RE Fluid / Axle Lube?
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Joined: Sep 2004
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From: Germantown TN
RE Fluid / Axle Lube?
Got so many opinions from local yokels this week on what's wrong with the rear-end that I now wonder if anything is at all. So I have decided to do the simple and cheap first and proceed from there - remove the fluid myself and replace today. Yesterday, went to the closest GM dealer's parts department to get the goods. Got 2 bottles of the GM Ltd Slip Axle Lubricant Additive. I was told here & elsewhere to drain the old, add 2 bottles of this additive, and top off with 90w 'oil'(?). Sorry to sound dumb but I'm a newbie - what exactly is the '90w oil' folks are talking about? Is it another GM-only product or can I get a local Autozone? I asked that guy at the dealer parts counter and he just gave me a blank look and finally responded "well, that is what it (the lube additive) is.....don't know what else you need". Sad & Pitiful....GM parts dept have computers right on the counter but don't have the answers. Not a new discovery though - I used to own a 67 Impala SS and learned long ago that Mr. Goodwrench ain't the guy to go to most of the time....especially the older the car. I would not have gone there this time but am told that the C3 rearend has to have this lubricant and nothing else will do. Thanks for the guidance and patience with a newbie!
Le Mans Master
Joined: Sep 2000
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From: Orlando Floriduh
There are a few pruducts out there that will work but you absolutely need the additve from G/M. So it is best to just get the GM posi lube and the additive. Without that you will get posi clutch chatter and hop. I actually feels like the differential is completely destroyed... The new lube and additive works wonders.
Race Director
Joined: Feb 1999
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From: Lenoir City Tennessee
Ci 6, 8 & 10 Veteran
St. Jude Donor '05-'06-'07-'08-'09-'10-'11-'12-'13-'14-'15
If your clutches are making noise when you turn, changing the rear fluid will make a difference. Go to Autozone or whatever you have and buy gear oil. I bought 2 quarts of the normal stuff and 2 quarts of Mobil 1. I went home and took the old oil out of the diff refilled with normal oil and drove it around the block making several left and right turns. Came pulled the cheap lube out and added the Mobil 1. Never had any problems since. Hope this helps.
Tech Contributor
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From: Connecticut, USA
Use the 2 bottles of the additive and get a couple of quarts of any name brand 90 wt gear oil. It will be in any auto parts store,GM sells it too but you can use the others. I don't use the synthetic stuff,just regular old gear oil and the additive. Get the differential oil warm then you have to use a hand pump or gear pump to remove it from the fill hole on the side of the cover.
Gary
Gary
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Joined: Aug 1999
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From: Connecticut, USA
Use the 2 bottles of the additive and get a couple of quarts of any name brand 90 wt gear oil. It will be in any auto parts store,GM sells it too but you can use the others. I don't use the synthetic stuff,just regular old gear oil and the additive. Get the differential oil warm then you have to use a hand pump or gear pump to remove it from the fill hole on the side of the cover.With the RE empty or as close to it as possible,add the GM stuff,then fill to the lower part of the fill hole with the 90 wt.
Gary
Gary
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From: Germantown TN
THANX!! & Another Q
Thanks everyone for the guidance. A little voice tells me that this will do the trick. The former owner said it was recently changed but I have my doubts even though he said it sometimes takes a second change to get it quiet again.
Q: How often does this need to be done? Maybe it depends on the driving/mileage - OR - just when it starts getting a little noisy(?). My 76 is not going to see the streets very often. Thanks again.
Q: How often does this need to be done? Maybe it depends on the driving/mileage - OR - just when it starts getting a little noisy(?). My 76 is not going to see the streets very often. Thanks again.
Melting Slicks
Joined: Jan 2004
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From: New Cumberland PA
It almost sounds that you were not talking to Mr. Goodwrench. He should have known what 90w oil was. Perhaps the real Mr. Goodwrench was on vaction and the position was temporaily being filled by Mr. ********, Bubba's brother-in-law.
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From: Germantown TN
Correct
You know, I think you are right.....I don't remember seeing a wrench on his shirt. There was a different kind of symbol on his pocket. Maybe it was a set of numbies. I should have been more alert....will be more careful next time.
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Race Director
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From: Fair Oaks, OK
You can get the GM 80w 90 axle lubricant, but as others have said you can get the same thing in a different brand at AutoZone and it will work fine. The hand pump can be purchased for $8.00 from your local farm supply store (if you have Atwood's stores, i know they have them).
After you get the old out, you can use the same pump to put the new in. I put half the first quart of gear lube in, then poured the additive bottles into the half full bottle of gear lube. I put the remainder of that bottle in the diff, then filled the diff with the other bottle until it started to drip out of the fill hole. I used all but a very small amount of the 2nd quart of gear lube.
After you get finished putting the lube in, plug in, and spare tire carrier back on, take your car to an empty parking lot and do a series of "figure 8's" to work the fluid & additive into the posi unit.
I did the above and finally have a noise free differential again.
After you get the old out, you can use the same pump to put the new in. I put half the first quart of gear lube in, then poured the additive bottles into the half full bottle of gear lube. I put the remainder of that bottle in the diff, then filled the diff with the other bottle until it started to drip out of the fill hole. I used all but a very small amount of the 2nd quart of gear lube.
After you get finished putting the lube in, plug in, and spare tire carrier back on, take your car to an empty parking lot and do a series of "figure 8's" to work the fluid & additive into the posi unit.
I did the above and finally have a noise free differential again.