M/T - Noise/Hard To Shift Into 3rd Or 4th Gear
Bulletin No: 05-002/10Last Issued: 01/29/2010
Subject:
GEAR NOISE AND HARD SHIFTING INTO THIRD OR FOURTH GEAR
APPLICABLE MODEL(S)/VINS
2009-2010 Mazda6 with 6-speed M/T (G66M-R)
2010 Mazda3 with 6-speed M/T (G66M-R)
DESCRIPTION
Some customers may complain about a gear noise and/or hard shifting into third or fourth gear on the 6-speed M/T because the third or fourth gear synchronizer ring may be worn excessively. One of the causes of synchronizer ring wear is driving the vehicle in neutral gear for fuel economy, called Neutral driving." When acceleration is then needed, the driver must shift into a gear from neutral. In such a situation, it is easy to cause damage to the synchronizer ring because of the difficulty to synchronize engine speed and gear speed for engagement. Third gear has been modified since lot 8**0311610; Lot number is as follows:
Customers having this concern should have their vehicle repaired using the following repair procedure.
REPAIR PROCEDURE
1. Verify customer concern.
2. Replace the 3rd and 4th synchronizer rings with modified parts. If the parts related to the 4th gear are damaged (such as gear and hub), replace with new ones.
3. Verify repair.
EXPLANATION TO CUSTOMER
If the customer seems to drive with the vehicle in neutral gear (coasting along flat roads or downhill with the transmission in neutral), explain the following to the customer.
Do NOT drive with the vehicle in neutral gear - it does not help fuel economy. Despite being in neutral gear, fuel keeps going to the engine while it is running. Taking your foot off the accelerator pedal is much more helpful to fuel savings rather than driving in neutral gear because the Mazda engine management system stops fuel to the engine when the throttle valve is closed. For instance:
Case A: The vehicle is moving with the transmission in neutral gear while taking your foot off the accelerator pedal => Fuel keeps going the the engine to run it at idle speed, let's say, 750 rpm.
Case B: The vehicle is moving with the transmission in any gear while taking your foot off the accelerator pedal => Fuel is stopped from going to the engine despite the engine speed indicated, let's say, 1500 rpm.
As you can see, Case B is much more beneficial than Case A. From other technical stand points, frequently driving in neutral gear may reduce the service life of the clutch and brakes. Driving down a slope while using engine braking" stops fuel to the engine and gives you seamless vehicle speed control, which reduces clutch and brake operation. Therefore, this type of driving style helps not only fuel economy, but also extends the life of service parts.
Mazda recommends driving suggestions to save money in the owners manual [BEFORE DRIVING YOUR MAZDA]. These tips are beneficial for economy, safety and environmental protection.
PART(S) INFORMATION
WARRANTY INFORMATION
NOTE:
^ This warranty information applies only to verified customer complaints on vehicles eligible for warranty repair.
^ This repair will be covered under Mazda's New Vehicle Powertrain Limited Warranty term. Additional diagnostic time cannot be claimed for this repair.
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