2016 Rear Differential Fluid/Rear Axle Fluid

[Black02Silverado]

On 6/11/2018 at 5:16 PM, 94boosted said:

So to confirm 75/90 Full Syn, API-GL5, no FM of any kind is the correct fluid for both front & rear diffs (including the locker rear diffs?) i.e. a Redline GL-5 Gear Oil 

 

What are the torque specs for the rear diff cover and the drain/fill plugs for the front diff?

 

 

Also on a semi-related note what fluid & quantity should be used for the t-case? And what are the torque specs for the drain & fill bolts? 

Differential, Front 8.25 RG......GL-5
     All TEMPS......80W-90
         SAE 80W-90 Synthetic Gear Lube (AGLQT)
         Severe Gear® 75W-90 (SVGPK)
         Severe Gear® 75W-110 (SVTQT)
Differential, Rear 8.6 RG......GL-5
     All TEMPS......75W-85 [2]
         Severe Gear® 75W-90 (SVGPK)
Differential, Rear 9.5 RG......GL-5
     All TEMPS......75W-85 [2]
         Severe Gear® 75W-90 (SVGPK)
Transfer Case,MP 3023/3024......AF6
         Signature Series Fuel-Efficient Synthetic Automatic Transmission Fluid (ATL) (ATLQT)
         OE Fuel-Efficient Synthetic Automatic Transmission Fluid (OTLQT)
Transfer Case,MP 1625/1626......AF6
         Signature Series Fuel-Efficient Synthetic Automatic Transmission Fluid (ATL) (ATLQT)
         OE Fuel-Efficient Synthetic Automatic Transmission Fluid (OTLQT)
Transfer Case,MP1222, 25, 26......AF6
         Signature Series Fuel-Efficient Synthetic Automatic Transmission Fluid (ATL) (ATLQT)
         OE Fuel-Efficient Synthetic Automatic Transmission Fluid (OTLQT)

 

 

CAPACITIES:

Engine, with filter..........8 quarts [1] Cooling System, Initial Fill..........16.6 quarts Passenger Car & Light Truck Antifreeze & Coolant AMSOIL Antifreeze and Engine Coolant Automatic Transmission, 6L80 Initial Fill..........6 quarts Automatic Transmission, Total Fill    6 speed LD 6L80..........12.2 quarts    6 speed W/ HD Cool 6L80..........12.4 quarts Differential, 8.25 RingGear Front..........3 pints Differential, 8.6 RingGear Rear..........4.2 pints Differential, 9.5 RingGear Rear..........5.1 pints Transfer Case, MP 3023/3024..........3.2 pints Transfer Case, MP 1625/1626..........3.2 pints Transfer Case, MP1222, 25, 26..........3.2 pints [1] After refill check oil level.

 

TORQUES:    Oil Drain Plug.....18 ft/lbs    Transfer Case      Fill Plug 13 ft/lbs      Drain Plug 13 ft/lb

Edited August 26, 2018 by Black02Silverado

[Gearhead1000]

I bought this kit to measure the diff temp on my truck. I am going to run it for baseline readings. Later I am going to install an aftermarket cover from B&M. The pod was on line at amazon. I am going to pull my rig to BC and I will now be able to see what is happening back there. And I want to see if the new cover makes a difference. 

[mongoose71]

I'm planning to change both of my differentials and my transfer case fluids soon.  My truck is a 2014 5.3 Denali with 73 K miles.  Should I be concerned swapping to synthetics with this many miles.  I've heard that gaskets are more prone to leak after going from dino oil to synthetics on vehicles with higher miles.

 

Any advice on oil types and brands would be appreciated as well.

[2018GMC]

10 hours ago, mongoose71 said:

I'm planning to change both of my differentials and my transfer case fluids soon.  My truck is a 2014 5.3 Denali with 73 K miles.  Should I be concerned swapping to synthetics with this many miles.  I've heard that gaskets are more prone to leak after going from dino oil to synthetics on vehicles with higher miles.

 

Any advice on oil types and brands would be appreciated as well.

Pretty sure the oem gear oils are synthetic blend or full synthetic. 

[2018GMC]

On 9/24/2018 at 8:43 PM, Gearhead1000 said:

I bought this kit to measure the diff temp on my truck. I am going to run it for baseline readings. Later I am going to install an aftermarket cover from B&M. The pod was on line at amazon. I am going to pull my rig to BC and I will now be able to see what is happening back there. And I want to see if the new cover makes a difference. 

What temps have you observed?

 

FYI Banks engineering is testing aftermarket diff covers. The results so far point to the stock cover being superior to some of the aftermarket. 

