Fluids

[wwhorton]

I am wanting to start changing the fluids in my truck since its so much more expensive for the dealership to do it. What fluids do y'all recommend for oil, transfer case, transmission, etc.?

[Supreme Pizza]

Using all OEM fluids is usually the best option. 

 

If its been over 100K miles since your last transmission service, you may want to skip that to prevent problems. 

 

After filling the rear diff, let it sit for 10 minutes and check the level again before plugging the fill hole.

[Colossus]

The OEM fluids, or rather the stuff you buy at the stealership parts counter is essentially stuff made by the manufacturers that are sold at the regular parts stores.  Good rule of thumb is to ensure that the fluid you buy at the parts stores meets or exceeds the specs called for in the owners manual.  Which almost all of them will.  I personally like to get my stuff from NAPA, I've found them to have the best quality of parts as well as the most knowledgeable parts counter folks. 

 

[Supreme Pizza]

 

 

      To clarify what I meant: 

 

 

32 minutes ago, Colossus said:

Good rule of thumb is to ensure that the fluid you buy at the parts stores meets or exceeds the specs called for in the owners manual.

 

 

[seamus2154]

Mobile 1 is dexos approved and a great choice. I have swapped out the fluid in all 4 of my trucks in this platform. All with less than 10k on them and the diff fluid looked horrible. I bought them new and no abuse. GM's fluid is expensive and is for fuel mileage. Doesnt hold up well. I only run Amsoil Sever gear 75/90. Great stuff with good analysis reports over many years for me. 

[Black02Silverado]

Any of the dexos rated fluids you find on the Auto parts shelf or Walmart will work for your engine.

 

Dexron VI for your transmission, again what you will find at the auto parts store.  Mobil 1, Royal Purple, AMSOIL that are Dexron VI will work well.

 

Transfer case takes the same as your transmission.

 

Gear oil for the front and rear differentials again, I would go with a full synthetic 75w-90 like Mobil 1, Royal Purple or AMSOIL Severe Gear.  No need for the super expensive grape smelling GM fluid.

[Dr Awesome]

When you ask about the best oil, you will get 10 different opinions from 8 people!   But for me I use Liqui Moly full synthetic for the diffs and transfer case.  Liqui Moly doesn't have a Dexos1 Gen 2 stamped engine oil right now, so the oil I have is Mobil 1 from the dealership (free changes) until I start doing my own, which I will probably switch to another actual full synthetic.  I was thinking Amsoil, but they don't have the Dexron1 Gen 2 stamp on it, so I'm not sure yet.  The transmission in the 8 speed uses Mobil 1 HP fluid, which is GMs standard for that.  I think the 6 speed is still listed as Dexron VI, so if I had that I would swap it out with Liqui Moly around 30k.  Or I think some have used the M1 HP fluid in there and had good results with the clunky shifts (don't quote me on that, though, I only know about the 8 speed).

 

Fully synthetic is better for protection, longevity, etc.  In the USA you can put full synthetic on the box even if it is blended, but in Europe and many other countries they don't allow it.  That is one reason I buy Liqui Moly, which is made in Germany and is truly fully synthetic, and I've had very good performance in my past vehicles.

 

In the end I think the important thing is that you do the maintenance on time, and less about what product you use.  There's always that guy putting in walmart bottom shelf oil in every 15k and not having any issues, but you won't see me taking that chance!

[Z45]

The best 100% synthetic oil in the world is made 2.5 hrs north of you in  Duluth-Superior.   No need to buy imported stuff.  

[Dr Awesome]

23 hours ago, elcamino said:

The best 100% synthetic oil in the world is made 2.5 hrs north of you in  Duluth-Superior.   No need to buy imported stuff.  

Are you talking about Amsoil?  They make great stuff, and I would use it in the truck, but they didn't get the approvals for Dexos1 Gen 2 (even though it would probably exceed it easily, I think they just didn't pay for it).  If something went wrong in the engine, that would be ammo for GM to not approve repairs under warranty.  Again, that's really unlikely, but until I'm out of warranty I will wait to put that in the truck.

[Roscopcoletrain]

10 hours ago, Dr Awesome said:

Are you talking about Amsoil?  They make great stuff, and I would use it in the truck, but they didn't get the approvals for Dexos1 Gen 2 (even though it would probably exceed it easily, I think they just didn't pay for it).  If something went wrong in the engine, that would be ammo for GM to not approve repairs under warranty.  Again, that's really unlikely, but until I'm out of warranty I will wait to put that in the truck.

 

https://www.amsoil.com/shop/by-product/motor-oil/gasoline/sae-0w-20-signature-series-100-percent-synthetic-motor-oil/?code=ASMQT-EA

Quote

Original equipment manufacturers (OEMs) like GM* have addressed the issue by designing tests to determine a motor oil’s ability to prevent LSPI. Signature Series Synthetic Motor Oil achieved 100 percent protection against LSPI1 in the engine test required by the GM dexos1 Gen 2 specification - zero occurrences were recorded throughout five consecutive tests

.

[Kubs]

10 hours ago, Dr Awesome said:

Are you talking about Amsoil?  They make great stuff, and I would use it in the truck, but they didn't get the approvals for Dexos1 Gen 2 (even though it would probably exceed it easily, I think they just didn't pay for it).  If something went wrong in the engine, that would be ammo for GM to not approve repairs under warranty.  Again, that's really unlikely, but until I'm out of warranty I will wait to put that in the truck.

The owner's manual calls for Dexos1 or equivalent.  This means AMSOIL should not be a warranty voiding oil.  AMSOIL does not carry a Dexos1 label because they did not pay GM for the approval, but it far exceeds the requirement.  Also, if you use AMSOIL and the Dealer does not warranty the fix that was proven to be the fault of the oil, AMSOIL will pick up the bill.

[Black02Silverado]

If you are going to do 5k oil changes or follow the OLM which is capped at 7,500 miles then the AMSOIL OE would work well.

 

AMSOIL OE 0w-20

 

It you want to extend your oil changes to 10k or higher then go with the Signature Series.

 

AMSOIL Signature Series 0w-20

 

AMSOIL has a Preferred Customer program, it is similar to Sam's club where you pay an annual fee and then you get everything at the wholesale price which you can take off about 25% off the prices listed in these links.  Plus all shipping over $100 is free.   Also if you live close to a distribution center then you can pick it up there and safe shipping on small orders or get it the same day you want it.

 

If you are interested in becoming a Preferred Customer  Send me a PM  I'll get you set up and provide the GM-Trucks discount as well to the PC program.