Transaxle oils
11-07-2010, 03:15 PM
#31
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I'm not sure exactly what you're doing. Are you removing the transaxle from your '91 to replace it with an LSD-equipped transaxle or just changing the gear oil? If the latter then use all standard gear oil. The PSD-equipped transaxle isn't a normal LSD. It is an open differential design and does not need the friction modifier.
11-07-2010, 03:38 PM
#33
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Adding the friction modifier won't hurt, I guess. But, AFAIK, it won't doing anything useful. On the other hand, I don't have any direct experience with the Red Line gear oil in PSD-equipped transaxles. The factory fill for the PSD was plain'ole GL5 75w90 non-synthetic gear oil with a 30k-mile replacement schedule. Mobil 1 synthetic has always worked for me on the street or on the track.
11-07-2010, 03:57 PM
#34
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Hey Dave, I'm a little confused. From the Red Line website, the 75W90NS "contains extreme pressure additives like our 75W90 GL-5 oil, but lacks friction modifiers to balance slipperiness." whereas the 75W90 standard stuff , "contains additional friction modifiers for suitablity with clutch-type limited slip differentials - for most LSDs, no additional friction modifiers are required."
So, the NS stuff has no friction modifiers but the standard stuff does. Based on that would you recommend the 75W90NS? From reading other posts I guess the complaint on the NS stuff is that the LSDs can get a little chattery so a mix of the NS and non-NS stuff is recommended by some people. Not sure if the PSD would have the same problem with chatter since it's different than the LSD.
So, the NS stuff has no friction modifiers but the standard stuff does. Based on that would you recommend the 75W90NS? From reading other posts I guess the complaint on the NS stuff is that the LSDs can get a little chattery so a mix of the NS and non-NS stuff is recommended by some people. Not sure if the PSD would have the same problem with chatter since it's different than the LSD.
11-07-2010, 07:14 PM
#35
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Dan, I'm far from an expert on this and having looked at Red Line's site, I think I'm less of an expert after 
However, one thing that bothers me is:
From http://www.redlineoil.com/product.aspx?pid=47&pcid=7
"MTL, MT-85 & MT-90 are not for use in differentials with hypoid gears"
Unless I'm mistaken that means not for use in our transaxles (with hypoid gears ... and, someone will correct me if I'm wrong.)
After reading the RL site, I'm not sure why you'd want NS in there anyway unless you've got cranky synchros?
However, one thing that bothers me is:
From http://www.redlineoil.com/product.aspx?pid=47&pcid=7
"MTL, MT-85 & MT-90 are not for use in differentials with hypoid gears"
Unless I'm mistaken that means not for use in our transaxles (with hypoid gears ... and, someone will correct me if I'm wrong.)
After reading the RL site, I'm not sure why you'd want NS in there anyway unless you've got cranky synchros?
11-07-2010, 08:20 PM
#36
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Not sure what kind of information you are looking for....and I'm not about to say anything negative.
However, I won't warranty one of my rebuilt gearboxes when Redline is used....
Do yourself a favor and go over to Autozone and buy some 75/90 Mobil 1 LS....you can never do anything with your 928 that this gearoil won't take care of.
However, I won't warranty one of my rebuilt gearboxes when Redline is used....
Do yourself a favor and go over to Autozone and buy some 75/90 Mobil 1 LS....you can never do anything with your 928 that this gearoil won't take care of.
11-07-2010, 09:19 PM
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11-07-2010, 11:35 PM
#39
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Not sure what kind of information you are looking for....and I'm not about to say anything negative.
However, I won't warranty one of my rebuilt gearboxes when Redline is used....
Do yourself a favor and go over to Autozone and buy some 75/90 Mobil 1 LS....you can never do anything with your 928 that this gearoil won't take care of.
However, I won't warranty one of my rebuilt gearboxes when Redline is used....
Do yourself a favor and go over to Autozone and buy some 75/90 Mobil 1 LS....you can never do anything with your 928 that this gearoil won't take care of.
I'd appreciate your info.
Last edited by BC; 11-08-2010 at 04:29 PM.
11-08-2010, 09:43 AM
#40
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11-08-2010, 11:38 AM
#42
I have run redline heavyweight in my GT for years now...and run the lightweight in my PSD track car box..
as far as LSD and PSD are concerned...are they not basically the same thing...except the PSD has more clutches and is controlled by a pump/slave/release arm setup...rather than just being set at a set percentage....I'll be locking my PSD in the track car to some slip percentage since I can't run the PSD pump setup anyway....so it's just a big heavy 8 disc lsd in that case...so the friction modifier should work as it would in the GT's standard 40% LSD...
and yes..Greg...please expand on your dislike of Redline gear oil..
as far as LSD and PSD are concerned...are they not basically the same thing...except the PSD has more clutches and is controlled by a pump/slave/release arm setup...rather than just being set at a set percentage....I'll be locking my PSD in the track car to some slip percentage since I can't run the PSD pump setup anyway....so it's just a big heavy 8 disc lsd in that case...so the friction modifier should work as it would in the GT's standard 40% LSD...
and yes..Greg...please expand on your dislike of Redline gear oil..
