I was changing rear gear fluid and found that GM and Delco are not real clear on their oils and the web just muddies the water even more.

I contacted Scoggin and Dickey Chevy the performance dealer out of TX. They are GM's prime performance dealer and I had a contact there that could fill me in.

The 10-4016 gear oil is good in a C5 and all other year Corvettes. It is heavy duty for heat and high speed. It does need at least one LS additive bottle and in some cases two if you still have noise after one.

Many are also using 10-4034 and it is ok too but really is intended for 2007 and later cars. Also it is a multi purposes oil for even transfer cases etc. It too will work in other cars. GM also requires this lube for warranty work and repair work. Note even with the LS additive many times a second bottle may need to be added if their are still snap and pop noises when turning.

So the 10-4016 is the primary one to use in the C5 but the 10-4034 will still work. The key for noise is to add a second bottle of LS modifier if you still have noise after a change.

Confusing yes but I hope this helps. It comes from a very reliable source.

FYI 10-4108 was not recommended as it did not meet the requirements as specified by GM for oil in a Corvette. I have seen some Corvette places offer this and found this interesting.

 

You know - I've been getting popping noises at track day and someone mentioned it could be diff - perhaps another bottle of LS will help

 

Yes that is the first thing to try. Different materials and different tensions can require more LS modifier. All are not the same.

 

Any reputable brand 75/90 synthetic oil with LS additives will do the job

 

Not really. Most May but you need to read the label and you need to understand the specifications of the vehicle.

10-4108 does not meet the spec for the Corvette according to them.

If one fit all they would not make so many different 75w90 oils,

You may get away with a non spec type because you only street drive but some oils are made for higher pressures and temps. If you track time the wrong fluid could fail.

What saves many is they never reach the limits of their cars.

 

Years ago, my parents' Oldsmobile (limited-slip, of course) was making popping noises when going slowly around sharp turns, e.g., pulling out of the driveway. Changing the diff fluid solved the problem instantly. It never made another sound after that.

 

Yes a common fix for either bad fluid or not enough additive.

 

I bought 2 bottles of the 10-4034 about 5 years/40,000 miles ago. At any rate, I changed the fluid at 100,000 miles, same time I did the A4 tranny fluid & filter. It didn't take both bottles, more like 1-1/2, maybe 1-3/4 bottles. There's never been any clicking or any diff issues, and car is 23 years old and @140,000 miles. Worked for me. I used an old Eagle brand steel hand pump oil can with nozzle to fill, until the fluid started coming out the bottom of the threads. Had to refill the hand pump can several times. There are better ways to fill the pumpkin, for sure. But I didnt want to spend the $$ for something I already can use. Yes-I'm a cheap old bastard!!!

 

The 1034 will work but it is intended more for the 07 and later cars. Also warranty work. Scoggin and Dickey gave just what GM recommended.

Think of many oils as non speed rated tires. You may get away with them on the Vette because you never reach the level of what the car can do. Many get away with non recommended oils because they again never drive the car to the limits. GM recomends tires and oils fror the limits of the car to make sure there is no chance anyone will have an issue. If you use less and it fails then it is on you liability wise.

 

GM, like all OEM fluids, are bought from one of the big suppliers and private labelled. As an example, the GM Synchromesh fluid, spec'd for the New Venture manual trannies in some light trucks, was a Pennzoil product and sold by them under their brand for rather less than buying it from a GM dealer. Texaco is noted in various places online as a source for some GM axle fluids. And you better believe Exxon Mobil is in there too.

When we had our turbo Subie, I ran Mobil Delvac 75-90 in the transaxle. I figured if it was good enough for the MT Porsche 911 family, including competition use, it was good enough for me.

 

I don't track my car, so this information may be inconsequential, but I've been using Red LIne's gear oil in my C-5 for the last 22 years, with no issues whatsoever.

 

When I changed my diff fluid, I called the Chevy dealer to ask what diff lube I should run. He told me the old fluid had been superseded with a new part number, and the new number was 10-4034. IDK where you got the info that the 10-4034 was intended for '07-up cars, but lets say you're correct. Any '07 C6 would have more power than a stock 2000 C5. So if it works with a higher output C6, why wouldnt it work fine for a lesser powered C5? Also, my C5 isn't stock. It has had a 600+HP LS7 in it for many years. I've made over 50 1/4 mile dragstrip runs, and have 140,000 miles on the diff. I've had no issues, so far.....

 

Best to just use what the mfg says.

it used to be 2 different oils did it all but so many of these cars today require specific oil for specific applications.

Just using what you think may work at times but only once being wrong can get expensive,

I expect the mfg knows more than any of us.

