C7 bad diff oil

[steveobes]

Hi guys
Recently purchased a 2019 grand sport with only 2.5k
After reading about needing to change the differential oil before the recommended mileage from GM I decided to change it this week at only 2900 miles.
I was shocked at the condition of the oil that came out.
It was also low as well.
Someone I know took his c7 to a well known dealer who just topped his up without draining.
Terrible service imo.

[steveobes]

[C6NL]

That looks terrible, I change the diff oil in my C6 (I know its not a C7) every 4 years. Over time the LS components in the oil degrade, but the oil that drains after 4 years looks almost the same as the oil that goes in, only a slight deviation in Color

Your oil would make me worry about my diff, IMHO flush and change ASAP

[C7_Vette]

C6NL said:

That looks terrible, I change the diff oil in my C6 (I know its not a C7) every 4 years. Over time the LS components in the oil degrade, but the oil that drains after 4 years looks almost the same as the oil that goes in, only a slight deviation in Color

Your oil would make me worry about my diff, IMHO flush and change ASAP

I would recommend a triple flush. C7's have an issue with the diff oil which over time will cause transmission shudder. Got mine done earlier this year.

[Pitre]

With great respect to those who've replied already, you'll get a much wider audience on www.corvetteclub.org.uk

[bobchevy]

C7_Vette said:

I would recommend a triple flush. C7's have an issue with the diff oil which over time will cause transmission shudder. Got mine done earlier this year.

I think you may find its the auto transmission oil that is the problem for the shudder this was finally rectified in mid 2019 with the 3rd generation of oil for the trans.
Although it is wise to have the diff oil changed as well as it comes out looking like a dirty treacle after only a few thousand miles.
I had all my oils changed as preventive maintenance on my 2019 GS my previous Gen6 Camaro had the shudder and a oil change rectified this but that was only the 2nd iteration of the trans oil so unless its been changed to the new specification after I traded it in for the Vette the problem could reoccur.

[bobchevy]

Pitre said:

With great respect to those who've replied already, you'll get a much wider audience on www.corvetteclub.org.uk

Agreed the topic is more detailed there.

[VetTVR]

Thats exactly how my oil looked out of a 2014 C7 Manual 6500 miles...not sure the gunk was so thick on the sump plug