2007 Tahoe - severe whining and grinding in reverse and over 10mph

[hotrod_cannit]

Today my 2007 Tahoe (LS 5.3L V8 Flex Fuel) made a horrendous grinding/whining sound as we were driving down the road at about 45-50 mph. It sounded like it was coming from the front left portion of the car. It almost sounds like it's 'free-spinning' on wet pavement, but it's not physically doing that. we pulled over and turned off the car, restarted and put it in drive. When we reached 10mph and the car tried to shift the noise happened again. As I braked the whining/grinding sound slowed and stopped once I stopped. I put the car in reverse and as soon as I did the whining/grinding sounds immediately started without the car moving, my foot still on the brake. We tried driving in 3rd, 2nd, and 1st as well with the same symptoms. I tried to engage the 4wd both hi and lo, and still had the same issues.
I've also been having issues over the last few months with my 4wd engaging when it wants (with the auto 4wd function off and in 2wd), and not engaging when I try to do so. The stabilitrak light comes on and off when it wants, and occasionally I will brake hard or take off quickly and the wheels have made sounds as if they are not quite engaged but 'rubbing' against something as if trying to go into 4wd all of a sudden.

So here's what we've tried so far:
- unplugged the 4wd fuse, the transfer case fuse, the battery, the transfer case wires. All resulted in the same symptoms - no change to the sounds. All have been plugged back in.
* when we unplugged the transfer case wires we put it in drive and with no shifting capabilities we were able to get to 15-20 mph before the noises started...so again, no change. We've plugged those back in
- we replaced the actuator back in October, and it didn't seem to fix the 4wd auto engage issues, but now it sounds as if it may be the culprit....

We trailered it home and chose to push it off onto the drive way for fear of using reverse.

We are capable of doing the labor for the fix, but not sure where to start. Every forum I've looked at isn't quite what we're experiencing, or it's for an older model. So I'm looking for suggestions/experience from anyone who has been in this similar situation.

Currently there are about 170,000 miles on it, and I'm the second owner. I bought it used from a dealer back in 2015, and I haven't had any issues up until late summer 2018.
Any help or direction is appreciated.

 

[thompsoj22]

from your description i would guess the transfercase has grenaded, either the planetary,shaft,chain. i think it is the only way that somthing is being allowed to spin without the wheels moving. either way you are probably faced with a transfercase/trans rebuild whichever component is bad. since the car is broke and you should not drive it at all, pull the drain plug on the transfercase and see if any metal comes out? it is only about two qts of fluid. this guess is based upon no noise when in "park" at an idle or any rpm for that matter. is the forward shaft spinning when in drive/reverse stopped with the brakes on?

 

[swathdiver]

Welcome to the forum Candice. You really need to have the vehicle scanned for the codes that will undoubtedly be stored inside the computers. I'm wondering if it is the ABS module myself. Do you know someone with a Tech-2 or other bi-directional scan tool?

 

[donjetman]

flexplate or torque converter bolts?

 

[Wolfbraid]

Possibly wheel bearings? Jack up the front, and try to spin the wheel(if it offers a bunch of resistance will feel grindy), then try turn the wheel back and forth(grab at 3 and 9 oclock and wiggle the wheel) if it clinks or clunks could be the bearing.

 

[KierstenBri]

Today my 2007 Tahoe (LS 5.3L V8 Flex Fuel) made a horrendous grinding/whining sound as we were driving down the road at about 45-50 mph. It sounded like it was coming from the front left portion of the car. It almost sounds like it's 'free-spinning' on wet pavement, but it's not physically doing that. we pulled over and turned off the car, restarted and put it in drive. When we reached 10mph and the car tried to shift the noise happened again. As I braked the whining/grinding sound slowed and stopped once I stopped. I put the car in reverse and as soon as I did the whining/grinding sounds immediately started without the car moving, my foot still on the brake. We tried driving in 3rd, 2nd, and 1st as well with the same symptoms. I tried to engage the 4wd both hi and lo, and still had the same issues.
I've also been having issues over the last few months with my 4wd engaging when it wants (with the auto 4wd function off and in 2wd), and not engaging when I try to do so. The stabilitrak light comes on and off when it wants, and occasionally I will brake hard or take off quickly and the wheels have made sounds as if they are not quite engaged but 'rubbing' against something as if trying to go into 4wd all of a sudden.

So here's what we've tried so far:
- unplugged the 4wd fuse, the transfer case fuse, the battery, the transfer case wires. All resulted in the same symptoms - no change to the sounds. All have been plugged back in.
* when we unplugged the transfer case wires we put it in drive and with no shifting capabilities we were able to get to 15-20 mph before the noises started...so again, no change. We've plugged those back in
- we replaced the actuator back in October, and it didn't seem to fix the 4wd auto engage issues, but now it sounds as if it may be the culprit....

