open or limited slip

[DaDenaliDude]

Hello everyone, I am getting ready to replace my front and rear differential fluids. A long with the transfer case fluid. I’m going to use 75-90 Amsoil for the diffs. I found through the threads on here where someone noted the fluid capacity’s so thank you for that. But I’m not sure if I am supposed to use an additive in the rear diff. I’ve heard mixed opinions on this. Most people say that if you have a LSD then you do need to add it. But I’m not sure what type of diff I have either. Also I know I have to remove the cover on the rear one, and I can’t find a straight answer on if I’m going to need a new gasket or if mine has a reusable one. I have a 2007 Yukon Denali. This will be the first time I change these fluids.

 

[OR VietVet]

Put the fluid in that your owner's manual recommends. Have a new gasket at the ready, if needed. Make sure to sight down the sealing surface on the cover and use a ball peen hammer to flatten back out, if needed. Your manual will also give you capacities.

 

[DaDenaliDude]

Put the fluid in that your owner's manual recommends. Have a new gasket at the ready, if needed. Make sure to sight down the sealing surface on the cover and use a ball peen hammer to flatten back out, if needed. Your manual will also give you capacities.

My manual doesn’t say anything about additives. It just says use 75-90. How can you tell what type of diff you have?

 

[OR VietVet]

If your RPO code sticker says G80, you have the LSD. If the manual says nothing about additives, then use no additives.

 

[DaDenaliDude]

If your RPO code sticker says G80, you have the LSD. If the manual says nothing about additives, then use no additives.

I’m going to check to see if I have that code. Thanks

 

[donjetman]

My Denali has the G80 differential and I have been running Amsoil SG 75w-90 for 5 yrs and 60k+ miles. No issues.

 

[Ibustbravo]

Here's some intel.. Front then rear axle specs listed.

I look all this data up, walk over to my cabinet of oils and say.. Hmm.. I have enough of this other stuff.. it'll do. Edit- But just in case you really need it.. Here you go.

Application	Type of Material	GM Part Number	Canadian Part Number

Differential Carrier Assembly Case Mating Surfaces	Sealant	GM P/N 1052942	Canadian P/N 10953466 or equivalent
Electric Motor Actuator	Sealant	GM P/N 12346004 or equivalent	Canadian P/N 10953480 or equivalent
Front Drive Axle	Lubricant	Synthetic Gear Oil GM P/N 88900401 (GM Spec 9986115)	Canadian P/N 89021678
Front Drive Axle Inner Shaft Housing to Differential Carrier Assembly	Sealant	GM P/N 1052942 (Canadian P/N 10953466) or equivalent	Canadian P/N 10953466 or equivalent
Pinion Yoke Splines	Sealant	GM P/N 12346004 (Canadian P/N 10953480) or equivalent	Canadian P/N 10953480 or equivalent

Metric	US English
Application	Specifications
Axle Capacities
Front Axle 1000 Series (8.25”)	1.43 liters	1.51 quarts

Application	Type of Material	GM Part Number	Canadian Part Number
Locking Differential Guides	Chassis Lubricant	12377985 or equivalent	88901242 or equivalent
Pinion Gear Bearing Retainer	Sealant	1052943 or equivalent	10953491 or equivalent
Pinion Yoke Splines	Sealant	12346004 or equivalent	10953480 or equivalent
Rear Axle (8.6/9.5/9.76 inch axles)	SAE 75W85 Synthetic Gear Oil	19300457 or equivalent meeting GM Specification 9986375	19300458 or equivalent
Rear Axle (10.5,11.5 inch axles)	SAE 75W90	88900401 or equivalent meeting GM Specification 9986115	89021678 or equivalent
Rear Axle Housing Spindle	SAE 75W90	88900401 or equivalent meeting GM Specification 9986115	89021678 or equivalent
Rear Axle Hub Spindle	SAE 75W90	88900401 or equivalent meeting GM Specification 9986115	89021678 or equivalent
Rear Locking Differential Clutch (friction disc) Disc (8.6/9.5/9.76 inch axles)	SAE 75W85 Synthetic Gear Oil	19300457 or equivalent meeting GM Specification 9986375	19300458 or equivalent
Rear Locking Differential Clutch (friction disc) Disc (10.5/11.5 inch axles)	SAE 75W90	88900401 or equivalent meeting GM Specification 9986115	89021678 or equivalent
Ring Gear	Marking Compound	1052351 or equivalent	10953497 or equivalent
Wheel Bearings	SAE 75W90	88900401 or equivalent meeting GM Specification 9986115	89021678 or equivalent
Wheel Bearing Cups	SAE 75W90	88900401 or equivalent meeting GM Specification 9986115	89021678 or equivalent

