Rear diff fluid change - Page 2 - ZR-1 Net Registry Forums

Aurora40 · 01-19-2006

Well, I got it done tonight. I jacked up the passenger rear, pulled the tire, and sucked out the old stuff. Then I pulled the jackstand out and lowered the car on the jack until it was level and filled it up. I used about an 18" length of hose to fill the diff. Then I capped it up, jacked it back up, and put the tire on.

I have a question, though. I used about 1.5 liters of Mobil 1, plus the 4 ounces of rear diff lube. How much fluid does the diff hold total? Was I pretty close at getting it all out?

As an aside, man does gear oil stink!

ZR1 MK · 01-19-2006

Two tips.
1. Mobil 1 doesnt require the posi additive.
2. Install a magnetic fill plug while your there. Standard GM size.

Aurora40 · 01-19-2006

Well it's already back together. But for a magnetic one, you mean standard rear diff size? Or what? GM sells this?

Does it matter if I put the additive in anyway? I don't even know what is in the additive that makes it different.

Any idea on the total fluid capacity of the diff?

ZR1 MK · 01-19-2006

Additive is for the clutch. It wont damage anything if used in the Mobil 1. The plug should be a standard size (diameter and thread pitch). Look for one at a local auto parts store.

Tom · 01-19-2006

I believe the differential fill plug has tapered pipe threads, a standard oil pan drain plug will not fit since they use straight threads. You fill the differential to the bottom of the fill hole so a magnetic fill plug would provide very little benefit since it is above the fluid level.

ZR1 MK · 01-19-2006

Quote:

Originally Posted by Tom

I believe the differential fill plug has tapered pipe threads, a standard oil pan drain plug will not fit since they use straight threads. You fill the differential to the bottom of the fill hole so a magnetic fill plug would provide very little benefit since it is above the fluid level.

Who mentioned an oil pan drain plug? I wouldnt have mentioned a magnetic fill plug if it didnt work. The fluid gets thrown around when under way. The plug collects plenty of debris, so your wrong.

Tom · 01-19-2006

When you mentioned standard size (diameter and pitch) I thought you were referring to a standard straight thread magnetic oil pan drain plug since I have not noticed any magnetic pipe thread plugs at my local part stores. What part stores have you seen them at?

ZR1 MK · 01-19-2006

I got the plug many years ago from a local auto parts store. It was originally in my 1970 Z28 Camaro and was transfered to my 1990 ZR1 Corvette. Ask for a diff plug, but one thats magnetic.
Since the engine and trans didnt have magnetic plugs thats where readily available at the time, I use glued on magnets. And these also collect debris. The trans accumulates plenty of non-magnetic particles, so a proper drain interval is important.

ZR1 MK · 01-21-2010

I did the drain plug shortly after my last, many moons ago, post.

Fluid changes are much easier and all the fluid gets drained. Helps get the particles out too, for those not using a magnetic fill/drain plug.

01-19-2006	#11
Aurora40 Join Date: May 2005 Location: Leesburg, VA Posts: 2,713	Re: Rear diff fluid change Well, I got it done tonight. I jacked up the passenger rear, pulled the tire, and sucked out the old stuff. Then I pulled the jackstand out and lowered the car on the jack until it was level and filled it up. I used about an 18" length of hose to fill the diff. Then I capped it up, jacked it back up, and put the tire on. I have a question, though. I used about 1.5 liters of Mobil 1, plus the 4 ounces of rear diff lube. How much fluid does the diff hold total? Was I pretty close at getting it all out? As an aside, man does gear oil stink! __________________ Bob Saveland Former owner of #2517 [IMG]http://a.random-image.net/aurora40/vette.jpg[/img]

01-19-2006	#12
ZR1 MK Join Date: Aug 2005 Location: NY Posts: 143	Re: Rear diff fluid change Two tips. 1. Mobil 1 doesnt require the posi additive. 2. Install a magnetic fill plug while your there. Standard GM size. __________________ Mike 427 cu in LT5 [URL="http://zr1mk.weebly.com"]http://zr1mk.weebly.com[/URL]

01-19-2006	#13
Aurora40 Join Date: May 2005 Location: Leesburg, VA Posts: 2,713	Re: Rear diff fluid change Well it's already back together. But for a magnetic one, you mean standard rear diff size? Or what? GM sells this? Does it matter if I put the additive in anyway? I don't even know what is in the additive that makes it different. Any idea on the total fluid capacity of the diff? __________________ Bob Saveland Former owner of #2517 [IMG]http://a.random-image.net/aurora40/vette.jpg[/img]

01-19-2006	#14
ZR1 MK Join Date: Aug 2005 Location: NY Posts: 143	Re: Rear diff fluid change Additive is for the clutch. It wont damage anything if used in the Mobil 1. The plug should be a standard size (diameter and thread pitch). Look for one at a local auto parts store. __________________ Mike 427 cu in LT5 [URL="http://zr1mk.weebly.com"]http://zr1mk.weebly.com[/URL]

01-19-2006	#15
Tom Join Date: Jan 2004 Location: Southern CA Posts: 108	Re: Rear diff fluid change I believe the differential fill plug has tapered pipe threads, a standard oil pan drain plug will not fit since they use straight threads. You fill the differential to the bottom of the fill hole so a magnetic fill plug would provide very little benefit since it is above the fluid level.

01-19-2006	#17
Tom Join Date: Jan 2004 Location: Southern CA Posts: 108	Re: Rear diff fluid change When you mentioned standard size (diameter and pitch) I thought you were referring to a standard straight thread magnetic oil pan drain plug since I have not noticed any magnetic pipe thread plugs at my local part stores. What part stores have you seen them at?

01-19-2006	#18
ZR1 MK Join Date: Aug 2005 Location: NY Posts: 143	Re: Rear diff fluid change I got the plug many years ago from a local auto parts store. It was originally in my 1970 Z28 Camaro and was transfered to my 1990 ZR1 Corvette. Ask for a diff plug, but one thats magnetic. Since the engine and trans didnt have magnetic plugs thats where readily available at the time, I use glued on magnets. And these also collect debris. The trans accumulates plenty of non-magnetic particles, so a proper drain interval is important. __________________ Mike 427 cu in LT5 [URL="http://zr1mk.weebly.com"]http://zr1mk.weebly.com[/URL]

01-21-2010	#19
ZR1 MK Join Date: Aug 2005 Location: NY Posts: 143	Re: Rear diff fluid change I did the drain plug shortly after my last, many moons ago, post. Fluid changes are much easier and all the fluid gets drained. Helps get the particles out too, for those not using a magnetic fill/drain plug. __________________ Mike 427 cu in LT5 [URL="http://zr1mk.weebly.com"]http://zr1mk.weebly.com[/URL]