We trailered it home and chose to push it off onto the drive way for fear of using reverse.

We are capable of doing the labor for the fix, but not sure where to start. Every forum I've looked at isn't quite what we're experiencing, or it's for an older model. So I'm looking for suggestions/experience from anyone who has been in this similar situation.

Currently there are about 170,000 miles on it, and I'm the second owner. I bought it used from a dealer back in 2015, and I haven't had any issues up until late summer 2018.
Any help or direction is appreciated.

Did you ever find the problem? We have a 2007 Tahoe that is currently doing this exact same thing.. my husband just finished replacing the transfer case and that didn’t fix it… please let me know if you found a solution..

 

[B-train]

My guess is internal transmission issues. Above 10 mph, it was most likely shifted into 2nd gear and then the noise started. I believe reverse uses the 2nd gear clutch, so that would explain why the noise was present with no wheels moving.

Check the fluid level and color.

@NickTransmissions

 

[NickTransmissions]

My guess is internal transmission issues. Above 10 mph, it was most likely shifted into 2nd gear and then the noise started. I believe reverse uses the 2nd gear clutch, so that would explain why the noise was present with no wheels moving.

Check the fluid level and color.

@NickTransmissions

Would depend on which transmission is in that vehicle but if it's a 4L60E, reverse has it's own dedicated clutch packs (reverse input and low reverse) while 2nd gear is achieved via the forward clutch, band and second gear servo. If a 6L80E, reverse is achieved via the low reverse clutch pack and 3-5-R clutch while 2nd gear is achieved via the application of the 1-2-3-4 clutch and 2-6 clutch. The 4L80E uses the forward and intermediate clutch in combination with the intermediate sprag on the direct drum holding while in 2nd gear. Reverse is achieved by application of the rear band and direct clutch simultaneously.

All that said (and to your point) no noises in first gear but in appearing in 2nd could indicate front planetary gear set failure but the presence of the transfer case always complicates things. A couple days ago on another forum, someone posted about a similar, horrid grinding noise that turned out to be t case (snap ring had broken in half causing internals to come out of mesh and grenade themselves).

Today my 2007 Tahoe (LS 5.3L V8 Flex Fuel) made a horrendous grinding/whining sound as we were driving down the road at about 45-50 mph. It sounded like it was coming from the front left portion of the car. It almost sounds like it's 'free-spinning' on wet pavement, but it's not physically doing that. we pulled over and turned off the car, restarted and put it in drive. When we reached 10mph and the car tried to shift the noise happened again. As I braked the whining/grinding sound slowed and stopped once I stopped. I put the car in reverse and as soon as I did the whining/grinding sounds immediately started without the car moving, my foot still on the brake. We tried driving in 3rd, 2nd, and 1st as well with the same symptoms. I tried to engage the 4wd both hi and lo, and still had the same issues.
I've also been having issues over the last few months with my 4wd engaging when it wants (with the auto 4wd function off and in 2wd), and not engaging when I try to do so. The stabilitrak light comes on and off when it wants, and occasionally I will brake hard or take off quickly and the wheels have made sounds as if they are not quite engaged but 'rubbing' against something as if trying to go into 4wd all of a sudden.

So here's what we've tried so far:
- unplugged the 4wd fuse, the transfer case fuse, the battery, the transfer case wires. All resulted in the same symptoms - no change to the sounds. All have been plugged back in.
* when we unplugged the transfer case wires we put it in drive and with no shifting capabilities we were able to get to 15-20 mph before the noises started...so again, no change. We've plugged those back in
- we replaced the actuator back in October, and it didn't seem to fix the 4wd auto engage issues, but now it sounds as if it may be the culprit....

We trailered it home and chose to push it off onto the drive way for fear of using reverse.

We are capable of doing the labor for the fix, but not sure where to start. Every forum I've looked at isn't quite what we're experiencing, or it's for an older model. So I'm looking for suggestions/experience from anyone who has been in this similar situation.

Currently there are about 170,000 miles on it, and I'm the second owner. I bought it used from a dealer back in 2015, and I haven't had any issues up until late summer 2018.
Any help or direction is appreciated.

Drop the transmission pan and check for kibbles and bits...Would be a good idea to service it anyways, if it hadn't been done so in a while...Also drain the t case, looking for metal shavings, etc...Some of those transfer cases get 'case rub' where the inner portion of the casting gets eaten away by the chain, etc and the back half of the t case needs to be replaced...This applies mostly to the NP246 (RPO code = NP8).

Please let us know what you find or what you determine the problem to be.