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Chrysler TorqueFlite A518 Automatic Transmission

TorqueFlite A518 Specs, Ratios, & Information

The Chrysler TorqueFlite A518 represents the movement towards more advanced overdrive transmissions based on the company's flagship TorqueFlite 727. With the addition of a 0.69 to 1 overdrive ratio, Dodge achieved greater fuel economy and practicality in 1st Gen Dodge D250/350 and W250/350 models. The transmission was short-lived in Dodge Cummins applications as a more robust unit was required for the p-pumped 12 valve Cummins found in 2nd Gen Ram 2500 and 3500 models. However, the A518, renamed the 46RH at some point in or near the 1992 model year, would see continued service in a number of Dodge and Jeep vehicles.

The A518 is slightly longer than the 727 as a result of the overdrive unit mounted in the tailhousing. Overdrive engagement and torque converter lockup rely on electronic solenoids while the 1, 2, 3 shift sequence is controlled entirely by hydraulic governor pressure. Due to the electronic OD and lockup, an electronic control module - single module engine controller, or SMEC - is required for proper function of these systems. An easy way to distinguish an A518 from an earlier 727 is to look for an electrical connector on the driver side of the transmission; the A518 will have one, while the 727 will not.

Chrysler A518 Transmission Specs & Ratios

Type:

4 speed overdrive, automatic

Applications:

1991 - 1993 Dodge D250, D350, W250, W350
Introduced mid-model year for 1991

Predecessor:

Chrysler TorqueFlite 727, 3 speed automatic

Case Material:

Cast aluminum with integrated bellhousing

Case Length:

~ 37 inches

Weight:

~ 170 lbs

1st Gear Ratio:

2.45 : 1

2nd Gear Ratio:

1.45 : 1

3rd Gear Ratio:

1.00 : 1

4th Gear Ratio (OD):

0.69 : 1

Reverse Ratio:

2.35 : 1

Fluid Type:

MOPAR ATF+4 automatic transmission fluid [1]

Fluid Capacity:

14.5 - 16.5 quarts total capacity, ~4.0 quarts service refill capacity

Filter P/N:

MOPAR 3515996

Fluid Pan Gasket P/N:

MOPAR 0246 4324AC

Service Intervals [2]:

Replace transmission fluid and filter every 30,000 miles
Adjust bands every 24,000 miles/24 months

Features:

• Based on Simpson planetary gearset design

• Electronically controlled torque converter lockup

• Electronically controlled overdrive

• Four speed derivative of the Chrysler TorqueFlite 727

• Referred to as the 46RH after 1992 when Chrysler's transmission model designation format was changed

Identification:

Chrysler A518 transmission pan ID

[1] MOPAR ATF+4 supersedes all previous (and defunct) automatic transmission fluid specifications
[2] Service intervals as identified by the 1991 - 1993 Dodge service manual; recommend servicing transmission at band adjustment intervals for convenience.