Here's my $.02: Put some Dexron ATF in there and nothing else, they print it on the cap for a reason. Secondly, the notchy feeling is probably the power steering belt.
the numbers don't really mean anything it's just the next succession, all it's really saying is that dexIII is the newer version of dex II. it's a gm thing even though with each new one they added a property.
DEXRON - Wikipedia, the free encyclopedia
what really matters is the about of lubrication(weight) and ep (amount of pressure the fluid can withstand before breaking down)
ratings each fluid maintains.
here is some good reading to wrap your head around it
1/2 way down the page
Automatic Transmission Fluid
or
read this copied from another forum.
The American Petroleum Institute (API) Service rating of a transmission oil refers to the amount of EP (extreme pressure) additives it contains. An API Service GL-1 oil contains no EP additives and a GL-4 Service oil contains about 1/2 the additives of of a GL-5 Service oil. EP additives are composed mostly of sulfur/phosphorus compounds that can harm yellow metals such as copper or brass that are contained in some synchros. Protege synchros do not contain yellow metals and consequently, as clearly stated in the M/T section of the FSM, either GL-4 or GL-5 oils are completely safe to use. The API Service rating is completely independent of the viscosity rating, so for example, an SAE 75W-90 oil could have a GL-4 or a GL-5 or even a GL-1 Service rating.
According to the Lubrizoil Corporation:
API Category GL-4 designates the type of service characteristic of spiral-bevel and hypoid gears in automotive axles operated under moderate speeds and loads. These oils may be used in selected M/T and transaxle applications.
API Category GL-5 designates the type of service characteristic of gears, particularly hypoids in automotive axles under high-speed and/or low-speed, high-torque conditions. Lubricants qualified under SAE J2360 also satisfy the requirements of the API GL-5 service designation.
In point of fact, API categories GL-1, GL-2, GL-3, and GL-6 were declared inactive (obsolete) by an SAE Technical Committee in 1995, although oils may still be marketed with these designations. Concomitantly, ASTM International (American Society for Testing and Materials) does not plan to maintain the performance tests associated with these categories, as in a number of cases these tests can no longer be run because parts or test installations are not available.
I assume most of you reading this want to upgrade from a mineral to a synthetic oil, so in addition to listing the transmission oil specs, I'll provide a partial list of what I believe to be fully synthetic oil alternatives. In order to qualify, the manufacturer must specify that it is derived from Group IV (PAO) or Group V (Polyol ester) base stocks. It is NOT enough simply to state that the oil is synthetic, fully synthetic or 100% synthetic. After all, Castrol Syntec claims to be fully synthetic, but we know it to be a hydrocracked mineral oil. I'll focus mostly on Red Line oil because not only is it my brand of choice, but more importantly, they provide more comprehensive data than can be found on other oil company websites.
Manual Transmissions (G15M-R)
The capacity is ~ 2.83 qts (2.68L). The FSM specifies SAE 75W-90 (all season) or SAE 80W-90 if the temperature never falls below 50 deg F (10 deg C). Suitable synthetic replacement oils are as follows:
Amsoil Synthetic Manual Transmission and Transaxle Gear Lube; SAE 75W-90, API GL-4, Product Code: MTG This is Amsoil's currently recommended oil for this application.
AMSOIL - Synthetic Oil, Motor and Engine Oil, Lubricants, Air Filters, Oil Filters and Greases
Fuchs-Silkolene: Silkolene Silktran SYN 5; SAE 75W-90, API GL-4/5. A fully synthetic M/T oil that, according to the manufacturer, is ideal for road and competition limited-slip differentials. May be used where conventional SAE 90, 85W-90 or 80W-90 lubricants are recommended.
Fuchs Silkolene Titan Oils & Lubricants
Fuchs-Silkolene is a British/German company. For a list of distributors in North America, go to:
FUCHS worldwide
Motul Gear 300 SAE 75W-90; API GL-5
Motul
Motul is a French company with many distributors in North America as a Google search will indicate.
Red Line MT-90 SAE 75W-90; API GL-4. According to Red Line, it has the appropriate coefficient of friction for most manual transmission synchronizers. Red Line claims that many gear oils, engine oils and ATFs are too slippery for proper synchro engagement.
Red Line Synthetic Oil
Torco RTF Racing Transmission Fluid: SAE 75W-90; SAE 80W-90; API GL-6. According to the manufacturer, this oil, derived from Group IV/V base stocks, is suitable for both racing and street use. As noted above, API GL-6 is an obsolete classification. It would provide a level of EP additive protection far in excess of anything our M/Ts currently require.
Torco USA
Automatic Transmissions (FN4A-EL)
The capacity is 7.6 qts (7.2L) after a complete fluid removal. The FSM specifies ATF type M-V or equivalent (e.g. Dexron III). Suitable synthetic replacement fluids are as follows:
Amsoil Synthetic Universal Automatic Transmission Fluid; replaces Dexron II and III, Mercon and Mercon V.
Red Line D4 ATF. Interestingly, this is a GL-4 rated oil, one of only two ATFs that I know of that are so rated. According to Red Line, D4 ATF is suitable for use where Dexron III, Dexron II, or Mercon fluids are recommended. It is also designed to satisfy the improved low temperature requirements which will be in the new Dexron IV specification and the improved shear-stability requirements which will be part of the new Mercon specifications.
Torco HiVis Automatic Transmission Fluid. According to the manufacturer, this oil, derived from Group IV/V base stocks, is suitable for both racing and street use. Meets all current Dexron and Mercon requirements as well as that of other types.
ATF in Manual Transmissions?
This is in reference to situations where the manufacturer does not specifically recommend its use. Apparently, some Forum members use ATF in their M/Ts. To begin with, I think it's a bad idea if for no other reason than it goes against OEM recommendations. Additionally, it's highly unlikely that ATF is an optimal lubricant for synchros which are absent from A/Ts. Recall that Red Line states that some ATFs may be too slippery for proper synchro engagement. Finally, I'm not sure if EP additives are even contained in most ATFs.
If you insist on using ATF, you might consider Red Line D4 or D6 as the best choice only because they're rated as GL-4 oils, one of the M/T oil requirements listed in the FSM. I'm not saying other ATFs aren't GL-4 or 5 rated, only that I have not yet found one listed as such.
Finally, there are other transmission oils marketed as synthetic but I have only listed here those that I believe are true synthetic oils.
Deletions:
Mobil 1 Synthetic Gear Lube LS 75W-90; API GL-5 and Mobil 1 Synthetic ATF have been removed from our list of M/T and ATF lubes believed to be fully synthetic. Discussions on the various oil forums and revised information on Mobil 1's website indicate that the oil is no longer derived solely from Group IV (PAO) base stocks but rather from hydrocracked Group III petroleum stocks with some PAO stock added as a finishing component to enhance overall performance. Thus, Mobil 1 is no longer considered a true synthetic by the standards we're applying here.
Red Line D6 ATF. It's designed to be a replacement for Dexron VI, Ford Mercon SP, Toyota WS, and Mercedes-Benz NAG-2 fluids. See posts #6 and #7 for explanation.
