Grinding in Rear, Ticking/Resistance in front (while turning)
02-05-2012, 07:45 PM
#1
1st Gear
Thread Starter
Member Since: Feb 2012
Location: Falls Church VA
Posts: 1
Likes: 0
Received 0 Likes
on
0 Posts
Grinding in Rear, Ticking/Resistance in front (while turning)
So yeah, I bought a C6 2008 corvette, and it seems while at low speeds when I am turning hard right or left, feels like resistance on the wheels like its jolting, and in the back it sounds like grinding I dont know if its just loose calipars in the back gridning against the roaders but I doubt that. I am new to corvettes and any suggestions before I bring it some place and probably get lied to would be help. (I'm in the Army and just moved to the DC area don't have a mechanic here so will probably get screwed over a few times before I find someone honest so any help would be great) thanks!!
02-05-2012, 09:42 PM
#2
Team Owner
Welcome to the Forum!!! Congratulations on your '08!! Hope you enjoy it. 
The front wheel jolting while turning hard is just a normal function of the wide tires. The outside edge of the tire has to travel farther than the inside edge so it skips a little. No issue there.
The grinding in the back is "most likely" the posi-traction. GM changed the type of differential fluid in '08. The new one doesn't need an additional friction modifier and works wonders for what you are describing. Here's the TSB on it:
Good luck, have fun and thank you for your service.
The front wheel jolting while turning hard is just a normal function of the wide tires. The outside edge of the tire has to travel farther than the inside edge so it skips a little. No issue there.
The grinding in the back is "most likely" the posi-traction. GM changed the type of differential fluid in '08. The new one doesn't need an additional friction modifier and works wonders for what you are describing. Here's the TSB on it:
Subject: Rear Axle Clunk and/or Chatter Type Noise on Turns
(Drain/Refill Rear Differential Fluid) #07-04-20-002A - (01/09/2008)
Models: 2004-2008 Cadillac XLR (Including V-Series and Export)
2005-2008 Chevrolet Corvette (Including Z06 and Export)
This bulletin is being revised to change the fluid recommendation and to remove the requirement of adding friction modifier. Please discard Corporate Bulletin Number 07-04-20-002 (Section 04 -- Driveline/Axle).
Condition:
Some customers may comment on a clunk and/or chatter type noise from the rear of the vehicle while making turns.
Cause:
This condition may be caused by slip/stick of the posi-traction clutch plates due to insufficient limited-slip axle additive. As plates slip and stick, a jumping or jerking feel occurs accompanied by a clunk noise.
Correction:
Important: DO NOT remove the differential cover from the rear or the two sides. It is not necessary to flush the old fluid from the differential.
Drain and refill the rear differential fluid using the procedure listed below.
Draining Procedure:
Raise and support the vehicle. Clean any dirt from around the differential drain plug. If not equipped with a differential cooler, remove the drain plug (1) and washer (2) from the differential.
If equipped with a differential cooler: 4.1. Using a bent tip screwdriver, remove the quick connect fitting retaining ring (3) from the quick connect fitting (4) and discard the retaining ring.
4.2. Remove the differential cooler inlet pipe from the differential nut.
Drain the fluid.
Filling Procedure:
If not equipped with a differential cooler, install the drain plug (1) and washer (2) to the differential. Tighten the differential drain plug to 35 N•m (26 lb ft).
If equipped with a differential cooler: 2.1. Install a new retaining ring.
2.2. Connect the differential cooler pump inlet pipe (2) to the differential. A distinct snap should be heard or felt when assembling the cooler pipe to the fitting.
2.3. To ensure the cooler line is properly installed, give the cooler pipe a gentle pull.
Clean any dirt from around the differential fill plug. Remove the fill plug and washer from the differential.
Important: DO NOT add any limited-slip additive (friction modifier). With this new fluid (Dexron LS Gear Oil 75W-90) it is no longer required to add friction modifier. If friction modifier is added, it will cause the fluid to lose some of it's friction reducing properties as well as reducing seal life.