 

 

Edited October 17, 2018 by 2009GMC

[Gearhead1000]

I towed a 71 duster 250 miles a week ago and saw 125 deg f and out side temp was about 28 dec f. Pulling I figure 5500-6000lbs. I am watching the banks testing closely. Very interesting what Gale has discovered so far. The idea of the fluid hitting the squared corners of the diff cover causes more heat and less fluid being carried up and over to lube the pinion and bearings makes sense to me. Fortunately the B&M cover I bought has curves similar to the stock cover and adds strength to the differental itself. 

The place I installed the temp sensor on the stock cover is above the fluid level stopped and is probably in the coolest fluid area(was the easiest place to install) but it is right in the flow of fluid while running. 

[Black02Silverado]

On 10/16/2018 at 12:23 PM, mongoose71 said:

I'm planning to change both of my differentials and my transfer case fluids soon.  My truck is a 2014 5.3 Denali with 73 K miles.  Should I be concerned swapping to synthetics with this many miles.  I've heard that gaskets are more prone to leak after going from dino oil to synthetics on vehicles with higher miles.

 

Any advice on oil types and brands would be appreciated as well.

No issues with changing out the fluids and leaks.  The gear oil now in your truck is synthetic. 

 

Going with a brand name synthetic is a good choice.  Mobil 1, Redline or AMSOIL Severe Gear® 75W-90

 

It now comes in this nice squeeze pack.  Makes oil changes on diffs so much easier.

 

Anyone interested in Severe Gear send me a PM and I can get you a quote delivered to your door.

 

 

Edited October 19, 2018 by Black02Silverado
added image

[TXGREEK]

I'm planning to change both of my differentials and my transfer case fluids soon.  My truck is a 2014 5.3 Denali with 73 K miles.  Should I be concerned swapping to synthetics with this many miles.  I've heard that gaskets are more prone to leak after going from dino oil to synthetics on vehicles with higher miles.
 
Any advice on oil types and brands would be appreciated as well.

Absolutely not, pop it off, drain, spray with cleaner, throw in your “new” cover and refill with Amsoil severe gear.

I switched diff covers to a G2 and extremely easy to service now.


Sent from above

[TXGREEK]

I towed a 71 duster 250 miles a week ago and saw 125 deg f and out side temp was about 28 dec f. Pulling I figure 5500-6000lbs. I am watching the banks testing closely. Very interesting what Gale has discovered so far. The idea of the fluid hitting the squared corners of the diff cover causes more heat and less fluid being carried up and over to lube the pinion and bearings makes sense to me. Fortunately the B&M cover I bought has curves similar to the stock cover and adds strength to the differental itself. 
The place I installed the temp sensor on the stock cover is above the fluid level stopped and is probably in the coolest fluid area(was the easiest place to install) but it is right in the flow of fluid while running. 

Aftermarket is the way to go especially with milled fins and large magnets.


Sent from above

[300 Blackout]

I'm planning to change both of my differentials and my transfer case fluids soon.  My truck is a 2014 5.3 Denali with 73 K miles.  Should I be concerned swapping to synthetics with this many miles.  I've heard that gaskets are more prone to leak after going from dino oil to synthetics on vehicles with higher miles.
 
Any advice on oil types and brands would be appreciated as well.

I highly recommend when you make a new gasket to use Permatex Right Stuff instant gasket maker in either black or grey. The benefit is you can apply it easily in one continuous bead, install the cover and torque your bolts to the torque spec immediately without waiting an hour. You can also fill it with fluid right away rather than waiting 24 hours.

I think synthetics leaking in older vehicles has more to do with the gasket than anything else. When you do pop the cover, be sure to clean the magnet just under the ring gear. Also remember to cover the differential and gears before scraping the left over gasket material off of the axle. I took a picture of my differential then made a gasket, sealed up the rear end and began the waiting game. Went into my house and looked at my picture. Saw a piece of gasket that fell into the locker. It drove me nuts so I ended up removing the cover again to clean the locker and went through the gasketing process again. Not hard to do, but definitely something you want to do right.

I went with Amsoil Severe Gear 75W-90 and a PML cover. So far I’m very pleased.

[Druder]

9 hours ago, 300 Blackout said:

I highly recommend when you make a new gasket to use Permatex Right Stuff instant gasket maker in either black or grey. The benefit is you can apply it easily in one continuous bead, install the cover and torque your bolts to the torque spec immediately without waiting an hour. You can also fill it with fluid right away rather than waiting 24 hours.

