Red Line oil for G50 gearbox?

[Dwight]

I have done a "little" searching on what oil would be best for my '88 G50 trannie. Fully-synthetic Red Line and Mobile 1 were recommended.
Which one? They have a lot of different oils and I don't want to put the wrong one in my trannie.
Street car, no racing.
Thanks
Dwight
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From one of the ads for Red Line products;
Red Line 75W90 Gear Oil


-Most popular Red Line gear oil, with thousands of applications for passenger cars, light trucks, and racing vehicles
-Contains additional friction modifiers for suitability with clutch-type limited slip differentials - for most LSDs, no additional friction modifiers are required
-This product is not designed for use in most manual transmissions or tranaxles, since the extreme slipperiness may cause synchronizer mesh issues that lead to shifting problems
-Recommended for API GL-5, GL-6, MT-1, MIL-L-2105E, and SAE J2360

About Redline Gear Oil for Differentials:

-Fully-synthetic formulas created from polyol ester base stocks, offer excellent lubrication under extreme conditions
-High viscosity-index (VI) to provide relatively constant viscosity and film thickness with varying temperature change
-Ester base stocks and friction modifiers provide additional slipperiness to lower operating temperatures by reducing the sliding friction in hypoid gears
-Superior shear stability and reduced oxidation compared to other synthetics and conventional gear oils
-Exceed API GL-5 specifications
-Engineered to provide the highest degree of protection and improvement of differential efficiency for better mileage, longer drain intervals, and less wear

 

[Cliff Beer]

Dwight, I can only comment from personal experience.....

I have used the Redline gear oils in a few different transaxles and can report that they work very well. Specifically, better/easier shifting (particularly from cold) than other gear oils I've used and less metal "sludge" on the magnetic pick up in the sump.

Be sure to mix the Redline 75W90 with the right combination for your transaxle (lim slip or not). In other words, you can mix the 75W90 with the 75W90 NS for the appropriate friction profile depending on whether you have the limited slip G50, or not.

Good luck!

 

[Scott]

Redline has very poor shear strength so i wouldn't use it unless you change the fluid frequently.

 

[Dwight]

Thanks everyone. I am going to use Mobil 1 75W90 LS Fully-synthetic.

Dwight

 

[Cliff Beer]

Hi Scott, perhaps you would be kind enough to share upon what basis your statement is posed? Obviously, objective technical data is the most compelling (unlike my personal experience which is obviously not of that caliber).

Thanks.

 

[EGLITOM]

Hi Dwight

check out this thread as well. A lengthy oil discussion inlcuded

http://www.gt40s.com/forum/gt40-tech-powertrain-transaxles/16212-porsche-g50-info-3.html
TOM

 

[Scott]

Hi Scott, perhaps you would be kind enough to share upon what basis your statement is posed? Obviously, objective technical data is the most compelling (unlike my personal experience which is obviously not of that caliber).

Thanks.

Amsoil did a test and published it some time ago against their oil and many other popular gear oils and redline performed poorly with regards to viscosity change when oxidized and when sheared. What impressed me about the test is it's rather unbiased. What is interesting is Royal purple also scored poorly on some tests.

I've also seen first hand what redline can do to Audi gearboxes if not changed frequently.

http://www.amsoil.com/lit/g2457.pdf

 

[Cliff Beer]

Thanks Scott, good information. Obviously, technical in nature although still potentially biased as it was prep'd by Amsoil. Example, not surprisingly Amsoil did exceptionally well......

Noted on page 6 of the report in the shear test, the Redline was actually second best behind Amsoil (as compared to 12 or so other reputable gear oils) and only very slightly behind, and ahead of all others. Looks to me like Redline did pretty well in the shear department.

Thanks again.

 

[Scott]

Thanks Scott, good information. Obviously, technical in nature although still potentially biased as it was prep'd by Amsoil. Example, not surprisingly Amsoil did exceptionally well......

Noted on page 6 of the report in the shear test, the Redline was actually second best behind Amsoil (as compared to 12 or so other reputable gear oils) and only very slightly behind, and ahead of all others. Looks to me like Redline did pretty well in the shear department.

Thanks again.

Redline performed badly in a few of the other viscosity tests, hence my comment. I've also seen Redline shear to the viscosity of water in some of these 01E's I've serviced. There's enough empirical evidence for me to not recommend it.

The question you need to ask yourself is if you want to ruin a $2000+ gearbox to save 2 dollars a liter over using the proper fluid?

Redline in my opinion would be good but you would need to change it frequently.

 

[Scott]

Thanks Scott, good information. Obviously, technical in nature although still potentially biased as it was prep'd by Amsoil. Example, not surprisingly Amsoil did exceptionally well......

Noted on page 6 of the report in the shear test, the Redline was actually second best behind Amsoil (as compared to 12 or so other reputable gear oils) and only very slightly behind, and ahead of all others. Looks to me like Redline did pretty well in the shear department.

Thanks again.

Redline performed badly in a few of the other viscosity tests, hence my comment. I've also seen Redline shear to the viscosity of water in some of these 01E's I've serviced. There's enough empirical evidence for me to not recommend it.

The question you need to ask yourself is if you want to ruin a very expensive gearbox to save a few dollars a liter over using the proper fluid?

Redline in my opinion would be good but you would need to change it frequently.

 

[andys]

Scott,

I am currently using Redline MT90. As you wouldn't recommend using the Redline oil, which oil do you believe is the most suitable for the 01e?

Andy

 

[Lindsey]

I have had numerous experiences in replacing worn out gearsets/gearboxes due to Redline oil... It would be the oil I would recommend least to anyone.

Although it looks real sparkly/pretty when drained from a trans, would make a lovely color on a car.

 

[Scott]

Scott,

I am currently using Redline MT90. As you wouldn't recommend using the Redline oil, which oil do you believe is the most suitable for the 01e?

Andy

I recommend the factory fluid (G052171A1) or an OE equivalent.

I offer Fuchs Sinto fluid which is an OE equivalent.

Motul gear 300 works good as well.