Technical Service Bulletin Transmission Jumps Out Of 1st or 2nd Gear

Subject: Transmission Jumps Out Of 1st or 2nd Gear Models: 911 Carrera 1987

Bulletin Number: 87 – 05

Model Year 1987

(type 950 transmission)

The 4th gear sliding sleeve (1 in picture 1) and the guide sleeve (2 in picture 1) were modified to prevent the 4th gear from moving back into the neutral position while driving.

The groove around the inside of the sliding sleeve has been omitted. Instead, three pockets are machined on the inside of the sleeve. Also, the new guide sleeve is coated with a sliding lubricant.

From production Dates:

                January 13, 1987 sliding sleeve

                January 21, 1987               guide sleeve

Transmission numbers:

                950/01 74 H 045671        sliding sleeve

                950/01 74 H 4834             guide sleeve

Part numbers:

928.304.231.06                  sliding sleeve     3rd-4th gear

930.304.221.06                  guide sleeve       3rd-4th gear

Work procedure:

In case of complaints of jumping out of 4th gear while driving, first check the shift rod adjustment as follows:

  1. Lift shift diagram cap off shift lever knob.
  2. Unscrew shift lever knob allen screw and pull off knob.
  3. Dismantle center console, slide over shift lever and put aside (electrical equipment remains connected).
  4. Measure distance between shift base bushing and shift lever with 4th gear engaged. Should be 5mm (picture 2). If necessary, loosen shift base bolts and move shift base to obtain correct adjustment. Torque bolts to 23 Nm (17 ft. lbs.).
  5. Reinstall center console and shift knob.

If no improvement, install both new type sleeves.

Note: Punch marks on the level end of the sliding sleeve (3 marks) must be aligned with balls of the guide sleeve.

Important Notice: Technical Bulletins are intended for use by professional technicians, not a “Do-it-yourselfer”. They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Special tools may be required to perform some of the operations identified in these bulletins. Use of tools and procedures other than those recommended in these bulletins may be detrimental to the safe operation of your vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your Porsche Dealer for information on whether your vehicle may benefit from the information. Part numbers listed in these bulletins are for reference only. Always check with your authorized Porsche dealer to verify correct part numbers.

home page:

Want More?

Get the coolest tips and tricks today

Subscribe to our email list and get regular notifications of new videos and blog articles on how to repair your own car.