1950-1966 [Subscribe to Daily Digest] |
"I appreciate this thread. I have been in communication with Redline. First they told me I should use the 75W-90, which is a GL-5. I asked about issues with damage to yellow metal. They first said that it wouldn't be a problem with their addiditives and gave me a bunch of technical stuff about viscosity and said that the viscosity shouldn't be a problem at the higher end. They then emailed me back and said that after discussing with their chemist, the Redline MTL would work. However, it is not an EP lube. They said that the type of transmission in my 96 really does not need an EP. Now I am really confused as the shop manual and owners manual says is should be and EP. I had been using the Amsoil 75W-90 EP, which is a GL-5. I am somewhat concerned about the yellow metal issue and that is why I was looking for something else. Is the Quaker State referred to earlier an EP lube? Maybe for a once a season tranny oil change, it would be worth ordering from europe."
This whole business is indeed a little confusioning. I am not an expert but have done some research and do try to keep up. Here is what I think, & am happy to accept correction if anyone knows better.
First, there are two features of transmission lubricant that we care about: Viscosity (eg 80W90) and Additive Package (eg GL4, GL5).
1) Viscosity: Autobooks manual (Autobook 764) specifies EP-SAE 80. Haynes manual (book number illegible on my copy) specifies Castrol Hypoy Light. I presume these are equivalent specifications. "EP" stands for Extreme Pressure. "Hypoy" implies for use with hypoid gears, which are differential (ring and pinion) gears with a lot of sliding contact on the teeth, requiring EP additives to prevent metal-to-metal contact and consequent scoring and destruction. Saab recommends 80 viscosity EPlubricant. Conventional wisdom is that many transmissions have been ruined by use of heavier lubricants (higher numbers, like 90, are heavier) because the oiling process to certain parts of the transmission is inadequate.
I would not use any lubricant with a number higher than 80 in its viscosity designation in a Saab model 97 or lower.
I believe a 75 or 75W (let's not go there right now) or various others such as Redline MTL which claims to meet viscosity requirements of 70W, 75W, and 80 (no W) and also SAE30, 10W30, and 5W30 (these are motor oil designations; many Hondas and others specify motor oil such as 10W30 in manual transmissions) should be fine.
I am not a shill for Redline but have had good technical support from them and trust their products and know that many serious racers support them.
Repeat, DO NOT PUT ANY OIL WITH A NUMBER HIGHER THAN 80 INTO YOUR VINTAGE SAAB.
2) Additives. GL4 is an additive package to the basic lubricant that works well in conventional manual transmission designs. It is less slippery than GL5. The problem with the more slippery GL5 is that gear changes may cause crashing of the gears because the slipperiness of the lubricant (to prevent wear of differential gears) also works on the synchro rings, and the synchro rings want a certain amount of friction (= less slipperiness) to operate as designed.
So, the GL5 package may cause unsatisfactory shifting in a transmission designed for GL4. This will of course depend on driver habits and needs.
Is this complicated enough yet? More to come, but I have some business to attend to.
As far as I can determine, "EP" is equivalent to "GL5." If you want to get into the subject, there are numerous rating processes and agencies and standards that are beyond my patience to sort out.
posted by 208.53.81...
No Site Registration is Required to Post - Site Membership is optional (Member Features List), but helps to keep the site online
for all Saabers. If the site helps you, please consider helping the site by becoming a member.
 |
 |
 |
 |
 |