 

Look I contacted Scoggin and Dicky Chevy from TX. They are one of the main distributors of GM Performance and Racing parts.

They supplied me with the info from what GM recommends.

GM knows more about this than anyone here. Sure some may use oils that work but they still may not be what is recommended.

Use and do what ever you like as I just supplied what GM recommended so I am not going to argue about this.

I think, I use, I know and I feel is not what GM states. They gave numbers and what to use.

GM and a Delco have been very confusing with their reconditions since the bail out. I work in the performance industry and contacted people I know in the GM Racing to fix our web site as we said one oil was for posi but then we state it had no additive for LS.

I just tried to clear the air. So do what ever you like.

 

Thanks for the info.

Moved to C5 Tech.

 

Im not trying to argue with you, my friend. But, as I said, I got the 10-4034 from a dealer. Scoggin Dickey is also a dealer. GM changes recommendations from time to time, like .060" plug gaps are now .040". Wiggle tests for worn valve guides was recommended as the go to test for bad guides for most of the 20th century. But when LS7s started wearing out guides in under 20,000 miles, GM flipped, and now says the wiggle test is not accurate. So, which GM recommendation is correct? The one you got, or the one I got? Who knows. I do appreciate your information, but as of this moment, I truly don't know whose recommendation is correct, since both are GM recommendations. I like Scoggin Dickey. Very knowledgeable people there. Like Kurt Urban, who is running a lot of their crate engine program, or so I've been told.....

 

How many quarts in the pumpkin?

 

Read my post in the thread. I used 1-1/2 to 1-3/4 bottles. I think they're 16oz. each....

 

I have a working relationship with Scoggin. via GM Performance. They are my reliable source of info on GM products being they are very well connected to GM racing and performance.

I copied and pasted their reply here. Take it for what it is. I just was passing along reliable info I was given to help here not start a debate. This started as I was updating my web for work as it was not clear at all to my staff let along the customers.

Note where it states this meets GM Specification 9986115 which is the current spec given by GM.

Scoggin replay to me asking for what to use in my 2002 CorvetteAccessing the GM Service System and for the 2002 Corvette it specifies the following - - -

SAE 75W-90 Synthetic Axle Lubricant, meeting GM Specification 9986115. With a complete drain and refill add 118 ml (4 oz) of Limited-Slip Differential Lubricant Additive GM P/N 1052358 (Canadian P/N 992694) or equivalent.

10-4016 is a 75W-90 Synthetic Gear Lube that meets this requirement - - this is known as a Heavy Duty Extreme GL5 Lubricant. Specifically designed for high-temp applications during extended high-speed operation or heavy towing applications.

10-4108 is a Standard Duty 75W-90 Gear Lube and does not meet that requirement as specified by GM.

I then asked about the Additives for 10-4016 And here was the reply.

Yes, you need to add the LS Additive.

The additive is specifically designed for the LS Differentials. None of the GM Gear Oils have this “friction-modifier” that is contained in the LS Additive.

Interesting to note that the late model LS Diffs in GM vehicles are very good at the function of applying torque to both wheels. At low speeds they will tend to lock like a “spool” in a race car causing all kinds of sounds and wheel hops. The Diff will make a very loud “pop” in these cases. This additive will solve that issue.

This tends to happen when people decide it is time to change the oil in the rear end of the vehicle and they do not add the LS Additive back in as part of the lubrication. And sometimes it requires two bottles!

I then ask specific about the 10-4034 and here was the reply.

10-4034 was specifically intended for 2007 and later applications, also it was intended as a multi-purpose gear lube that included transfer cases, manual transmissions and the read end. The Official Description for this Lube indicates that it has the “friction-modifier” already in the lube - - so you could read my last statement as incorrect.

It also has the “Dexron” designation which is a unique blend of their own.

You can advertise it as having the “Friction-Modifier” already in the lube.

However, we have found that when most customers use this lube when doing a complete rebuild or oil change, in most cases it still requires a minimum of one bottle of LS Additive to prevent that problem I have described.

The majority of our sales for this Part Number are solely for Repair Orders in our shop when it relates to GM Warranty or the install of new components in a Customer Pay repair and GM requires this lube to be on the Repair Order for Warranty coverage.

That is what was offered as advice. I know the gentleman that stated this and he is one of the most reliable people on GM and GM performance vehicles. If you accept his advice great if not that is up to you. As I said I just tried to clear up a very cloudy area on this topic as even our own web site was not clear to my staff let alone the customers.

10- 4034 may work fine but it is not the primary recommendation from GM based on the GM Specification 9986115.

Again this is not for debate. I just passed along the info I was given.

 

1 and 3/4 to fill and you may need 4 oz to 8 oz of LS additive if not already included in the oil you chose.