Just finished changing diff fluid, I doubt it was done prior. - Page 2

LonghornMM · 05-07-2021, 01:52 PM

My car has just over 1K miles on it. Just ordered 2 quarts of Royal Purple 75W-90 this morning. I'll be changing the rear end oil in a week or so.

Guys, any clearance issues having enough room to get the quart container above the fill hole when refilling the rear end housing? I'm hoping that I won't have to use a pump.

gtfoxy · 05-07-2021, 07:10 PM

Keep in mind the GM fluid comes with the friction additive mixed in. Not sure about the RP stuff, but I’m going with no.

Get a pump. I have a cheap auto parts store one & it is soooo much easier. You can run a long hose up to the diff, cut a short chunk to go in the bottle & be behind the bumper pumping it in.

Capacity is 1.6Qts, so 1Qt- 21.6oz.

LonghornMM · 05-08-2021, 12:53 AM

Quote:

Originally Posted by gtfoxy

Keep in mind the GM fluid comes with the friction additive mixed in. Not sure about the RP stuff, but I’m going with no.

Get a pump. I have a cheap auto parts store one & it is soooo much easier. You can run a long hose up to the diff, cut a short chunk to go in the bottle & be behind the bumper pumping it in.

Capacity is 1.6Qts, so 1Qt- 21.6oz.

The Royal Purple fluid does come with the friction modifier in it. FYI, according to the GM owners manual, the differential holds 1.2 QT.

gtfoxy · 05-08-2021, 05:29 AM

Quote:

Originally Posted by LonghornMM

The Royal Purple fluid does come with the friction modifier in it. FYI, according to the GM owners manual, the differential holds 1.2 QT.

The dealership printout said 1.6.

KingLT1 · 05-08-2021, 08:17 AM

If you put anything other then GM fluid in the diff plan on it making noise. Now I haven't specifically tried Royal Purple but when I changed my fluid I used Mobile 1, and the diff made noise. Then tried Valvoline, also made noise. Added friction modifier, still made noise. Put AC Delco in it and it went away.

Puddin · 05-08-2021, 08:39 AM

Quote:

Originally Posted by KingLT1

If you put anything other then GM fluid in the diff plan on it making noise. Now I haven't specifically tried Royal Purple but when I changed my fluid I used Mobile 1, and the diff made noise. Then tried Valvoline, also made noise. Added friction modifier, still made noise. Put AC Delco in it and it went away.

I can confirm if you use the Royal Purple it will continue to make noise. The only fluid I've found that keeps the diff quiet is the GM fluid.

LonghornMM · 05-08-2021, 01:32 PM

After considering everything, reading here, articles on different types of oil and talking to a good friend of mine who is a mechanical engineer and car freak who studies up on things like this, I have decided to go with the factory GM differential oil.

Buckwheat · 05-09-2021, 08:47 AM

I just changed mine.
I have a 2021 with 6 miles and never drove it until I changed the rear end oil..
BTW stick with the AC Delco rear end oil.

2SS Capt · 05-09-2021, 04:09 PM

Quote:

Originally Posted by Buckwheat

I just changed mine.
I have a 2021 with 6 miles and never drove it until I changed the rear end oil..
BTW stick with the AC Delco rear end oil.

Why did you change the diff fluid with only 6 miles on it?

Buckwheat · 05-09-2021, 05:24 PM

Don’t trust Factory Line Union Workers.
I want it Right.
Remember my car is a 2021 built on December 2020 during a Chinese Virus Lockdown election year.

2SS Capt · 05-09-2021, 06:30 PM

Quote:

Originally Posted by Buckwheat

Don’t trust Factory Line Union Workers.
I want it Right.
Remember my car is a 2021 built on December 2020 during a Chinese Virus Lockdown election year.

Did you change the oil, brake and Trans fluid too?

Buckwheat · 05-09-2021, 07:15 PM

I purchased this car in Florida. It was on their showroom floor.
I live in Louisiana. I had it shipped to New Orleans. I never drove it until I brought it to my local dealership for a complete check front to back.
Brake level is ok checked at the dealership
Transmission level is ok checked at the dealership
Engine oil changed Amsoil 5w50 with AC Delco oil filter
Rear end oil changed AC Delco.
All is good.
Local dealership has a corvette Z06 certified master technician

gtfoxy · 05-09-2021, 08:03 PM

I’d imagine the break-in stuff they put in would be for a good reason. Removing it prematurely may not be the best of ideas. Maybe it stayed in the important parts of the diff.

pauly1119 · 05-10-2021, 06:37 AM

Quote:

Originally Posted by gtfoxy

Finally got around to changing it. To those that have done the first one is this about what it looked like the first time? Drain plug had a bunch of sludge & it was as black as the ace of spades.

