After reading that wally world actually sources thier store brand stuff from some very reputible suppliers I have decided to give their gear oil a shot. Basicly Wally world motor oil is made by mobil and it is thier GRIII synthetic. Supertech Oil fileters are made by champion labs and are basicly identical to Mobil 1 and K&N filters at a fraction of the cost. Ect...
The subaru extra-s that came with the car was pretty good but got stiff in colder weather. It was sometimes difficult to shift into 1st gear. But overall a very good oil. My tranny was dropped recently (not too long ago) for a clutch change at a subaru dealership and they put in some new oil so the oil wasent too old when I switched over providing a better basis for comparison.
Im using Wally World brand 75w-90 GL5 Supertech Semi Synthetic Gear oil now. Walmart's source is actually Warren Distribution the manufacturers of MAG1 synthetic lubricants. The Spec is GL-5 and is also recommended for MT-1; MACK GO-J and SAE J2360 specifications.
The most telling is the MACK GO-J specification as it is the only specification that qualifies a mack truck transmission to qualify for an extended drain intervals. A mack GO-J specified oil is tested to exceed a baseline of antispalling, anticorrosion, and antiwear characteristics in a Mack T-200 series transmission with engine loads exceeding 1500ft/lbs of torque in heavy haul conditions.
This is a difficult specification to meet and MACK keeps a VERY short list (4 pages) of approved GO-J approved lubricants.
Surprisingly NONE of the deemed "high performance 15 dollar a bottle, 5 percent increase in horsepower!, passed our own arbitrary test, some guy online said it was the bomb! oils" are on it.
Here are some of the criteria.
Mack Power Divider Snap Procedure Specifications:
This procedure covers the Mack GO-J.
Objective The objective is to evaluate the wear protection of a
gear lubricant.
Procedure fixture
Mack truck tractor and trailer loaded to 98,000 lbs. are required to perform this procedure.
Procedure parameters
The Mack truck tractor and trailer are driven in a 100-foot diameter circle for 500 laps. Abnormal noise ("snapping", "popping", etc.) is noted and cams and wedges of power divider are rated for wear and distress.
Procedure parts evaluated
The cams and wedges are evaluated.
Pass/fail criteria
No "significant" distress present on parts and no
"abnormal" noise during testing are the pass/fail
criteria.
High-Temperature Cyclic
Durability Procedure (ASTM D5579)
Specifications
This procedure covers Mack GO-G, GO-H, GO-J,
Objective
The objective is to evaluate the thermal stability of
gear oils by determining number of cycles to unsynchronized shift.
Procedure fixture
Mack synchronizer with new friction and reaction
disks, oil heater, Mack T-2180 transmission, and
electric motor are required to perform this procedure.
Procedure parameters
The high-low range synchronizer of a Mack T-2180
18-speed transmission is shifted through a
12-second cycle (6 seconds in low range,
6 seconds in high range) until an unsynchronized
shift occurs. The shift pressure is held at 90 psi, the
procedure lubricant temperature is controlled at
250°F, and the tail shaft speed is held at 750 rpm
throughout the procedure. The countershafts speed
ranges from 459 rpm to 1756 rpm during the shift.
Procedure parts evaluated
The clutch disks, shifter fork, and synchronizer ring
are evaluated.
Pass/fail criteria
Number of cycles to failure greater than the average
of the last five passing reference oil results is the
pass/fail criterion.
So far so good. It actually felt better than the factory fill. Its pretty cheap too. If you don't like it you can always drain it out 4 qts cost me under 20 bucks.
Shifts are smooth. Actually a bit smoother than the extra-s. First gear is now slightly easier to shift into. There is less syncro "noise" (sometimes you can hear the syncros wind up when shifting from gear to gear). And overall shift effort has improved.
I will keep you up to date as to the longetivity of the oil.
Its had limited use on NASIOC but those that have tried it love it.
Could be an un-found diamond in the rough and a viable alternative.