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cbetts -> RE: 5 Speed Manual Trans a Box of Rocks (4/18/2008 5:46:11 AM)
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Oops, Looks like I linked wrong . . . here is the text from their document:
quote:
2008 Aisin AR-5 (MA5) Car And Truck Transmission
2008 Model Year Summary
Aisin AR-5 (MA5) five-speed manual car and truck transmission
Carryover from 2007 Model Year
o Ratio For 3rd Gear Higher For Pontiac Solstice And Saturn Sky
o 1st And 3rd Gears Strengthened With Shot Peening Process
o Clutch Made Larger For Hummer H3 Application
o 2nd And 3rd Gear Synchronizers Changed To Carbon On H3 Application
FULL DESCRIPTIONS OF CARRYOVER FEATURES
RATIO FOR 3RD GEAR HIGHER FOR PONTIAC SOLSTICE AND SATURN SKY
The ratio for 3rd gear on both roadsters was made “shorter”, or higher, to allow higher engine rpm for better performance in 3rd gear and bring it closer to 2nd gear. This change is not applied to the compact pickup trucks, Chevrolet Colorado and GMC Canyon.
1ST AND 3RD GEARS STRENGTHENED WITH SHOT PEENING PROCESS
The 1st and 3rd gearsets on the Solstice and Sky, and the Hummer H3, are strengthened by a shot peening process during gear manufacturing. The increase in torque from the new high-performance 2.0L I4 turbocharged engine in the Solstice GXP and the Sky Red Line, as well as in the new 3.7L I5 in the H3 required the stronger gears.
CLUTCH MADE LARGER FOR HUMMER H3 APPLICATION
To handle the increased power and torque from the new 3.7L I5 in the Hummer H3, the clutch was increased in diameter from 265mm to 280mm.
2ND AND 3RD GEAR SYNCHRONIZERS CHANGED TO CARBON ON H3 APPLICATION
The friction material on the synchronizers for the 2nd and 3rd gear blocker rings are changed from brass to carbon, which is a more durable and heat-resistant material. This allows the transmission to handle the increased torque of the new 3.7L I5 in the H3.
LOW MAINTENANCE
The Aisin AR-5 uses Esso 75W90 for lubrication. There is no maintenance required under normal operating conditions, although fluid changes are recommended for severe duty. A GM part number service oil is available from GM dealers.
OVERVIEW
To achieve car-like standards in running noise and shift quality, the proven Aisin AR-5 was selected for the Chevrolet Colorado and GMC Canyon (GMT355) compact pickup truck line. This transmission will handle the torque output of the base and uplevel engines, which will reduce assembly and service complexity.
The design and performance targets were supplied to Aisin by GM Powertrain to make the AR-5 a state-of-the-art manual light-duty transmission. The AR-5 is currently used by Isuzu and Toyota, although the gearsets and ratios for the GM application are unique.
The Aisin AR-5 was selected as a starting point because of its characteristic low-noise levels during operation and the light shift feel and smooth gear engagement properties. The Aisin unit is used in competitive sport-utility applications, meeting car-like noise standards.
The Aisin 5-speed transmission is a conventional two-axis manual gearbox, with a through shaft and a counter shaft, spaced 82mm apart on-center. It is cast in aluminum, and weighs 107 pounds. The gear selector pattern is conventional for a five speed manual transmission, with the reverse gate on the far right side and rearward. The shift lever connects directly to the top of the transmission.
Triple-cone synchronizers are used on 1st, 2nd and 3rd gears. These synchronizers have three friction surfaces, which increase their ability to transfer the flow of torque more smoothly from one gear to another. Synchronizers act as clutches to speed up or slow down the gearsets that are being shifted to, and greater friction area results in easier shifting for the driver. All of the friction surfaces on the synchronizer rings are brass. The ratios in the 5-speed are widely spaced in the pickup truck applications for versatile performance and efficiency, and ar
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