Metric	US English
Application	Specifications
Axle Capacities
Rear Axle 1000 Series without RPO AXN (8.6”)	2.03 liters	2.15 quarts
Rear Axle 1000 Series with RPO AXN (9.5” LD)	2.45 liters	2.59 quarts

 

[DaDenaliDude]

My Denali has the G80 differential and I have been running Amsoil SG 75w-90 for 5 yrs and 60k+ miles. No issues.

Good to know. I was going back and forth between Amsoil and Valvoline.

 

[DaDenaliDude]

Here's some intel.. Front then rear axle specs listed.

I look all this data up, walk over to my cabinet of oils and say.. Hmm.. I have enough of this other stuff.. it'll do. Edit- But just in case you really need it.. Here you go.

Application	Type of Material	GM Part Number	Canadian Part Number

Differential Carrier Assembly Case Mating Surfaces	Sealant	GM P/N 1052942	Canadian P/N 10953466 or equivalent
Electric Motor Actuator	Sealant	GM P/N 12346004 or equivalent	Canadian P/N 10953480 or equivalent
Front Drive Axle	Lubricant	Synthetic Gear Oil GM P/N 88900401 (GM Spec 9986115)	Canadian P/N 89021678
Front Drive Axle Inner Shaft Housing to Differential Carrier Assembly	Sealant	GM P/N 1052942 (Canadian P/N 10953466) or equivalent	Canadian P/N 10953466 or equivalent
Pinion Yoke Splines	Sealant	GM P/N 12346004 (Canadian P/N 10953480) or equivalent	Canadian P/N 10953480 or equivalent

Application	Specifications
Metric	US English
Axle Capacities
Front Axle 1000 Series (8.25”)	1.43 liters	1.51 quarts

Application	Type of Material	GM Part Number	Canadian Part Number
Locking Differential Guides	Chassis Lubricant	12377985 or equivalent	88901242 or equivalent
Pinion Gear Bearing Retainer	Sealant	1052943 or equivalent	10953491 or equivalent
Pinion Yoke Splines	Sealant	12346004 or equivalent	10953480 or equivalent
Rear Axle (8.6/9.5/9.76 inch axles)	SAE 75W85 Synthetic Gear Oil	19300457 or equivalent meeting GM Specification 9986375	19300458 or equivalent
Rear Axle (10.5,11.5 inch axles)	SAE 75W90	88900401 or equivalent meeting GM Specification 9986115	89021678 or equivalent
Rear Axle Housing Spindle	SAE 75W90	88900401 or equivalent meeting GM Specification 9986115	89021678 or equivalent
Rear Axle Hub Spindle	SAE 75W90	88900401 or equivalent meeting GM Specification 9986115	89021678 or equivalent
Rear Locking Differential Clutch (friction disc) Disc (8.6/9.5/9.76 inch axles)	SAE 75W85 Synthetic Gear Oil	19300457 or equivalent meeting GM Specification 9986375	19300458 or equivalent
Rear Locking Differential Clutch (friction disc) Disc (10.5/11.5 inch axles)	SAE 75W90	88900401 or equivalent meeting GM Specification 9986115	89021678 or equivalent
Ring Gear	Marking Compound	1052351 or equivalent	10953497 or equivalent
Wheel Bearings	SAE 75W90	88900401 or equivalent meeting GM Specification 9986115	89021678 or equivalent
Wheel Bearing Cups	SAE 75W90	88900401 or equivalent meeting GM Specification 9986115	89021678 or equivalent

Application	Specifications
Metric	US English
Axle Capacities
Rear Axle 1000 Series without RPO AXN (8.6”)	2.03 liters	2.15 quarts
Rear Axle 1000 Series with RPO AXN (9.5” LD)	2.45 liters	2.59 quarts

Thank you for all this information. I took a screenshot of everything and saved it in my files. It’ll come in handy.

 

[Geotrash]

And to confirm, the G80 is a centrifugally activated mechanical locker, not a limited slip, so it does *not* use LSD additive.