Rear gear lube
Thread Starter
Instructor
Joined: Feb 2003
Posts: 176
Likes: 0
From: jacksonville florida
Rear gear lube
What kind of lube should I put in the differential of 73 automatic coupe and how do I do it? I have a very slight pinion seal leak and would like to top it off. Thanks :confused:
[Modified by hauk, 10:00 PM 7/1/2003]
[Modified by hauk, 10:01 PM 7/1/2003]
[Modified by hauk, 9:33 AM 7/2/2003]
[Modified by hauk, 10:00 PM 7/1/2003]
[Modified by hauk, 10:01 PM 7/1/2003]
[Modified by hauk, 9:33 AM 7/2/2003]
Team Owner
Joined: Jul 1999
Posts: 26,545
Likes: 46
From: Huntersville NC
Re: Rear gear lube (hauk)
What kind of lube should I put in the differential of 73 automatic coupe and how do I do it? Thanks :confused:
Step 1 is remove the old crap, ideally with some type of suction apparatus, either a suction pump or a turkey baster. Access is much easier if you remove the passenger side rear wheel. Then put in the additive. Then put in the differential oil until it dribbles out the top. I put a length of clear plastic hose on the top of my oil bottle and squeeze it out, and into the oil fill hole. :) MJ
[Modified by MNJack, 10:42 PM 7/1/2003]
Burning Brakes
Joined: May 2003
Posts: 910
Likes: 20
From: Shorewood IL
Re: Rear gear lube (MNJack)
I've got an '80 that I just bought and I want to change the fluid in mine as well. From what I have read the 1980's had posi traction. When I looked at my rear end there's a red tag on there stating that I should refill it with limited slip. Is there a difference between the posi traction additive and "limited slip" additive?
Thanks for the help.
:auto:
Thanks for the help.
:auto:
Safety Car
Joined: Dec 1999
Posts: 3,605
Likes: 839
From: PA
Re: Rear gear lube
Is there a difference between the posi traction additive and "limited slip" additive?
Positraction is the name GM used to market its limited slip differential, so yes, they are the same. Other manufacturers used different marketing names for their limited slip diferentials.
Use a good 80-90W gear oil with a GL-5 rating in your differential and you'll be just fine.
For all the hype it gets, the GM positraction additive isn't all that great... Try the Ford limited slip additive, I'm pretty sure the part number is C8AZ-19B546A... Much better than what GM sells.
Regards,
Melting Slicks
Joined: Aug 2001
Posts: 3,050
Likes: 124
From: Wichita KS
Re: Rear gear lube (hauk)
I use the GM differential lubricant as specified in your owner's manual and shop manual. The Limited-Slip Differential Lubricant Additive GM 1052358 is important to add (first).
Incidentally, the additive part number for my 2003 EB convertible is the same as my 1980 - must be needed and it must work ok.
Incidentally, the additive part number for my 2003 EB convertible is the same as my 1980 - must be needed and it must work ok.
Team Owner
Joined: Jul 1999
Posts: 26,545
Likes: 46
From: Huntersville NC
Re: Rear gear lube (Rowdy Rat)
Try the Ford limited slip additive, I'm pretty sure the part number is C8AZ-19B546A... Much better than what GM sells.
Regards,
Regards,
Actually, one confusing thing as you try to learn this stuff - All you read about is "POSI-additive, posi, posi, posi, dont forget the GM POSI-additive" and then you buy the stuff from the GM dealer and the letters "POSI" do not appear on the tube! It is called "limited slip differential" additive. So until you figure out they are the same thing it is a bit confusing! :) MJ
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Melting Slicks
Joined: Sep 2002
Posts: 2,783
Likes: 2
From: Engineers do it better.
Re: Rear gear lube (MNJack)
Many have their favorite brand of synthetic, but it's hard to beat the GM differential lube, available from your GM dealer. Don't forget to add the GM positraction additive, also known as limited slip differential additive, 1 or 2 tubes depending on which size tube you get.
Step 1 is remove the old crap, ideally with some type of suction apparatus, either a suction pump or a turkey baster. Access is much easier if you remove the passenger side rear wheel. Then put in the additive. Then put in the differential oil until it dribbles out the top. I put a length of clear plastic hose on the top of my oil bottle and squeeze it out, and into the oil fill hole. :) MJ
Step 1 is remove the old crap, ideally with some type of suction apparatus, either a suction pump or a turkey baster. Access is much easier if you remove the passenger side rear wheel. Then put in the additive. Then put in the differential oil until it dribbles out the top. I put a length of clear plastic hose on the top of my oil bottle and squeeze it out, and into the oil fill hole. :) MJ
Safety Car
Joined: Dec 1999
Posts: 3,605
Likes: 839
From: PA
Re: Rear gear lube
Heresey!!!!!! :lol:
Anyone who knows me is aware that I purchase GM parts for my restorations whenever I can... But if someone says they have a "better mousetrap", I'm willing to give it a try if the claims look reasonable. Currently, the Ford limited slip additive is a better product than what GM offers. I can think of a few shops out there that agree with me on this so I haven't gone over the edge just yet.
