in the front diff is good.

Could it be something as simple as drive train harmonics coming through the car, skid plates, exhaust somehow? I find it hard to believe putting fresh fluid in would cause a problem to surface immediately like that.

The simple solution would be to drive it around in 4wd forever but its been bothering me haha. I am driving to Colorado for some early season snowboarding on Thursday from Kansas City, and am hoping to figure this out before then.

Im getting ready to crawl back under there in a bit, just to triple check everything and hope to find something obvious. Ive done lots of searching on the internet but most people have problems with gear whining, drive shaft thump, wheel bearings, etc. Its not anything like those.


Edit- I also added grease to all of the zerk fittings. I did this the same way Ive been doing it since Ive owned the car though, and am careful not to put too much in (just to be safe).

 

[camdz]

Hmm.

Any suggestions at all? I checked everything out yesterday and all looked well. I did a tire rotation but the noise is the same and coming from the same area. I did notice that the rotation of the noise is slower as I come to a stop. But above say 30 mph its the same pace. I took it on the highway up to about 80 and it never gets any faster. Only slower when coming to a stop. Brakes dont seem to effect it either. Its there whether Im on the brakes, coasting, on the throttle, etc.

I have no idea what it could be, and its really annoying.

 

[CJ3Flyr]

Redline is good stuff... Is it the best? Who knows, is it really good? Heck yeh...

I would confirm my fluid levels one more time.

When greasing did you pump the rear driveshaft slip-joint totally full untill the pump on the grease gun got stiff? If so you may have over stuffed it and the vehicle is picking up a harmonic through the drivetrain.

If that's the case unscrew the zerk, jack it up to near full axle extension and then let it down and then let it down. Take it out, smack a few speed bumps to compress the the rear axle. That'll spit out any extra. Screw the zerk back in and don't worry about it. That's my 2cents. (Not that I pumped too much in the slip-joint the first time:bash: :lmao: )

If your fluid is full you're probably 100% fine... :cheers:

 

[camdz]

Redline is good stuff... Is it the best? Who knows, is it really good? Heck yeh...

I would confirm my fluid levels one more time.

When greasing did you pump the rear driveshaft slip-joint totally full untill the pump on the grease gun got stiff? If so you may have over stuffed it and the vehicle is picking up a harmonic through the drivetrain.

If that's the case unscrew the zerk, jack it up to near full axle extension and then let it down and then let it down. Take it out, smack a few speed bumps to compress the the rear axle. That'll spit out any extra. Screw the zerk back in and don't worry about it. That's my 2cents. (Not that I pumped too much in the slip-joint the first time:bash: :lmao: )

If your fluid is full you're probably 100% fine... :cheers:

I double checked fluid levels, and all are just barely dripping from the fill hole. I will check again though. I had the vehicle level in my driveway. As far as the rear drive shaft slip joint..I definitely did not go until it got hard to pump. Ive always been paranoid as when to stop. I probably did 6-7 pumps but have no idea if that was enough or too much. I am doing this tomorrow regardless and hope that it fixes my problem!

I will report back tomorrow with results. The thought of too much grease in there has been in the back of my head, but I never thought of a way to remove excess.

 

[<<<<]

Most people here done DIY fluid changes and no problem with diffs. Are you sure it's not tire or brakes? Because I cant think of anything that can go wrong with your change. Im sure you used all quarts in 75w90. When I was buying my Royal Purple dude gave me 2quarts of 75w90 and 5 of 90w140. I noticed it right there and had him find right weight.

 

[camdz]

Most people here done DIY fluid changes and no problem with diffs. Are you sure it's not tire or brakes? Because I cant think of anything that can go wrong with your change. Im sure you used all quarts in 75w90. When I was buying my Royal Purple dude gave me 2quarts of 75w90 and 5 of 90w140. I noticed it right there and had him find right weight.

Yes, all quarts were 75w90. I crawled under one last time on a level surface without ramps or anything to check fluid levels. All were good. I make sure nothing was rubbing on the skids, and that nothing was out of place either. Re installed them very carefully.

After driving to Colorado Im trying to convince myself its tire noise, but I dont know why it started on the same day. Im just going to call it good since everything I did has checked out fine, and everything appears normal. We will see how it goes from here.

As far as brakes, Ive never known them to cause a low drone/hum noise like I am hearing. I may check them out when I get back to KS. The feel of my brakes hasnt changed and they are still smooth when applying pressure.

I didnt notice it much on the highway here (CO), but have definitely heard it since. Im chalking it up as a mystery for now.

 

[camdz]

I have to bump this back to the top. Its driving me insane. I got under the car again today and went over EVERYTHING. Ive since rotated tires every way imaginable, and its not that.

