Gear selector becomes very stiff and sometimes will not start in park or neutral

Transmission range switch could be the problem . Try placing gear selector into neutral when your having starting problem's. Some people call it a PNP switch - park neutral safety switch .

check the shifter mechanism for binding up and not moving freely into positions. Not starting in park but in neutral indicates something is out of alignment with the shifter. May just need cleaning and a bit of oil/grease to fix.

Test/Service/Replace

The circuit on newer cars with automatic transmissions has a neutral safety, or neutral start switch installed between the ignition switch and the starter. The ignition switch cannot operate the starter motor unless the transmission is in park or neutral.
Late model vehicles with manual transmissions have a starter/clutch interlock switch that requires the clutch to be depressed to the floor.
Neutral Safety Switch
Normal operations of a neutral safety switch provides a quick check for the adjustment of the gear selector linkage.

• To do this, move the selector slowly until it clicks into the PARK position.
• Turn the ignition key to the START position.
• If the starter operates, the PARK position is correct.
• After checking the PARK position, move the lever slowly toward the NEUTRAL position until the lever drops at the end of the NEUTRAL stop in the selector gate.
• If the starter also operates at this point, the gearshift linkage is properly adjusted.
• This quick test also tests the adjustment of the neutral safety switch.
• If the engine does not start in either or both of these positions, the neutral safety switch or the gear selector linkage needs adjustment or repair.

CAUTION
Since you must work under the vehicle to adjust most shift linkages make sure you properly raise and support the vehicle before working under it. Also, wear safety glasses or goggles while working under the vehicle.
A voltmeter can be used to check the switch for voltage when the ignition key is turned to the START position with the shift lever in PARK or NEUTRAL. If there is no voltage, the switch should be adjusted or replaced.

The Neutral Safety switch monitors the position of your gear selector lever and either interrupts or allows the starting circuit in your car or truck to do its job. On newer vehicles it may also monitor the position of the brake pedal to make sure that the vehicle is in park or neutral AND that your foot is on the brake.

If your vehicle is equipped with a neutral safety switch, it should NOT start UNLESS the transmission is in Neutral or Park. On the other hand your vehicle SHOULD start when it is in Neutral or Park. If your car will start in Neutral but not in Park, you have a bad switch. Also, if your car or truck will only start by turning the key to the start position and wiggling the gear selector lever, your neutral safty switch is in need of replacement.

The nuetral safety switch is usually found near the gear shifter. If your car has the gear shift on the column, then the neutral safety switch is usully mounted on the steering column near the brake pedal. On floor mount or console mount vehicles you will find the nuetral safety switch mounted near or on the shifter mechanism.

I would look at the operation and/or adjustment of the gear selector and the transmission range sensor (often mistakenly referred to as a 'neutral safety switch").

I say adjustment because the Neutral gate is mid-range of the selector, while the Park gate is at one end of the range. Thus, if the selector mechanism and the sensor position are not properly aligned, the sensor amy more accurately report the Neutral gate than the Park gate, resulting in cranking in the Neutral position but not while in Park.

Do you sometimes have to wiggle the shifter in Neutral to get it to crank?

The backup lamps will light whenever the ignition switch is in the RUNposition and the transaxle is in REVERSE. On older vehicles, this function was handled by a dedicated switch with a name such as the Neutral/Safety Backup Light Switch, or something similar. This switch was designed to keep the engine from starting in any gear except PARK and/or NEUTRAL. The switch contacts also activated the backup lights when the transaxle was placed in REVERSE.

On the vehicles covered by this manual, the backup lamp control function is part of an integrated switch called the Transaxle Range switch (sometimes also called the Park/Neutral Position or PNP switch). In addition to turning on the backup lights, the Transaxle Range switches primary function is to transmit to the Powertrain Control Module (PCM) the driver's transaxle range selection. The PCM uses this information to control both engine and transaxle functions electronically.

The Transaxle Range switch is mounted externally on the transaxle. New service replacement switches come pinned in the NEUTRAL position and no adjustment should be necessary. Please note that if the switch requires adjustment, GM recommends that their special tool J 41545 Park/Neutral Switch Alignment Tool be used to properly adjust the Transaxle Range switch, if required.

Removal & Installation

1. Apply the parking brake and block the front wheels.
2. Place the transaxle gear selector to NEUTRAL.
3. Remove the air intake duct to access the switch located on the top of the transaxle at the range selector cable and arm.
4. Disconnect the transaxle range selector cable.
5. Detach the electrical connectors from the range selector switch.
6. Remove the range selector lever retaining nut and lift off the lever.
7. Unfasten the range selector switch mounting bolts, then remove the switch from the transaxle manual shaft.

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You should either check the neutral switch on the column inside by the base or the steering wheel or replace it. Sounds like it maybe shorting out or a wire is pinching.

Your safety interlock switch is going out or is not adjusted properly. There is a procedure for adjusting the switch. The switch is on the transmission in the engine compartment. If you want to adjust the switch, loosen the botls holding the switch and follow steps 7-8 below. Else, you can just replace the switch entirely by following all steps.

The neutral start and backup switch are one unit mounted on the top left end of the transaxle. The neutral start portion of the switch allows electrical current to travel to the ignition system when the shift selector is in park or neutral only. The vehicle will not start when the selector is in any other gear. The backup portion operates the rear backup lamps when selector is in the reverse gear.

REMOVAL & INSTALLATION See Figures 1 and 2

1. Make sure the shift selector in the Park position, then apply the emergency brake.
2. Disconnect the negative battery cable.
3. Disengage the neutral start switch electrical connector, then remove the shift control lever on top of the switch.
4. Remove the two neutral switch attaching bolts, then remove the switch.

Fig. Fig. 1: Neutral safety switch location-vehicles equipped with automatic transaxle

Fig. Fig. 2: Adjusting the neutral safety switch

To install:

1. Install the switch on the manual shaft.
2. Loosely install the two attaching bolts and washers.
3. Insert a No. 43 drill (0.089 in.) through the hole.
4. Tighten the attaching bolts to 7-9 ft. lbs. (9-12 Nm), then remove the drill.
5. Engage the switch electrical connector, then connect the negative battery cable.

neutral safety switch is out of adjustment

I had the same problem and I fixed it by oiling the gear shaft beside the transmission tank. There is no taking apart anything in the transmision but instead the shaft that is visible under the car I oiled.