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  • Suggested articles, sometimes including step-by-step procedures, are indicated with orange colored text. You can also submit YOUR Opel TechTips, for consideration by the Editor of the OMC Blitz, to: joinomc@opelclub.com
  • The most common cause of Opel transmission failure, is internal burn-out following oil leaks, caused by improper installation. Regularly check fluid levels, and regasket and re-seal transmissions when there are known leaks. If a "thump" is felt when accelerating from a stop, inspect or replace the torque tube "donut" bushing and upper stop, and if a "howl" is heard at 40-50 miles per hour, inspect the differential and refill to proper level with 140 weight gear oil. Available transmission upgrades include the bolt-on European GETRAG 5-speed, for quieter, improved performance at highway speeds.

How to Order: Reprints of Individual OMC Blitz issues, can be ordered by mail from the OMC Treasurer (3824 Franklin Ave, La Crescenta CA 91214) for $2.00 each (cost includes postage). This offer is subject to availability.

Mar - Apr 2008

Opel GT transmission conversions, to original 4 speed manual and to original automatic - Download here

July/Aug 2007

Opel Clutch Fork & Clutch Cable Adjustments (1 page, illustrated)

May/June 2007

4-speed Shift Knobs (1 page, illustrated) Compares 1968-1972 GT, 1973 GT, and Mantas

May/June 2007

5-speed GETRAG "Short Shifter" modification (3 pages, illustrated)GT, Manta & Kadett B

May/June 2007

5-speed GETRAG shifter modifications (5 pages, illustrated) Separate sections for GT & Manta

Sept 2002

Transmission Synchro, 1 page
Synchro interchange, between Opel 4-speed and Fiero 5-speed.

Sept 1998

Clutch cable breaking, 1 page (illustration)
Dennis G. urges inspection, and if necessary repair, of cable hook area at top of clutch pedal.

March 1998

Clutch slipping, 1 page
Mentions to check clutch cable adjustment first, before pulling clutch.

March 1998

Transmission Fluid Loss, 1 page
Response is the most common cause (in a 4 speed manual transmission) is improper installation of the "front gasket" between bellhousing and trans, usually caused by not using gasket sealer and not tightening the lower passenger-side bolt. Where leaks exist, trans should be re-gasketed and resealed properly, as running without oil will burn out the 4th gear synchro.

Feb 1998

Internet tech tips: clutch e-clip replacement, 1 page
Suggests locating a 1" wide heater hose clamp behind the "e-clip" at the firewall on the clutch cable, to help prevent the e-clip from popping off, and to use as a backup (in an emergency). Vice Grips will also do in an emergency.

Jun 1997

Draining the differential, 1/4 page
Gil W. suggests removing lowest bolt, to drain rear axle oil.

Oct 1996

Clutch cable repair; 1/2 page
Russ S. suggests to cover split cable housing, with 3/4" heat shrink tubing.

Feb 1996

Clutch Cable E-Clip replacement

Dec 1995

Draining gear oil from 1971-75 4-speed gearboxes

Dec 1995

Removal of gearbox to bellhousing bolts

Aug 1995

Opel 5-Speed Transmission Installations "A Very Good Gear"; 2 pages illustrations)

Aug 1995

U-Joint Angles; 1 page (illustration)

March 1995

Clutch/Transmission Tech Tips; 1 page (illustrations)

March 1995

Transmission Shifter Shaft Seal Replacement Tip; 1 page (illustration)

March 1995

Converting a GT to a Manual Transmission, List of Parts Required; 1 page

March 1995

Converting a GT to an Automatic Transmission, List of Parts Required; 1 page

Aug 1992

Clutch Cable Installation; 1 page (illustration)

March 1991

Lightened Flywheel (Letter & Reply); 1 page

March 1990

Lightened Flywheel for the 1.9 Liter Engine Tips; 1 page (illustration)

April 1989

Reply to Letter about Rear Axle Noise Diagnosis, 1 page
Describes conditions possible to diagnose rear axle noise; Noises only on turns indicates worn axle or carrier bearings, high pitched whine starting at very low speeds  indicates worn pinion bearings, and a noise when coasting 40-50mph (in neutral, with no acceleration) indicates worn ring and pinion gears.

April 1989

Reply to Letter Comparing Chevy Vega/Luv  to Opel Transmissions; 1 page
Notes that the Chevy/Isuzu 4 speed manual transmission will not bolt into an Opel, but that some internal components will swap over to Opel.

April 1988

Gear Oil Change, Transmission & Rear Axle; 1 page
Roger L. suggests Kendall 80-85-140W "three star"gear oil, and states that removing the lower center bolt is the best method of draining the rear axle, while removing the oil pan is the best method of draining oil from the 1968-1970 "early style" Opel manual transmission. (The later 1971-1975 Opel manual transmissions can be more easily drained by unscrewing and removing the cylindrical rear-mounted reverse switch.  Oil refill capacity for the rear axle is 2 1/4 pints, and another 2 1/4 pints will refill the manual transmission.

Dec 1986

Torque Tube Upper Bumper Tip, 1 page (illustrated)
Roger L. suggests installing a front suspension bump stop bushing (cut back about 1/2") at top of torque tube 'donut' for better torque joint.

Dec 1986

Bellhousing Part Tip (GT & Manta's Not Interchangeable); 1 page
Rick G. notes that the bellhousing from a manual transmission Manta/Ascona will not work in a GT, as the angle of outlet for the clutch arm is different, and the cable connection will jam the end of the arm into the tunnel area.

Dec 1985

Gearshift Rattle at High RPM's Solution; 1 page
Notes the internal reverse actuator cable needs adjustment, to stop gear knob rattle.

Nov 1985

Transmission & Clutch Replacement Tips; 1 page
Tom E. suggests replacing the front transmission seal, transmission-to-bellhousing gasket, and pilot bearing during a clutch job.

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