Whining noise through acceleration HELP (VIDEO)

[Jolly Roger]

So I just got my differentials and transmission fluids changed out last month and now Im getting this whining noise that has just gotten louder and louder.

Sounds like this guys truck in this video...turn it up and have a listen.

What could this sound be? Im beginning to think they forgot to put fluid back in the diff! My wife seems to think its coming from the transmission rather then from the rear of the truck....My truck isnt as loud as this one, but its the same sound that increases with speed and lets off during de-acceleration. Almost sounds like a car in reverse or shifted into 4x4.

 

[Fless]

It sounds like it's speed-related. For starters I'd be checking the diff fluids right away. Might check the tranny fluid, too, if it's hasn't been checked in a while.

You're not getting any wheel hop when turning on dry ground, are you?

 

[Jolly Roger]

It sounds like it's speed-related. For starters I'd be checking the diff fluids right away. Might check the tranny fluid, too, if it's hasn't been checked in a while.

You're not getting any wheel hop when turning on dry ground, are you?

Just checked the trans fluid, it was a half qt low if that and I topped it off. -Still making noise.
I picked it up last month from getting the fluids changed but then I noticed the noise and it just seems to be getting more pronounced.
I haven't checked the diff fluid because I cant right now.
No wheel hop.

 

[Jolly Roger]

So I took it in today and they said that there is metal shavings ect. must replace the pinion bearing...$900 estimate..

Having a hard time with this.

Been driving this rig for 5 years now with no problems and two weeks after having the diff fluid changed THIS happens?! WTH.

Strange coincidence..

 

[OR VietVet]

It does sound like a diff noise and the pinion is smaller on the 4.10 gear and I have seen them give up the ghost quicker than a higher gear. Total miles now? I see 75k on your signature but how often do you update that? What kind of towing have you been doing and how hard do you drive it? How hard does the wife drive it? Was anything said to you when the fluids were changed out? If I pay someone to do it I want a report of how it looks and pics to see for myself the condition of the gear teeth. Did they replace a pinion seal when they did that? Some techs mess up retensioning the pinion nut. How many miles were on the gears before the fluid was changed? Are you certain the correct fluid was used during the fluid changes?

 

[Jolly Roger]

I supplied the fluid last time and gave them 75-90 due to the colder weather here.

I just picked it up from the shop...($950) and the invoice says they used LSII Positrac Additive.
I have a G80 rpo code and from what I understand, that means its a locker and NOT a limited slip diff. ???

 

[Jolly Roger]

LOCKING DIFFERENTIAL LUBRICANT (SERVICE INFORMATION) #91-4-109
SUBJECT: LOCKING DIFFERENTIAL (G80) LUBRICANT - (SERVICE INFORMATION)
VEHICLES AFFECTED: ALL LIGHT TRUCKS EQUIPPED WITH G80 REAR AXLE ALL YEARS
Some light duty trucks equipped with locking rear axles (G80) may exhibit rear axle chatter, especially when turning a corner from a stop.
This condition of alternate engagement and disengagement of clutches in differential assembly is usually caused by contaminated axle lubricant.
To correct this condition, drain and refill the rear axle with SAE 80W-90 GL5 (P/N 10950849).

The use of any additive in locking rear axles (G80) is not recommended. Rear axle additives are designed for use in limited slip differentials which are normally installed in cars. All light duty trucks equipped with RPO G80 make use of a locking differential and the use of additives will delay the engagement of the locking mechanism and may decrease axle life.

VEHICLES/COMPONENTS INVOLVED: ------------------------- ---- Some light duty trucks equipped with locking rear axles, RPO G80.
SERVICE PARTS INFORMATION:
Part Number Description ----------- ------------------ 10950849 Lubricant, Rear Axle (1 litre)
Parts are currently available through CANSPO.
WARRANTY INFORMATION:
As specified in Light Duty Truck Maintenance Schedules, locking rear axle fluid drain and refill is required owner maintenance at the first engine oil change. Failure to drain and refill the rear axle as specified may contribute to a later axle chatter condition. Refer to the appropriate Light Duty Truck Maintenance Schedule or service manual, section OB, for further details on change intervals.
General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.
© Copyright General Motors Corporation. All Rights Reserved.

 

[Jolly Roger]

Do I need to have them drain it?

 

[OR VietVet]

G80 Axle Positraction, Limited Slip

During normal driving conditions, the MLocker (G80) functions as a light-bias limited slip differential. When a low-traction situation occurs that causes a wheel speed difference greater than 100 RPM, a flyweight mechanism opens to engage a latching bracket.

Sounds like you should drain and add the correct fluid to give it a chance. "10950849 Lubricant, Rear Axle (1 litre)"

This is exactly why, no matter what the weather conditions are, I always add the called for fluid and don't mess with a guess that it needs.


When you took it in did they show you the metal shavings? They should have or at least supplied cell pics of what they saw.

 

[Jolly Roger]

Also came across this...https://www.gm-trucks.com/forums/topic/100031-g80-rpo-code/

 

[Jolly Roger]

G80 Axle Positraction, Limited Slip

During normal driving conditions, the MLocker (G80) functions as a light-bias limited slip differential. When a low-traction situation occurs that causes a wheel speed difference greater than 100 RPM, a flyweight mechanism opens to engage a latching bracket.

Sounds like you should drain and add the correct fluid to give it a chance. "10950849 Lubricant, Rear Axle (1 litre)"

This is exactly why, no matter what the weather conditions are, I always add the called for fluid and don't mess with a guess that it needs.


When you took it in did they show you the metal shavings? They should have or at least supplied cell pics of what they saw.

No pictures. I did everything short of accuse them of not putting fluid in after they drained it last time...didnt mean to...
I asked the receptionist (here lies the problem) if the ring and pinion were ok sense they described metal shavings in the diff..he said just the pinion bearing was really bad and the R&P were ok...
never get actual conversation w/ mechanics at this place.

 

[Jolly Roger]

G80 rpo in cars means it is a limited slip...
G80 in a light truck means its a locker...

Right? They should not have put an additive in my diff?





@swathdiver

 

[gooffeyguy]

From what I've read in the past, when using GM recommended fluid (GL5 P/N 10950849 like stated above) no additive is needed because it's already in the fluid.

 

[Jolly Roger]

double post

 

[96-2D-Hoe]

That additive used to be blue. Service manager was always telling my G80 needed it. If it still is blue you might want to check the fluid to see if they actually put it in there.

But that sucks. Mine screwed up around 95k if it makes you feel any better

 

[Jolly Roger]

That additive used to be blue. Service manager was always telling my G80 needed it. If it still is blue you might want to check the fluid to see if they actually put it in there.

But that sucks. Mine screwed up around 95k if it makes you feel any better

The invoice above says the did. This is my question. Should they have put it in or not?

 

[96-2D-Hoe]

AFAIK it is not used for the G80. That's what the bulletin says right?

 

[Jolly Roger]

AFAIK it is not used for the G80. That's what the bulletin says right?

Thats what Im trying to determine for sure. Does a 2007 Tahoe 4x4 with a G80 rpo code have limited slip diff? .....or is it a locker?

 

[96-2D-Hoe]

That I don't know. I know very little and it's all related to my 96 OBS. Someone will

 

[Jolly Roger]

Heck, if they added the limited slip additive the first time I brought it in for a fluid change, could that have cause it to start whining and damaged it?