chatter or vibration 42 to 45 mph in od on 1994 Dodge Ram 2500

when driving with no load

1 answer
There is a Technical Service Bulletin to address a similar issue.
NO: 21-04-95
SUBJECT: Vibration or Perceived Engine Miss
DATE: Apr. 14, 1995
NOTE: THIS BULLETIN APPLIES TO VEHICLES EQUIPPED WITH THE CUMMINS DIESEL ENGINE AND AUTOMATIC TRANSMISSION.

SYMPTOM/CONDITION:
A vibration or perceived engine miss at approximately 1100 RPM as the torque converter clutch engages. This condition occurs in 4th gear at speeds between 42 to 48 MPH.

DIAGNOSIS:
After duplicating the above condition, verify the part number on the Powertrain Control Module (PCM). For proper repair procedure, refer to the guidelines given below.
If the vehicle is a 1994 MY equipped with PCM P/N 56027303 or 56027304, replace the PCM with P/N 4798745. Proceed to the PCM replacement section of this TSB.
If the vehicle is a 1995 MY, verify that it is equipped with PCM P/N 56028335 or 56028336, and proceed to the PCM reprogramming section of this TSB.
If the vehicle is equipped with a PCM other than 56028335, 56028336, 04798745, or 04856080, replace the PCM with P/N 4798745 and proceed to the PCM replacement section of this TSB.

NOTE: IF THE VEHICLE IS EQUIPPED WITH PCM P/N 4798745 OR 4856080, THE SOFTWARE UPDATE NEEDED TO ADDRESS THIS TSB ISSUE HAS ALREADY BEEN COMPLETED AND NO FURTHER ACTION IS REQUIRED.

PARTS REQUIRED:
Quantity
Part No.
Description

(1) 04798745 Module, Powertrain Control (1994 Only)
(1) 4669020 Label - Authorized Software Update
(1) 4275086 Label - Authorized Modification