Mine looked pretty much the same with 1500 babied miles, out of all the fluid changes this one surprised me the most.

05-07-2021, 01:52 PM	#15
LonghornMM Drives: 2020 ZL1 Camaro Join Date: Apr 2021 Location: Deer Park, TX Posts: 23	My car has just over 1K miles on it. Just ordered 2 quarts of Royal Purple 75W-90 this morning. I'll be changing the rear end oil in a week or so. Guys, any clearance issues having enough room to get the quart container above the fill hole when refilling the rear end housing? I'm hoping that I won't have to use a pump. __________________ 2020 Camaro ZL1 A10 Hawk Performance ceramic brake pads Roto-Fab Big Gulp cold air E85 flex fuel Low temp thermostat Nitto NT555R2 drag radials Custom tuned by MTI-Houston

05-08-2021, 08:17 AM	#19
KingLT1 Drives: 2016 1SS NFG A8 Join Date: Aug 2017 Location: 46804 Posts: 6,808	If you put anything other then GM fluid in the diff plan on it making noise. Now I haven't specifically tried Royal Purple but when I changed my fluid I used Mobile 1, and the diff made noise. Then tried Valvoline, also made noise. Added friction modifier, still made noise. Put AC Delco in it and it went away. __________________ 2016 NFG 1SS A8 Options-2SS Leather/NPP Perf. mods-Whipple 2.9/Fuel System/Flex Fuel/103mm TB/Rotofab Big Gulp/Cat Deletes/Corsa NPP Per. times- 10.5 @ 137 w/ 1.8 60ft Full weight on 20's 1200DA

05-08-2021, 01:32 PM	#21
LonghornMM Drives: 2020 ZL1 Camaro Join Date: Apr 2021 Location: Deer Park, TX Posts: 23	After considering everything, reading here, articles on different types of oil and talking to a good friend of mine who is a mechanical engineer and car freak who studies up on things like this, I have decided to go with the factory GM differential oil. __________________ 2020 Camaro ZL1 A10 Hawk Performance ceramic brake pads Roto-Fab Big Gulp cold air E85 flex fuel Low temp thermostat Nitto NT555R2 drag radials Custom tuned by MTI-Houston

05-07-2021, 07:10 PM	#16
gtfoxy Account Suspended Drives: '21 Wild Cherry ZL1 Join Date: Aug 2018 Location: WI Posts: 2,082	Keep in mind the GM fluid comes with the friction additive mixed in. Not sure about the RP stuff, but I’m going with no. Get a pump. I have a cheap auto parts store one & it is soooo much easier. You can run a long hose up to the diff, cut a short chunk to go in the bottle & be behind the bumper pumping it in. Capacity is 1.6Qts, so 1Qt- 21.6oz.

05-09-2021, 08:47 AM	#22
Buckwheat Account Suspended Drives: 2021 Camaro ZL1 Join Date: Jan 2010 Location: Swamplands Of Louisiana Posts: 106	I just changed mine. I have a 2021 with 6 miles and never drove it until I changed the rear end oil.. BTW stick with the AC Delco rear end oil.

05-09-2021, 05:24 PM	#24
Buckwheat Account Suspended Drives: 2021 Camaro ZL1 Join Date: Jan 2010 Location: Swamplands Of Louisiana Posts: 106	Don’t trust Factory Line Union Workers. I want it Right. Remember my car is a 2021 built on December 2020 during a Chinese Virus Lockdown election year.

05-09-2021, 07:15 PM	#26
Buckwheat Account Suspended Drives: 2021 Camaro ZL1 Join Date: Jan 2010 Location: Swamplands Of Louisiana Posts: 106	I purchased this car in Florida. It was on their showroom floor. I live in Louisiana. I had it shipped to New Orleans. I never drove it until I brought it to my local dealership for a complete check front to back. Brake level is ok checked at the dealership Transmission level is ok checked at the dealership Engine oil changed Amsoil 5w50 with AC Delco oil filter Rear end oil changed AC Delco. All is good. Local dealership has a corvette Z06 certified master technician

05-09-2021, 08:03 PM	#27
gtfoxy Account Suspended Drives: '21 Wild Cherry ZL1 Join Date: Aug 2018 Location: WI Posts: 2,082	I’d imagine the break-in stuff they put in would be for a good reason. Removing it prematurely may not be the best of ideas. Maybe it stayed in the important parts of the diff.

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