Hello all -
I'm changing out the rear diff fluid in my '97 Mazda MPV 2WD, and manual transaxle fluid in my '09 Mazda 5.
The MPV specs GL-5 80W if temperature will be < 0 F (-18 C), and 90 otherwise. Not wanting to do seasonal changes, I'll picked up some AMSOIL synthetic gear lube in 75W-90, rated GL-5. No controversy there.
The MT fluid for the 5 is a bit trickier. I would like to use the same fluid but understand that the GL-5 should not be used in an MT rated for GL-4; apparently some of the GL-5 additives can damage the yellow-metal synchro gears.
The owner's manual for the 5 states that GL-4 or GL-5 is acceptable. 75W-90 is recommended for year around use, and 80W-90 for temperatures > 50 F (10 C). So far so good ...
However, the factory service manual for the 5 has a range of VIN numbers for which GL-4 or GL-5 can be used, and a range for which only the GL-4 can be used. My vehicle's VIN indicates that GL-4 or GL-5 will be OK. Interestingly, the higher VIN range is for GL-4 only.
1st question: Would it be better to go with a GL-4 fluid to be absolutely safe?
2nd question: I notice that AMSOIL does make a dedicated GL-4 MTF in 75W-90. Would this be a better choice than the GL-5 general purpose 75W-90 gear lube in a manual transaxle?
Bear in mind MTF is hard to find up here. If I'd seen it in the shop where I bought the gear lube, I would have chosen it for the MTF instead.
Thanks in advance for your feedback!
I'm changing out the rear diff fluid in my '97 Mazda MPV 2WD, and manual transaxle fluid in my '09 Mazda 5.
The MPV specs GL-5 80W if temperature will be < 0 F (-18 C), and 90 otherwise. Not wanting to do seasonal changes, I'll picked up some AMSOIL synthetic gear lube in 75W-90, rated GL-5. No controversy there.
The MT fluid for the 5 is a bit trickier. I would like to use the same fluid but understand that the GL-5 should not be used in an MT rated for GL-4; apparently some of the GL-5 additives can damage the yellow-metal synchro gears.
The owner's manual for the 5 states that GL-4 or GL-5 is acceptable. 75W-90 is recommended for year around use, and 80W-90 for temperatures > 50 F (10 C). So far so good ...
However, the factory service manual for the 5 has a range of VIN numbers for which GL-4 or GL-5 can be used, and a range for which only the GL-4 can be used. My vehicle's VIN indicates that GL-4 or GL-5 will be OK. Interestingly, the higher VIN range is for GL-4 only.
1st question: Would it be better to go with a GL-4 fluid to be absolutely safe?
2nd question: I notice that AMSOIL does make a dedicated GL-4 MTF in 75W-90. Would this be a better choice than the GL-5 general purpose 75W-90 gear lube in a manual transaxle?
Bear in mind MTF is hard to find up here. If I'd seen it in the shop where I bought the gear lube, I would have chosen it for the MTF instead.
Thanks in advance for your feedback!