Minor Transmission and Drivetrain
Overdrive (M41) Failure
Symptoms
Overdrive won't engage, engages but kicks out under load, grinds or whines.
Cause
The overdrive unit bolted to the back of the M41 gearbox is electrically actuated. Solenoid failure, worn clutch pack, low oil level, or internal mechanical wear all cause problems.
Fix
Check the simple stuff first: fuse, relay, wiring to the overdrive switch on the gearbox.
Test the solenoid.
If the overdrive unit itself is faulty, it's a strip-down job, clutch plates, springs, and one-way bearings can all wear out.
Ensure the gearbox and overdrive have the correct oil level (often overlooked).
Know something we don't?
Owned a Volvo 164? Share your experience with this issue. What worked, what didn't, costs, tips. Help the community.
Submit an update