[Greg83]

I know this has been discussed but I can’t find a GOOD answer. I know most guys use 10-4034 dif fluid in there ZL1 but that doesn’t seem to be synthetic. I just left my dealer and after using my vin to look up the correct fluid they recommend using the synthetic 10-4016 and adding the friction modifier. He seemed to think you pore in 1 friction modifier and then fill the dif with the synthetic 10-4016 until it’s full. What are you guys using and if using the synthetic 10-4016, are you just adding the one 4oz bottle? Thanks!!

[Iconic]

If we had this exact thread and only parts guys at dealers could reply, the thread would be the same quagmire as any other. I did my SS 1LE with 10-4034 75W-90 GL-5.

It took me hours of rrsearch to pick this one because every thread on any site is filled with various part number. I called 2 local dealer and got 2 different parts number. The f***ing owners manual doesn't even specify. Its f**** maddening

[Vigilante375]

There is a locked thread at the top of the page for the 500/1500 mile service and beyond. It had all the part numbers you need in there.

Everyone who uses the OEM fluid uses the 10-4034 part number and we have had no issues.

I've seen many threads on here where the parts department at the dealership comes up with a part number that's not correct. Even after entering the VIN.

Do what you think but the 10-4034 hasn't given me or any other owners any issues. That's also for those that road course their cars.

[clg82]

https://www.camaro6.com/forums/showthread.php?t=565216

Ordered 2 quarts on amazon yesterday of 10-4034 and should be here tomorrow. After multiple track days in high heat, I always change it with that particular fluid and have had zero issues.

[Greg83]

Originally Posted by Iconic

If we had this exact thread and only parts guys at dealers could reply, the thread would be the same quagmire as any other. I did my SS 1LE with 10-4034 75W-90 GL-5.

It took me hours of rrsearch to pick this one because every thread on any site is filled with various part number. I called 2 local dealer and got 2 different parts number. The f***ing owners manual doesn't even specify. Its f**** maddening

Glad to know it’s not just me who is frustrated with this. Part of me say to use the 10-4034 that everyone has been using for so long. Another part of me says to use the synthetic because I assume it’s better and because it’s what the dealer recommends and what the dealer is trying to sell me… then if there is a problem in the future I have my receipt from the dealer showing my vin and what they sold me. What a mess!!! In the end both are probably fine and we are worrying over nothing but I don’t ever want to find out what it costs to replace an E-Dif in these cars… lol

[Greg83]

Has anyone used the synthetic 10-4016 and added the friction modifier?

[DangerZL1]

Use the 10-4034 fluid. It has the right amount of friction modified in it and is the factory fill. I remember when the ZL1 came out in 2012 owners were trying other brands of fluid thinking the GM fluid was inferior. I’ve got two quarts of the 10-4034 ready to be used in my fluid change this weekend

[Vigilante375]

Originally Posted by Greg83

Glad to know it’s not just me who is frustrated with this. Part of me say to use the 10-4034 that everyone has been using for so long. Another part of me says to use the synthetic because I assume it’s better and because it’s what the dealer recommends and what the dealer is trying to sell me… then if there is a problem in the future I have my receipt from the dealer showing my vin and what they sold me. What a mess!!! In the end both are probably fine and we are worrying over nothing but I don’t ever want to find out what it costs to replace an E-Dif in these cars… lol

Every vehicle is like this. Go but a top of the line Mercedes or BMW or Ferrari and you won't find anything in the manual about what part number you should use for anything.

I've been looking and can't really find where this is supposed to be use except on the 7th gen ZR1.

[WhiteMale]

I used RP 75-90 Max Synthetic Gear with the addiditive for my ZL1.

https://www.oreillyauto.com/detail/c...0?q=7590&pos=6

[getchapull]

Originally Posted by WhiteMale

I used RP 75-90 Max Synthetic Gear with the addiditive for my ZL1.

https://www.oreillyauto.com/detail/c...0?q=7590&pos=6

This the correct part number.

[CalgaryZL1]

Originally Posted by DangerZL1

Use the 10-4034 fluid. It has the right amount of friction modified in it and is the factory fill. I remember when the ZL1 came out in 2012 owners were trying other brands of fluid thinking the GM fluid was inferior. I’ve got two quarts of the 10-4034 ready to be used in my fluid change this weekend

^^ this!
It doesn’t matter that it’s not synthetic. What matters is you don’t wait 45,000 miles to change it, do it once every few season as your routine maintenance and life will be good.

[FarmerFran]

JTDC!

[CalgaryZL1]

Originally Posted by FarmerFran

JTDC!

Is that the same WWJD? I’ve never been good at figuring out why people can’t just spell out the entire word for what they are trying to say, and we wonder what’s wrong with lazy ass society

[Stephen12ZL1]

use what GM recommends for the rear diff...the synthetic isn't better if it doesn't have the appropriate additive. It is simple to change and you can change it more often with the 88862624. I had a '15 Z/28 which had the rear that required the synthetic you list above. Gear oil isn't like engine oil so the "synthetic has to be better" thing is not a worry at all. Clean gear oil in the diff is the most important so swap it at 500mi & 1500mi when the car is new. After break in follow GM's protocol for track use diff fluid changes or swap it yearly if there is no track use.