News Technical Service Bulletins

Bad Tone Wheel Knocks Ram Off Track

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KEYWORDS Mitchell 1 Ram
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Example of missing magnetic material on a tone wheel.

This bulletin applies to 2014-2018 RAM 1500 trucks equipped with a 3.0L V6 turbo diesel engine, built on or after June 13, 2014, and on or before March 26, 2018.

Customers may experience a warning light on. diagnostic trouble code (DTC) P0335-00 (crankshaft position sensor circuit) and/or P0336-00 (crankshaft position sensor performance) may be set. The customer may note that the vehicle will not accelerate quickly beyond 50 mph (limp mode), and there may be periodic stalling.

The symptom is caused from missing magnetic material on the crankshaft tone wheel. Remove the transmission. Paint a match mark on the flexplate hub to the flexplate for future reference. Caution: Do not use an impact socket or thick-walled socket when removing or installing the flexplate bolts, as this may damage the crankshaft causing the internal engine and/or transmission damage.

Remove the flexplate mounting bolts and flexplate. Discard the flexplate bolts. Remove the counterweight and tone wheel.

Install a new tone wheel P/N 68493358AA. Make sure that the dowel pin is installed in the dead hole of the counterweight. The other hole is a through hole and is not to be used. Install the counterweight and make sure that the dowel pin side is inserted into the crankshaft hole for proper counterweight timing. A vibration can occur if installed incorrectly.

Install the flexplate, backing plate and eight new bolts P/N 68161231AA. Always use new flexplate bolts. Do not lubricate the bolts, as they are already coated with an anti-scuff treatment. Use clean engine oil to lubricate the bolt side of the backing plate.

Use the correct bolt tightening sequence, torquing bolts to 37 ft-lbs. Then, loosen one bolt at a time and then retighten the bolt in a clockwise cross pattern to 92 ft-lbs. Once all bolts have been torqued, tighten each bolt by an additional 30 degrees in a clockwise criss-cross pattern.

Reinstall the transmission, clear any DTCs and road test.

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1) Flexplate bolt; 2) Backing plate; 3) Flexplate; 4) Counterweight; 5) Tone wheel.

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Note the counterweight dowel pin position.

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Note the flexplate bolt tightening sequence. These are torque-plus-angle bolts. Torque all to 37 ft-lb, then loosen and re-torque one at a time to 92 ft-lb, then angle tighten by 30 degrees.

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