Need help, have a serious question. Grinding noise, loss of MPG

If it's still under warranty, I'm sure it is, they have to fix it. Leave it there, get a loaner, and tell them to give you a call when it's fixed!!!!! .02

 

Sounds like tires rubbing your wheel wells.

 

When it does it, put your truck up on Jack stands and check to see if all 4 are still engaged. Be sure you are on flat ground and there is no one in front of you in case your truck falls off the stands

 

Each dealership is suppose to have a set of chassis ears. They are little microphones that can be secured and you can listen to different ones to pinpoint the noise. The sound does sound like gears based off of the video. Almost reminds me of someone shifting a manual into the wrong gear. There have been a couple cases where the t-case has been getting confused and locks into 4-lo. Yours isn't in 4-lo. But maybe it too is getting confused. And when you hit the bump, the sleeve inside the t-case slides forward and makes contact with the gear. You may have been to many Toyota dealerships and feel like they won't help you. Which may be true....but you need to find one that will listen and help. Don't go in there demanding things or throwing words like "Lemon law" or anything crazy. Hell....i would maybe even ask to talk to the service manager and even say you would be willing to pay diagnosis. Even if it is covered under warranty. It's a win for both sides. You get your truck fixed and the tech involved will get his time covered. I work at a dealership and I'm always willing to help a customer out if they are willing to meet me halfway. Modifying a vehicle null and void warranties, but if you are dealing with a knowledgeable technician....KNOWLEDGEABLE....not dishonest....they will be able to help you out. Good luck. Off the record, I'm leaning towards the t-case just based on the video of someone else's rig.

 

Also, when that noise comes on and the light comes on..if you're not on the gas does it significantly slow the vehicle down? I don't remember reading but does it do this if the traction control is off? It definitely doesn't sound like any noise the read diff would make(and I've heard about any noise coming out of a rear diff there is lol). I almost wondered if the abs was trying to kick in as it kind of sounds like that but it would be more likely to me that it's coming from the Tcase or something along those lines.

 

The slip lights up when one of the wheels is off or slipping for a moment and its triggering the ABS and I "think" thats what the grinding is. Its upon a good amount of flex, like when you go into a steep parking lot at a good speed. Its only for a moment and then it stops.

 

I think its tcase/ABS related, caused by 4x4 not disengaging correctly. Most posts are leaning towards the Tcase and I feel strongly about it.

Its only the front that grinds and its gears... not tire rub as I have had both and felt both. they are distinctly different in sound and the feeling in the cab. This resonates from the central location or under the trans/tcase but Im not sure if they are the cause or its an actuator or hubs or something else I am not thinking of. The ABS light doesnt always have to come on to get the sound btw but, the sounds/grinding is almost always present when the light is illuminated.

Im worried about buying parts or paying for labor that may void the warranty or, cause them to say that I voided the warranty. I havent messed with trans or tcase and I was low on fluid from the factory. I dont have much faith that its not messed up but Im sure it could be fixed if they would investigate.

 

That's not my video. But my truck makes he exact same sound. It happens around sharp turns at high speed or sharp incline/decline. I assume the wheel looses traction.

 

Thanks man. I'm hoping others who have had this issue can shed some light.

 

Finally....

So I made an appointment with a master tech at the 3rd dealership in my area... It was for 2pm and supposed to be a ride along. I show up and they are like you need to leave because that tech isnt here.... Im like "can you just have someone ride with me to listen to this intense grinding noise" the service advisor is like "nope" and I lose my ish and ask him to get the manager and finally they send someone with me and wouldnt you know... after a year..... of bringing it in and explaining it to them. asking them for ride alongs and leaving the car they finally hear it and acknowledge it.

I made sure the tech told me and the advisor that he "knew it wasnt tire rub" or anything stupid like that so they cant blame it on random ish. It was def gears and he told me the advisor and manger that.


Long story short. They dont know what to do. They are going to write corp to see what they think.


If you have crappy MPG and when you go over incline/decline with a nasty grinding gear sound.... it is not normal. its related to the ABS system and when it detects slippage it actuates to limit slip which in turn grinds the gears. It could be causing damage to the tcase/ drive shaft and some gears so get it looked at and make sure a tech rides with you and you drive.. take them on steep inclines to reproduce. Dont leave your truck for them to try to reproduce as they wont even really look for it.


He also couldnt find the hard shift even though I told them its when its cold... not after Ive been driving all day.

 

Had an incident today where I heard a noise very similar to this. I was turning into a parking lot at speed and the bumps made the truck produce a sound like this.

 

Have you resolved this issue? My truck is a 6MT.

 

Did you test drive with Techstream in test mode?

The thresholds for wheel speed sensors DTC's are a joke and won't be stored.

Some will only store in test mode. C1282(Center Differential Lock Position Switch) comes to mind.

 

Are you sure this could be causing gears to grind. I went into a turn a little to fast and heard a sound similar to the one in your video. I did some research and the sound could be the ABS pump working hard and vibrating rather loudly.

 

I also believe its caused when the abs kicks in but its like grinding gears in my truck and rumbles the whole cab.. feels like its coming from the trans or tcase

 

Ill have to ask about that

 

Find a steep hill. Stop on an incline. Let off the brake and let it roll backwards. The traction control should kick in because it doesn't like that. Is that the same exact sound that's happening? Then you at least know what the sound is. Why it's engaging over speed bumps I don't know. Once and a while, it will kick on when I'm pulling into my driveway if I hit the right angle.

If that's not the same sound, then there's something else really wrong.

 

I never get that sound from a stop where the traction is kicking in to keep me from rolling back. mine will just sit quiet till I give it gas to get going.

this is all together something different related to the abs kicking in when there is flex in the truck and it detects slippage. when the ABS actuates its grinding some gears or something that I cant figure out and neither can toyota at this point.

They told me more than a week ago they would get back to me after they called corp... No call yet and when I called in there were no notes on my file with any updates.

 

ABS shouldn't be grinding gears though. If it's gears grinding, have you checked your drive shaft? If it goes beyond the angle it's supposed to I suppose it could sound odd but not sure what it would sound like.

 

The abs and limited slip are electronic. They will not cause gear grinding. You have something else going on. Have you changed the fluids in your t-case and diffs to check for foreign objects?