[Retro69]

Originally Posted by Mr. Wyndham

They just don't want you to set cruise control on your way home from the dealer.

That’s funny ! I can’t imagine even thinking about cruise control on her maiden voyage!


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[blk04sr]

So it looks like most people change the engine oil at 500 and 1500. Sounds like its hit or miss on the diff fluid, do you think it will be fine changing the diff fluid at 1500?

[ZED SLED]

Mine went in storage at 1700. When I get it back out in April I plan to change it. For my '13 I just bought OEM diff oil off Amazon and paid my dealer $45 to change it. I'll do the same on this one. Yeah I know, why pay someone, blah, blah, blah?

[kwav8r]

Originally Posted by blk04sr

So it looks like most people change the engine oil at 500 and 1500. Sounds like its hit or miss on the diff fluid, do you think it will be fine changing the diff fluid at 1500?

Yes.

[Mr. Wyndham]

Originally Posted by blk04sr

...Sounds like its hit or miss on the diff fluid, do you think it will be fine changing the diff fluid at 1500?

Yes. Here's what the owners manual says:

p 199. Axles must have [1,500 mi] before being used in track driving. The rear axle fluid temperatures may be higher than when driving in severe conditions. Drain and refill with new fluid after the first racing or competitive driving event, and then after every 24 hours of racing or competitive driving.

p 210. Should the vehicle be used for racing or competitive driving (after break-in), the rear axle lubricant must be replaced beforehand.

p 333. Replace rear axle fluid, if equipped with limited-slip differential. At 45,000 mi, 90,000 mi, 135,000 mi

So...what I interpret this to mean is; after break-in @ 1500 miles...change the fluid. Then, change the fluid AGAIN after the first track day, and after that every 24hrs of racing or 45,000 miles of regular service.

[Elite Engineering]

Here are GM's instructions (from LS new engines, but still the same for LT):





And the rear diff should be done by 1000 miles!!!! BMWD is correct. This is really the only other portion of the drive-train that needs to "break in" as the gears mesh in and clutches/steels shed material in that initial few hundred miles. Leaving that in greatly contributes to wear.


I would never leave the initial oil fill in longer than a few hundred mile. As the GM instructions show, drain immediately after ring seating.

[ReefBlueCoupe]

This is one of those topics that, no matter what someone does as far as breaking in or not breaking in, any damage or longevity because of doing it one way or the other is impossible to prove, and so people will choose one method vs the other because they "believe in it" or "that's wut muh daddy did" or "drive it like u stole it rite off the lot lol " or the other extreme of changing the oil 5 times before it hits 1k miles and follow the owner's manual to the letter.

This type of thread has been posted tens of thousands of times on message boards, and always has the same answers.

[unavailablezl1]

Originally Posted by hawk02

I followed the break-in outlined in the owners manual. There were a couple times I wasn't paying attention and went above 80 for a brief moment. Please don't tell anyone.

The hardest part of the process for me was driving at a variable speed on the freeway. That's a real PITA.

As far as oil changes, I did the first at 500 miles, the second at 1500, and now I'm on an every 3000-5000 mile interval. I also had the rear diff fluid changed out at 1500 miles.

I pretty much followed the same procedure with my 2013 ZL1.

It took me from the middle of November 2016 to the end of April 2017 to reach that magic 1500 miles. As soon as I hit 1501, I headed to Mexico for a little fun.

I love Mexico!!!!

[Stephen12ZL1]

if you have a new engine in a car above 1500 miles, follow elite engineering’s GM crate motor guide. As stated, the majority of the 1500 mile break in has to do with other components. There is an opinion for everything but I believe what GM has printed in black and white.

[msawyer110]

Anyone that says drive it like you stole it is a moron.

When a proper break-in is executed, the ring will be riding on a film of oil on the bearing loading surface of the cylinder wall while the valleys in the cross-hatched surface provide proper oil retention. Neither the ring, nor the cylinder wall can experience too little or too much wear for a proper break-in. The process of trying to establish this proper wear profile is sometimes referred to as setting or seating the rings. An ideal setting or seating between the rings and the cylinder results in minimal leakage past the rings, minimal oil consumption, reduced cylinder wear, reduced ring wear and exceptional heat transfer between the rings and the cylinder wall.

[ReefBlueCoupe]

Originally Posted by msawyer110

Anyone that says drive it like you stole it is a moron.

When a proper break-in is executed, the ring will be riding on a film of oil on the bearing loading surface of the cylinder wall while the valleys in the cross-hatched surface provide proper oil retention. Neither the ring, nor the cylinder wall can experience too little or too much wear for a proper break-in. The process of trying to establish this proper wear profile is sometimes referred to as setting or seating the rings. An ideal setting or seating between the rings and the cylinder results in minimal leakage past the rings, minimal oil consumption, reduced cylinder wear, reduced ring wear and exceptional heat transfer between the rings and the cylinder wall.

Naw man, that's not the way daddy dun it, and he beelt plenty them tree fiddy Chebbys and knows waaaaay more than them intellectuals up air in DEEETROYT

[seanblurr]

I swapped engine oil to 15w50 and diff at around 1000 miles and started to drive normally at that point. Diff swapped again after first track event. Will be running 15w50 Mobile 1 the majority of the time in this car.

[Suthnfried]

Found this thread which has been idle for a while but hoping that someone can help clarify some of the previous comments?


According to https://my.chevrolet.com/content/dam...tion-guide.pdf, "Avoid cruise control or driving at one constant speed"


I'm picking my ZL1 up from the dealer and have about 1000 miles to get home. What is the best way to avoid this 'driving at one constant speed' thing and still make it down the road? Any suggestions?


Should I drive it for an hour and then shut it down to get fully cold until I reach 500?

[Vigilante375]

Originally Posted by Suthnfried

Found this thread which has been idle for a while but hoping that someone can help clarify some of the previous comments?


According to https://my.chevrolet.com/content/dam...tion-guide.pdf, "Avoid cruise control or driving at one constant speed"


I'm picking my ZL1 up from the dealer and have about 1000 miles to get home. What is the best way to avoid this 'driving at one constant speed' thing and still make it down the road? Any suggestions?


Should I drive it for an hour and then shut it down to get fully cold until I reach 500?

Every vehicle follows the same procedure. Don't drive at a constant speed, don't brake too hard, don't drive at a constant RPM or go above certain RPMs, etc. I even think there might even be a thing that says to not drive for a prolong time.

There will be those that say drive it like you want and other that say follow the break in procedure.

The best way to avoid driving at a constant speed/RPM it to not use your cruise and do like we did before cruise before cruise was available....control your speed/RPM with your right foot.

Speed isn't really relative in a break in procedure that says don't drive at a constant speed because it's all about the RPMs. As in, if a vehicle's RPMs are the same at 60 mph as they are at 40 mph.

Just drive with common sense and change your speed/RPM every so often. You can use your cruise and use the + or - to adjust your speed but it'll be easy to forget that it's on.