Differential Positraction Lube

[Mark Nevins]

Re: Differential Positraction Lube

I would like to change the fluid in my 72 LT-1 to Redline. In doing so, Should I still add the GM 4 Oz. additive, or is the synthetic sufficient on its own?

[Mark Nevins]

Re: Differential Positraction Lube

I would like to change the fluid in my 72 LT-1 to Redline. In doing so, Should I still add the GM 4 Oz. additive, or is the synthetic sufficient on its own?

[Gary Schisler]

Re: Differential Positraction Lube

I can't speak about Redline, but when I changed out my 66's differential fluid this spring, I put in Mobil 1 synthetic and two containers of GM brand differential lube. There have been many posts in the recent past and even earlier about the subject of GM posi additive. There have been questions about noisy rear ends, sticking posi units, and noise in general. Most of these symptoms have reportedly gone away with the addition of the GM brand posi additive. I always add this and recommend others to do the same. This is a cheap insurance policy. BTW, in the past I used aftermarket posi additive but recently I found that the difference in price was not worth worrying about. The GM brand was less that a dollar more for the two containers.

[Gary Schisler]

Re: Differential Positraction Lube

I can't speak about Redline, but when I changed out my 66's differential fluid this spring, I put in Mobil 1 synthetic and two containers of GM brand differential lube. There have been many posts in the recent past and even earlier about the subject of GM posi additive. There have been questions about noisy rear ends, sticking posi units, and noise in general. Most of these symptoms have reportedly gone away with the addition of the GM brand posi additive. I always add this and recommend others to do the same. This is a cheap insurance policy. BTW, in the past I used aftermarket posi additive but recently I found that the difference in price was not worth worrying about. The GM brand was less that a dollar more for the two containers.