Changing Diff Fluid
Thread Starter
Le Mans Master
Joined: Apr 2001
Posts: 5,941
Likes: 281
From: Was New Orleans but swam to Baton Rouge LA
Cruise-In IX Veteran
Changing Diff Fluid
I went to the store today to pick up everything I should need to do this job. I got one quart of 75w90 Mobil 1 gear oil and two bottles of Limited slip diff additive. I plan on sucking the old fluid out with the pump tommorrow and filling it up. Is there anything I am missing or that might wrong??
Mark B.
Mark B.
Abby Normal
Joined: Dec 2001
Posts: 53,434
Likes: 92
From: Press "2" for English
Re: Changing Diff Fluid (Sigforty)
nothing else comes to mind. you pretty much described exactly what i did to mine about a month ago, except i put in redline. mine even saw some pretty heavy track time a couple weeks back and the last thing i was worried about was the diff. have fun! :smash:
Abby Normal
Joined: Dec 2001
Posts: 53,434
Likes: 92
From: Press "2" for English
Re: Changing Diff Fluid (jerryp58)
i don't know about synthetics in general but redline advertises that it is not necessary with their fluid. i have been running it for about three years now and have not noticed any clutch chatter or unusual whining from the gears. you could probably search mobils site and they might say if it's o.k. to run w/o the additive.
Tech Contributor
Joined: Aug 1999
Posts: 15,173
Likes: 3,982
From: Connecticut, USA
Re: Changing Diff Fluid (jerryp58)
I was told this week by a guy at Tom's, in CA, not to use synthetic oil because it wil cause problems in the differential. They recommended the GM additive and Lucas 90-145 oil. A few folks here use the synthetic and haven't had a problem. I last used Valvoline 90wt that was supposed to be good with posi's and had more knocking then ever. I'm going to drain and try either the Lucas or go back to GM oil.
Gary
Gary
Burning Brakes
Joined: Feb 1999
Posts: 1,165
Likes: 1
From: San Jose CA
Re: Changing Diff Fluid (jerryp58)
Jerryp58,
Redline 75W90 has already limited slip additive in it. They have also a 75W90NS which has NO additive in it.
I use the 75W90 in my '81 and have no problems at all.
Hope this helps
Roger
:cheers:
Redline 75W90 has already limited slip additive in it. They have also a 75W90NS which has NO additive in it.
I use the 75W90 in my '81 and have no problems at all.
Hope this helps
Roger
:cheers:
Melting Slicks
Joined: May 1999
Posts: 2,897
Likes: 0
From: Moon Township PA
Re: Changing Diff Fluid (Sigforty)
You got it all. I would drive the car for a few miles to warm the stuff up. Otherwise, it is like trying to suck out split pea soup.
As far as the other posters and what to use, I have been using Mobil 1 sytnthetic differential oil for quite a while now. If I didn't like the Mobil stuff so well, the only other one I would use is the GM brand of differential oi. I also add two containers of GM positraction additive from the Chevy dealer. There is a guy not far from me who rebuilds differentials for a living and he likes both GM and Mobil oils. He also says to use the GM brand of posi additive.
Gary
As far as the other posters and what to use, I have been using Mobil 1 sytnthetic differential oil for quite a while now. If I didn't like the Mobil stuff so well, the only other one I would use is the GM brand of differential oi. I also add two containers of GM positraction additive from the Chevy dealer. There is a guy not far from me who rebuilds differentials for a living and he likes both GM and Mobil oils. He also says to use the GM brand of posi additive.
Gary
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Melting Slicks
Joined: Aug 2000
Posts: 2,310
Likes: 1
Re: Changing Diff Fluid (rhoeven)
Roger, Thanks. I had my diff fluid changed last year, but the guy said it was kind of "murky". I figured it'd be pretty easy to do with my spare out of the way, so I'm going to change it myself and see what it looks like after a year. I haven't decided about synthetic or not.
Mark B., good luck & please post how you make out.
Mark B., good luck & please post how you make out.
Thread Starter
Le Mans Master
Joined: Apr 2001
Posts: 5,941
Likes: 281
From: Was New Orleans but swam to Baton Rouge LA
Cruise-In IX Veteran
Re: Changing Diff Fluid (jerryp58)
I just woke up about 30 minutes ago and am getting ready to change the fluid. Thands for the info and reassurance I am heading the right direction. I will let you know how it went after I finish.
Mark B.
Mark B.