I think synthetics leaking in older vehicles has more to do with the gasket than anything else. When you do pop the cover, be sure to clean the magnet just under the ring gear. Also remember to cover the differential and gears before scraping the left over gasket material off of the axle. I took a picture of my differential then made a gasket, sealed up the rear end and began the waiting game. Went into my house and looked at my picture. Saw a piece of gasket that fell into the locker. It drove me nuts so I ended up removing the cover again to clean the locker and went through the gasketing process again. Not hard to do, but definitely something you want to do right.

I went with Amsoil Severe Gear 75W-90 and a PML cover. So far I’m very pleased.

I was under the impression that our factory gaskets were a quality piece and reusable, is this not the case? My experience is that rtv makes a mess for the next time and to only use it as a last resort.

[300 Blackout]

I was under the impression that our factory gaskets were a quality piece and reusable, is this not the case? My experience is that rtv makes a mess for the next time and to only use it as a last resort.

Many people use RTV in addition to the factory gasket. My factory gasket was rusted on the edges, I didn’t want to chance having an issue so I tossed it. The Right Stuff RTV was less messy than other RTV that I used. If your factory gasket is in good condition then it can be reused. If you also choose to use RTV then maybe you’ll have a better experience with the above product.

Regarding gear oil, the following link is to a study performed at the request of Amsoil. The methodology of the study appears to be solid and was the reason I chose Severe Gear over some of the other quality gear oils. https://www.lastgreatroadtrip.com/wp-content/uploads/2010/11/gear-oil-comparison.pdf

[Druder]

6 hours ago, 300 Blackout said:

Many people use RTV in addition to the factory gasket. My factory gasket was rusted on the edges, I didn’t want to chance having an issue so I tossed it. The Right Stuff RTV was less messy than other RTV that I used. If your factory gasket is in good condition then it can be reused. If you also choose to use RTV then maybe you’ll have a better experience with the above product.

Regarding gear oil, the following link is to a study performed at the request of Amsoil. The methodology of the study appears to be solid and was the reason I chose Severe Gear over some of the other quality gear oils. https://www.lastgreatroadtrip.com/wp-content/uploads/2010/11/gear-oil-comparison.pdf

Thanks for the followup, that's good info. I actually bought the severe gear a few weeks ago and haven't gotten around to changing it out yet. This weekend may prove to be the perfect opportunity.

[dp454so]

Hey guys,

 

Great thread here.  for my front/rear diffs, I ordered Royal Purple 75w90 based off of the recommendations here that the 75/85 is just for mileage and I'd rather have the protection of a heavier lubricant and am looking to reduce the trans slap common with the 8speed.  '16 LTZ 6.2 has 108k and I'm curious what condition the oils is going to be.   https://shop.advanceautoparts.com/p/royal-purple-max-gear-synthetic-gear-lube-oil-75w90-01300/7070082-P?utm_source=ET&utm_medium=TRANS&utm_term=TRNSCT&utm_campaign=20211017_A_EC_TX_ORDCON &utm_content=ITEM

 

Considering also changing gaskets on the rear diff out of caution since I am pretty high mileage.

 

How are the aftermarket rear diff covers working for those that are running them?  Make sense that extra fluid would help with temps and performance and maybe longevity of the diff.  Don't know if it's worth the several hundred bucks for a part that only offers marginal improvement.

[Black02Silverado]

47 minutes ago, dp454so said:

Hey guys,

 

Great thread here.  for my front/rear diffs, I ordered Royal Purple 75w90 based off of the recommendations here that the 75/85 is just for mileage and I'd rather have the protection of a heavier lubricant and am looking to reduce the trans slap common with the 8speed.  '16 LTZ 6.2 has 108k and I'm curious what condition the oils is going to be.   https://shop.advanceautoparts.com/p/royal-purple-max-gear-synthetic-gear-lube-oil-75w90-01300/7070082-P?utm_source=ET&utm_medium=TRANS&utm_term=TRNSCT&utm_campaign=20211017_A_EC_TX_ORDCON &utm_content=ITEM

 

Considering also changing gaskets on the rear diff out of caution since I am pretty high mileage.

 

How are the aftermarket rear diff covers working for those that are running them?  Make sense that extra fluid would help with temps and performance and maybe longevity of the diff.  Don't know if it's worth the several hundred bucks for a part that only offers marginal improvement.

No need to get a new gasket.  They are rubber with metal in between. 

 

Aftermarket differential covers to me are really not needed unless you tow/haul daily. The benefits are just not there to justify the cost.  They look nice and add extra fluid, but considering rear differential failures are pretty much non existent.  It is personal preference for the most part. Using a quality synthetic and changing it out every 50k or so is best.  Most never touch the rear differential fluid.

 

I change mine out after 500 miles to get the wear in materials out and then at 100k miles, using AMSOIL's Severe Gear.  My UOA on the fluid shows that the fluid is still good and wear metals are well within limits.