Does anyone think the Redline synthetic fluid could be to blame? Im halfway tempted to swap out one diff at a time with a different gear oil to see if anything changes. Its kinda costly and could be a complete waste of time, but I dont know what else to look for.

The noise stops the very second I engage 4wd, like clock work, every time.

 

[kaneman23]

I have to bump this back to the top. Its driving me insane. I got under the car again today and went over EVERYTHING. Ive since rotated tires every way imaginable, and its not that.

Does anyone think the Redline synthetic fluid could be to blame? Im halfway tempted to swap out one diff at a time with a different gear oil to see if anything changes. Its kinda costly and could be a complete waste of time, but I dont know what else to look for.

The noise stops the very second I engage 4wd, like clock work, every time.

I would start w\the rear diff and swap the fluid for some M1. No idea what it could be. Perhaps the batch you bought was mislabled??

 

[camdz]

Is this the M1 that everyone is using? Ive seen both the "LS" and plain labeled bottles. I know what LS stands for but I just wanted to make sure its the same kind everyone is putting in their trucks. The auto parts stores around me only have the "LS" on the shelves and I know the 4runner doesnt actually have a limited slip.

I hate wasting the money Ive already put into it, but it cant be anything else. Unless my truck just simply doesnt like synthetic gear oil to begin with. Would it make a difference if I went back to a regular gear oil of the same weight?

 

[Uneek]

Is this the M1 that everyone is using? Ive seen both the "LS" and plain labeled bottles. I know what LS stands for but I just wanted to make sure its the same kind everyone is putting in their trucks. The auto parts stores around me only have the "LS" on the shelves and I know the 4runner doesnt actually have a limited slip.

That's what I put in mine.

 

[camdz]

It probably wont help to bring this back to the top but its worth a shot.

My latest update- Still doing it. I have since changed the fluids again, and it ended up being a waste of time and money. Makes me wish I would have bought a warranty for this thing. I cant afford to have it at the dealer 10 times to get a different answer each visit, and have them start guessing at which part to replace next.

 

[Overland Warehouse]

I use the 75/140 in my '04 with 140,000miles. Before than, always 75/90. doubt your problem is oil levels.

 

[chayos00]

It probably wont help to bring this back to the top but its worth a shot.

My latest update- Still doing it. I have since changed the fluids again, and it ended up being a waste of time and money. Makes me wish I would have bought a warranty for this thing. I cant afford to have it at the dealer 10 times to get a different answer each visit, and have them start guessing at which part to replace next.

I guess depending on how loud this noise is, the only other way to get rid of it would be to drown it out with loud music.

 

[camdz]

I use the 75/140 in my '04 with 140,000miles. Before than, always 75/90. doubt your problem is oil levels.

Its definitely not oil levels, but I needed to rule it out for peace of mind.

For now, the radio is my fix, but it still makes me wonder if I am doing damage to something. 99% of people in my car would tell me its tire noise. It sounds exactly like that...but switching it to 4wd and having the noise instantly disappear throws that out the window.

 

[415runner562]

camdz,

I'm having a similar issue as well, but it only happens around 40mph or lower. If I'm accelerating and I'm going less than 40mph, it goes away... let go of the gas and it comes back. Braking... popping/grinding noise is sometimes there.

 

[camdz]

camdz,

I'm having a similar issue as well, but it only happens around 40mph or lower. If I'm accelerating and I'm going less than 40mph, it goes away... let go of the gas and it comes back. Braking... popping/grinding noise is sometimes there.

Yours sounds much different. In a way I wish mine would do something like that, just so I would have somewhere to start.

Have you checked your calipers/pads by chance?

 

[00328]

Its definitely not oil levels, but I needed to rule it out for peace of mind.

For now, the radio is my fix, but it still makes me wonder if I am doing damage to something. 99% of people in my car would tell me its tire noise. It sounds exactly like that...but switching it to 4wd and having the noise instantly disappear throws that out the window.

Have the dealer check it out, take a tech for a drive, I wouldn't think it would cost very much for them to at least inspect it.

 

[camdz]

Have the dealer check it out, take a tech for a drive, I wouldn't think it would cost very much for them to at least inspect it.

I probably will eventually. I was just hoping someone else had a similar problem. When its warm out, I dont notice it, so I guess it will be fixed soon enough...:lol:

 

[Burt]

If noise goes away in 4WD, then that would indicate a transfer/center diff issue or front drive line issue. I would check to make sure the front drive line is really dis-engaging in 2WD. A trans-axle? I know this sounds to coincidental but strange things happen.

 

[Vic110793]

Same issue after diff change front and rear. Toyota dealership it’s a driveshaft issue. $1100 OTD price. Not sure what to believe. Would the diff change caused driveshaft problems?