Vulcaneer wrote:
ib516 wrote:
It was a 3500 SRW 4x4, laramie, crew cab, and it was equipped with 3.42 rear axle, the 850tq Cummins, and the Aisin 6 speed auto.
Rpm @ 72 mph was ~1500.
I guess I would question the gearing. Seems pretty high? Assuming it develops peak torque at 1600 RPM, at 65 MPH (highway speeds) it would be below peak torque. Not a problem for non towing. But if towing medium/heavy (say 14,000 LBS), do you think it would be shifting a lot when encountering slight grades at 65MPH?
I would think a bit lower gear might be better for heavey towing.
What is the Aisin 6th gear ratio compared to the Dodge 6 speed auto.
Appears the 3.42, 3.73 and 4.10 gears are available. I would get 3.73 or 4.10 depending on 6th ratio. I am not sure the ratios are the same on the one in a Ram Pickup verses the CC. However with a .63 6th gear I would get the 4.10's and pull houses over.
Aisin Seiki Six-Speed AS68RC (Dodge Cab and Chassis Only)
Specifications:
First gear: 3.74 n Second gear: 2.00
Third gear: 1.34 n Fourth gear: 1.00
Fifth gear: 0.77 n Sixth gear: 0.63
Reverse: 3.54
Weight: 348 pounds (dry)
ATF lube capacity: 14.79 quarts
Torque converter: 12.2-inch diameter with four-disc converter
Input shaft diameter: 1.06 inches
Output shaft diameter: 1.68 inches
Allison Vs Torqshift Vs Aisin Allison 1000 Transmission
Allison 1000 (GMC and Chevrolet)
Specifications:
First gear: 3.10
Second gear: 1.81
Third gear: 1.40
Fourth gear: 1.00
Fifth gear: 0.71
Sixth gear: 0.61
Reverse: 4.49
Weight: 330 pounds (dry)
ATF lube capacity: 12.68 quarts
Torque converter: 12.2-inch diameter, dual-friction, single-disc converter
Input shaft diameter: 1.26 inches
Output shaft diameter: 1.75 inches
Allison Vs Torqshift Vs Aisin Ford 6R140 Torqshift Transmisson
Ford 6R140 TorqShift
Specifications:
First gear: 3.97
Second gear: 2.32
Third gear: 1.52
Fourth gear: 1.15
Fifth gear: 0.86
Sixth gear: 0.67
Reverse: 3.13
Weight: 325 pounds (dry)
ATF lube capacity: 16.7 quarts
Torque converter: 12.60-inch diameter, 2-disc converter
Input shaft diameter: 1.18 inches
Output shaft diameter: 1.61 inches
With 4.10's and a .69 OD in my truck I am turning 62-63 MPH at 2000 RPM this should be around 1800 or so. So Towing it Calif in 5th gear would about right. 3.42 are just to tall. I could settle for 3.73 but not 3.42's.
Chris