Fill the differential with the new DEXRON® LS gear oil, P/N 88862624 (Canadian P/N 88862625). Refer to the table listed below for lubrication specifications.
Check the fluid level to ensure it is even with the bottom of the fill plug hole to no lower than 6 mm (0.25 in) below the opening. Install the fill plug and washer to the differential. Tighten the differential fill plug to 35 N•m (26 lb ft).
Important: Steps 8-13 are for vehicles equipped with the differential cooling system. For vehicles not equipped with the cooling system, proceed to step 14.
Raise the vehicle so the wheels are about a foot off the floor. Make sure the wheels can spin freely without obstruction from the hoist or any nearby items. Start the vehicle and put the transmission in second gear. Slowly accelerate to 10 mph and hold this speed for one minute. Turn the vehicle off. Raise the vehicle. Check the fluid level in the differential. Add fluid until the recommended level is reached. Lower the vehicle.
Once the differential fluid has been changed, the vehicle must be driven in 8-10 tight figure eight maneuvers to heat the fluid and allow the fluid to be worked into the clutch plates.
Lubrication Specifications Application
2004-2005 XLR (Including Export) and 2005 Corvette (Non Export)
1.72 liters
1.85 quarts
2006-2008 XLR (Including V-Series and Export) and 2006-2008 Corvette (Non Z06)(Non Export)
2.0 liters
2.11 quarts
2005 Corvette Export
1.88 liters
1.99 quarts
2006-2008 Corvette Export (Non Z06)
2.16 liters
2.28 quarts
2006-2008 Corvette Z06
2.75 liters
2.91 quarts
Parts Information:
Description: DEXRON® LS Gear Oil
Part Numbers:
88862624 (US-1 Quart)
88862625 (Canada-1 Liter)
Warranty Information
For vehicles repaired under warranty, use:
Labor Operation: F9709*
Description: Drain & Refill Rear Axle Fluid
Labor Time: 0.6 hr
* This is a unique labor operation number for bulletin use only. It will not be published in the Labor Time Guide.
© Copyright General Motors Corporation. All Rights Reserved.
(Drain/Refill Rear Differential Fluid) #07-04-20-002A - (01/09/2008)
Models: 2004-2008 Cadillac XLR (Including V-Series and Export)
2005-2008 Chevrolet Corvette (Including Z06 and Export)
This bulletin is being revised to change the fluid recommendation and to remove the requirement of adding friction modifier. Please discard Corporate Bulletin Number 07-04-20-002 (Section 04 -- Driveline/Axle).
Condition:
Some customers may comment on a clunk and/or chatter type noise from the rear of the vehicle while making turns.
Cause:
This condition may be caused by slip/stick of the posi-traction clutch plates due to insufficient limited-slip axle additive. As plates slip and stick, a jumping or jerking feel occurs accompanied by a clunk noise.
Correction:
Important: DO NOT remove the differential cover from the rear or the two sides. It is not necessary to flush the old fluid from the differential.
Drain and refill the rear differential fluid using the procedure listed below.
Draining Procedure:
Raise and support the vehicle. Clean any dirt from around the differential drain plug. If not equipped with a differential cooler, remove the drain plug (1) and washer (2) from the differential.
If equipped with a differential cooler: 4.1. Using a bent tip screwdriver, remove the quick connect fitting retaining ring (3) from the quick connect fitting (4) and discard the retaining ring.
4.2. Remove the differential cooler inlet pipe from the differential nut.
Drain the fluid.
Filling Procedure:
If not equipped with a differential cooler, install the drain plug (1) and washer (2) to the differential. Tighten the differential drain plug to 35 N•m (26 lb ft).
If equipped with a differential cooler: 2.1. Install a new retaining ring.
2.2. Connect the differential cooler pump inlet pipe (2) to the differential. A distinct snap should be heard or felt when assembling the cooler pipe to the fitting.
2.3. To ensure the cooler line is properly installed, give the cooler pipe a gentle pull.
Clean any dirt from around the differential fill plug. Remove the fill plug and washer from the differential.
