differential refill - how much ?
Thread Starter
Instructor
Joined: Jan 2003
Posts: 188
Likes: 2
From: Flowermound Tx
differential refill - how much ?
The car is starting to grind a bit even in a straight line at low speeds now and then. I plan on draining the differential and starting over. I see kits available online that contain 1-4oz bottle of GM posi additive. I thought I'd read before of members adding two bottles or 8oz. In your opinion is 4oz enough or should I add 8 ? Also, would you recommend using GM gear lube or has anyone had better luck with mobil 1 or royal purple ?
Thanks for your help
Thanks for your help
Drifting
Joined: Aug 2005
Posts: 1,430
Likes: 8
From: Hamilton NJ
Originally Posted by Porch40
In your opinion is 4oz enough or should I add 8 ? Also, would you recommend using GM gear lube...
Racer
Joined: Dec 2004
Posts: 379
Likes: 0
From: Fairfield Texas
Several folks on the Forum have been using Royal Purple Max Gear
with good results.Royal Purple is supposed to already contain the
positraction additive so no need to add Posi additive. I bought 64oz.
(2 qts) to do My 79 and will change it as soon as I can figure out how to get the old lubricant out.Car only has 15,000 miles on it but rear
is whining on deceleration. Gonna see if this will help.
with good results.Royal Purple is supposed to already contain the
positraction additive so no need to add Posi additive. I bought 64oz.
(2 qts) to do My 79 and will change it as soon as I can figure out how to get the old lubricant out.Car only has 15,000 miles on it but rear
is whining on deceleration. Gonna see if this will help.
Team Owner
Joined: Jul 1999
Posts: 26,545
Likes: 46
From: Huntersville NC
I did that. Used 2 X 4 oz "limited slip differential additive" (If you are looking for the word "posi" you will be disappointed!) and I bought the GM lube by part number. Removing the rear passenger wheel made access a lot easier! When finished you are supposed to drive in a few figure 8's to give the differential a workout and spread the lube all over the clutches.
I was just starting to get a little chatter, especially after coming off the highway. Haven't heard a peep in 2 or 3 years after the drain and refill. (Actually it's a "suck it out" not a drain)
I was just starting to get a little chatter, especially after coming off the highway. Haven't heard a peep in 2 or 3 years after the drain and refill. (Actually it's a "suck it out" not a drain)
Burning Brakes
Joined: May 2005
Posts: 826
Likes: 0
From: Pearl MS
I had my rear end housing out when I changed the fluid. I too used 2 4oz bottles of the additive and about a qt and a little from the 2 qt bottles of gear oil that I bought from the Chevy dealer.
One of the things that you can use to get (suck) the old oil out could be a turkey baster (sp?) - just get some tubing that is a little longer and more flexible - replace the tube that comes on the baster and get out all of the old stuff that you can.
One of the things that you can use to get (suck) the old oil out could be a turkey baster (sp?) - just get some tubing that is a little longer and more flexible - replace the tube that comes on the baster and get out all of the old stuff that you can.
Team Owner
Joined: Jun 2004
Posts: 20,216
Likes: 4
From: Smile, it's just the internet.
Originally Posted by skydaddy
One of the things that you can use to get (suck) the old oil out could be a turkey baster (sp?) - just get some tubing that is a little longer and more flexible - replace the tube that comes on the baster and get out all of the old stuff that you can.
Instructor
Joined: Nov 2005
Posts: 140
Likes: 0
From: Oceanside CA
Kragen's Auto Parts has a nice suction gun that works great. At first I thought this would be a messy deal as I have used the turkey baster thing before. With the suction gun it was a pleasure to use for both draining and refilling. I bought 2 quarts of Mobil 1 75W-90 synthetic and one 4 oz. bottle of additive from the local Chevy dealership. The additive was $8.00 plus tax. The suction gun was $11.88 including tax. Removing the spare tire carrier made the job a lot easier. I had to remove the two bolts that hold the drop rods to the differential. I enlongated the holes in the carrier so now I can just drop it without removing the rods. Also took the carrier and had it chrome plated for $110.00. Looks great!!!!
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Thread Starter
Instructor
Joined: Jan 2003
Posts: 188
Likes: 2
From: Flowermound Tx
I went ahead and ordered a kit with the lube, additive, gasket, and vent(?). Now that I've got the spring out of the way I figured I'd remove the cover and reseal it all. From looking at the side it seems like I could remove the cover without removing the frame cross member just above it. Does anyone know if this member needs to be removed ?
Thanks for your help
Thanks for your help
Safety Car
Joined: May 2005
Posts: 4,176
Likes: 7
From: Jennings LA
Originally Posted by Porch40
I went ahead and ordered a kit with the lube, additive, gasket, and vent(?). Now that I've got the spring out of the way I figured I'd remove the cover and reseal it all. From looking at the side it seems like I could remove the cover without removing the frame cross member just above it. Does anyone know if this member needs to be removed ?
Thanks for your help
Thanks for your help
Safety Car
Joined: Jul 2002
Posts: 4,269
Likes: 3
From: St. Charles IL
Cruise-In 5-6-7-8-9-11-12 Veteran
A CI-6 Car Show Winner
Well, I probably did it wrong, but I used only one bottle of the GM additive and about 2 bottles of the GM lube. I haven't had any problems though, this will be the 3rd season. Same thing in my 2500 Suburban, but seems like it might have taken 3 bottles of lube. 145,000 miles and still drives like new.
Burning Brakes
Joined: May 2005
Posts: 826
Likes: 0
From: Pearl MS
CGGorman Quote:
Yet another reason to have an electric vacuum pump handy if you own an old Vette...
Yet another reason to have an electric vacuum pump handy if you own an old Vette...
Yeah - I know - I actually have a hand pump vacuum canister that I perminently borrowed from work. We got it from a lab supply house for the work I do. I did not figure that he had axcess to something like this and suggested what I use to use. I have also used the big cathedore (sp?) syringes with a piece of tubing on the end to suck the stuff out.
Safety Car
Joined: Jun 2004
Posts: 4,652
Likes: 80
From: Lakeland Florida
I used a manual hand pump that I bought from the auto store for about $8. It was well worth it.
One thing to do is to put in the additive FIRST. Because if you fill up the differential with fluid until it dribbles out, then how do you put in the additive?
kdf
One thing to do is to put in the additive FIRST. Because if you fill up the differential with fluid until it dribbles out, then how do you put in the additive?
kdf
Safety Car
Joined: Apr 2001
Posts: 3,581
Likes: 28
From: Spring, Texas
Originally Posted by chevylit
I bought 64oz.
(2 qts) to do My 79 and will change it as soon as I can figure out how to get the old lubricant out.
(2 qts) to do My 79 and will change it as soon as I can figure out how to get the old lubricant out.
Racer
Joined: Dec 2004
Posts: 379
Likes: 0
From: Fairfield Texas
Originally Posted by SharkAttack
To remove the old fluid, I use a drill pump. Don't know if they still make them, but it's basically a shaft that goes into your electric drill with an enclosed impeller. The hose ports accept a standard garden hose.
MityVac hand vacuum pump with the brake bleeder attachment.The
bottle is so small it took forever because everytime the little bottle
gets full it has to be emptied.Anyway filled it up with 75/90 Royal
Purple Max Gear,trying to get rid of a slight "whine" I can hear on
deceleration. Haven't driven it enough yet to see if I succeeded.