I guess that this is a bad time to bring up Ford DOT 3 brake fluid? :)
Regards,
Le Mans Master
Joined: Aug 2000
Posts: 6,362
Likes: 7
From: Brazos TX
Cruise-In IV Veteran
Cruise-In V Veteran
Re: Rear gear lube (hauk)
I guess I'll be the first to state that I use Mobil One synthetic. The stuff is great for all kinds of reasons and you don't need any additives. I had a clutch chatter problem when I first got the car. I changed to Mobil One and (after a few tight turns in a parking lot) it went away. 50,000 happy miles later and it's still going strong. Don't forget to do the 5 to 7 tight turns in each direction after you get the new oil in. It helps lube the clutches with the new oil.
Melting Slicks
Joined: Feb 2003
Posts: 3,053
Likes: 4
St. Jude Donor '03,'11
Re: Rear gear lube (burners)
i don't like running the limited slip additive. I kinda like the way the rear end jerks and clunks when going around tight corners. lets you know your posi is grabbing good.
Melting Slicks
Joined: Aug 2001
Posts: 3,050
Likes: 124
From: Wichita KS
Re: Rear gear lube (turtlevette)
i don't like running the limited slip additive. I kinda like the way the rear end jerks and clunks when going around tight corners. lets you know your posi is grabbing good.
Le Mans Master
Joined: Aug 2001
Posts: 8,164
Likes: 0
From: ohio
Re: Rear gear lube (hauk)
yeah i use mobil-1 synthetic too, even though it is pretty damn pricey and hard to find. I've always noticed that the rear end felt alot smoother in anything i put mobil-1 synthetic into the rear.
As for how to do it, you might as well just buy a rear end cover gasket along with the oil. Then you just put a pan under the rear end and take the cover off.
Scrap all the old gasket off, put the new one on. I like to use brake cleaner to clean the gears up in the rear, to get rid of any gunk or metal shavings in there. Then reinstall the cover. This way, you'll have the satisfaction of knowing you have a good gasket back there.
Getting fluid in the rear end is the hard part. The easiest thing is to just buy one of those cheap fluid pumps you see at the parts store and pump it from the container into the rear end.
As for how to do it, you might as well just buy a rear end cover gasket along with the oil. Then you just put a pan under the rear end and take the cover off.
Scrap all the old gasket off, put the new one on. I like to use brake cleaner to clean the gears up in the rear, to get rid of any gunk or metal shavings in there. Then reinstall the cover. This way, you'll have the satisfaction of knowing you have a good gasket back there.
Getting fluid in the rear end is the hard part. The easiest thing is to just buy one of those cheap fluid pumps you see at the parts store and pump it from the container into the rear end.
Burning Brakes
Joined: Mar 2001
Posts: 1,211
Likes: 5
From: Nashville TN
Re: Rear gear lube (RJR99SS)
I just did a switch to Redline 75W90 synthetic. I run it in the BMW and its reallly great stuff. It comes with the Limited Slip additive already mixed in. Great Stuff.
Melting Slicks
Joined: Dec 2000
Posts: 3,407
Likes: 2
From: Carmichael CA
Re: Rear gear lube (hauk)
I use Pennzoil or Valvoline 80-W90 GL-5 Gear Oil and the limited slip additive. What I do is pour out a little bit of oil out of each quart and squirt half the additive in each bottle. I then shake the bottles up real good to mix the additive up. This will save some possible wear on the gears, and will avoid any need for a break-in period.
Drifting
Joined: Jul 2001
Posts: 1,418
Likes: 1
Re: Rear gear lube (Rowdy Rat)
[b]
Currently, the Ford limited slip additive is a better product than what GM offers. I can think of a few shops out there that agree with me on this so I haven't gone over the edge just yet.
Regards,
Currently, the Ford limited slip additive is a better product than what GM offers. I can think of a few shops out there that agree with me on this so I haven't gone over the edge just yet.
Regards,
Melting Slicks
Joined: Nov 2001
Posts: 2,668
Likes: 43
From: Eastern US XX
Re: Rear gear lube (RJR99SS)
As for how to do it, you might as well just buy a rear end cover gasket along with the oil. Then you just put a pan under the rear end and take the cover off.
Melting Slicks
Joined: Feb 2003
Posts: 2,330
Likes: 6
From: Long Island NY
Re: Rear gear lube (Rockn-Roll)
I just changed my rear fluid, I spilled about 1 oz of the 4 oz additive. Would adding another 4 oz's hurt, help, or make no diiference? Or just add half the bootle?
