Running better with the M50D
Thread Starter
|
Senior User
Joined: Jul 2003
Posts: 318
Likes: 0
From: North of Toronto, Ontario
Running better with the M50D
Last weekend I swaped out the old 4 speed O/D tranny for the Mazda 5 speed. Filled her up with Synthetic fluids. Also swaped out the old driveshaft for the newer styled aluminum one. Man does the truck move better now. Befor I had troubble getting her up to 3000 RPM in O/D. Now I'm there before I now it and it wants to keep goin!!!
Is the O/D gear the same ratio in these two trannys? If so, what is making her run better? Less loss through the tranny, or does the new driveshaft have something to do with it?
I think my speedo might be a little off also. How fast was i going? I was up to 3100 RPM. Mazda 5 speed in 5th, 3.55 rear gears, and stock 235/75R15 tires.
Is the O/D gear the same ratio in these two trannys? If so, what is making her run better? Less loss through the tranny, or does the new driveshaft have something to do with it?
I think my speedo might be a little off also. How fast was i going? I was up to 3100 RPM. Mazda 5 speed in 5th, 3.55 rear gears, and stock 235/75R15 tires.
Post Fiend
Joined: Jan 2000
Posts: 5,860
Likes: 4
From: Metro Detroit (Redford)
Running better with the M50D
FWIW: Don't know what year your truck is, but my '84 has a 4 speed that has 0.71 OD ratio (3.01, 1.78, 1.00, and 0.71); whereas my '95 has the Mazda 5 speed with 0.80 OD (3.90, 2.25, 1.50, 1.00, 0.80). My '95 has 3.08 rears vs the '84's 2.47, so second in the '95 is like first in the '84 and OD in the '95 is like third in the '84. The '95 with 235/75/15 tires in OD goes 70 mph turning in the neighborhood of 2000 - 2100 RPM. (The '84 at that speed would have been turning around about 1600 - 1700 and couldn't run OD with a headwind.)
Posting Guru
Joined: Apr 2003
Posts: 1,153
Likes: 1
From: Venezuela
Running better with the M50D
Over Drive ratio for AOD trans. depends on year model, older was about 0.64:1 newer is 0.70:1
My actual AOD is 0.64 + 3.55 + tires 235/75R15 and it gives 120Km/h @ 2.050RPM
Hope it help you. Regards;
My actual AOD is 0.64 + 3.55 + tires 235/75R15 and it gives 120Km/h @ 2.050RPM
Hope it help you. Regards;
Thread Starter
|
Senior User
Joined: Jul 2003
Posts: 318
Likes: 0
From: North of Toronto, Ontario
Running better with the M50D
Thanks but my tranny is not an AOD, it's a M5OD (Mazda 5 speed Manual), and the one it replaced is a 4 speed OD manual. Back many years age when I bought the truck, it had the E4OD automatic - lasted me 10000 km. I will NEVER NEVER EVER own another automatic. Thanks for the reply though anyway.
Posting Guru
Joined: Jun 2002
Posts: 1,288
Likes: 1
From: redding U.S.A.
Running better with the M50D
i have the same gear set up as you and i think that at 3k in over drive its goin more than 75mph with 31" tires. It sucks for highway use, as i see that as the top end of the motor.