Important: DO NOT add any limited-slip additive (friction modifier). With this new fluid (Dexron LS Gear Oil 75W-90) it is no longer required to add friction modifier. If friction modifier is added, it will cause the fluid to lose some of it's friction reducing properties as well as reducing seal life.
Fill the differential with the new DEXRON® LS gear oil, P/N 88862624 (Canadian P/N 88862625). Refer to the table listed below for lubrication specifications.
Check the fluid level to ensure it is even with the bottom of the fill plug hole to no lower than 6 mm (0.25 in) below the opening. Install the fill plug and washer to the differential. Tighten the differential fill plug to 35 N•m (26 lb ft).
Important: Steps 8-13 are for vehicles equipped with the differential cooling system. For vehicles not equipped with the cooling system, proceed to step 14.
Raise the vehicle so the wheels are about a foot off the floor. Make sure the wheels can spin freely without obstruction from the hoist or any nearby items. Start the vehicle and put the transmission in second gear. Slowly accelerate to 10 mph and hold this speed for one minute. Turn the vehicle off. Raise the vehicle. Check the fluid level in the differential. Add fluid until the recommended level is reached. Lower the vehicle.
Once the differential fluid has been changed, the vehicle must be driven in 8-10 tight figure eight maneuvers to heat the fluid and allow the fluid to be worked into the clutch plates.
Lubrication Specifications Application
2004-2005 XLR (Including Export) and 2005 Corvette (Non Export)
1.72 liters
1.85 quarts
2006-2008 XLR (Including V-Series and Export) and 2006-2008 Corvette (Non Z06)(Non Export)
2.0 liters
2.11 quarts
2005 Corvette Export
1.88 liters
1.99 quarts
2006-2008 Corvette Export (Non Z06)
2.16 liters
2.28 quarts
2006-2008 Corvette Z06
2.75 liters
2.91 quarts
Parts Information:
Description: DEXRON® LS Gear Oil
Part Numbers:
88862624 (US-1 Quart)
88862625 (Canada-1 Liter)
Warranty Information
For vehicles repaired under warranty, use:
Labor Operation: F9709*
Description: Drain & Refill Rear Axle Fluid
Labor Time: 0.6 hr
* This is a unique labor operation number for bulletin use only. It will not be published in the Labor Time Guide.
© Copyright General Motors Corporation. All Rights Reserved.
Good luck, have fun and thank you for your service.
02-05-2012, 10:28 PM
#3
Le Mans Master
So yeah, I bought a C6 2008 corvette, and it seems while at low speeds when I am turning hard right or left, feels like resistance on the wheels like its jolting, and in the back it sounds like grinding I dont know if its just loose calipars in the back gridning against the roaders but I doubt that. I am new to corvettes and any suggestions before I bring it some place and probably get lied to would be help. (I'm in the Army and just moved to the DC area don't have a mechanic here so will probably get screwed over a few times before I find someone honest so any help would be great) thanks!!
With the front wheels cranked - especially when it's cold - the tires will groan and slip. This will improve significantly when it's hot.
The noise could be the front tires sounding like the rear end (noises are funny like that) or the LSD chatter that can be cleared-up by filling with GM's latest-greatest rear end fluid.
02-06-2012, 12:56 AM
#4
Supporting Vendor
Member Since: Apr 2011
Location: Frederick Maryland
Posts: 3,178
Likes: 0
Received 147 Likes
on
111 Posts
St. Jude Donor '08-'09-'10-'11-'12, '14-'15-'16-'17-'18
So yeah, I bought a C6 2008 corvette, and it seems while at low speeds when I am turning hard right or left, feels like resistance on the wheels like its jolting, and in the back it sounds like grinding I dont know if its just loose calipars in the back gridning against the roaders but I doubt that. I am new to corvettes and any suggestions before I bring it some place and probably get lied to would be help. (I'm in the Army and just moved to the DC area don't have a mechanic here so will probably get screwed over a few times before I find someone honest so any help would be great) thanks!!
__________________
