Test Driving Manual Transmission

Test driving manual transmission

Background
In case of customer complaints about gear change quality or noise from the transmission, the test driving schedule in this Service Bulletin can be used for fault-tracing, the correct diagnosis and service corrections. This applies to all Volvo 850/C70/S70/V70 with manual transmissions.
Form TP 48253-1 "Diagnosis for manual transmission" should be used with the test driving schedule.

Preparations:
Check the transmission oil level before test driving. To achieve the normal transmission operating temperature and ensure that the aluminum transmission housing is at the correct temperature, the car should be driven for approximately 20 minutes before the road test begins.
Note the car registration number, mileage, transmission P/N and serial number.

Test:
- Stationary with engine idling, clutch pedal completely depressed and gear selector lever in neutral position. Release the clutch, listen for mechanical noise, and if the noise occurs with the clutch pedal depressed or released. Repeat 10 times.
- Stationary with the engine idling, fully depress the clutch pedal and wait for 3 seconds, put into back-up (reverse) gear, then 1st gear and then back-up (reverse) gear again. Move the gear selector lever to neutral and release the clutch pedal.
Repeat the whole procedure but wait 20 seconds instead of 3.
Note if there are any differences in sound or moving between the gears in the different waiting times.
Check where the clutch engages and if the clutch sticks or causes noise when depressed. Put into back-up (reverse) gear, accelerate to approximately 2500 rpm. Note any noise or other problems.
- Drive the car on a motor way or similar. Put into 1st gear accelerate and change gear from 1-2 and 2-3 at engine speed (RPM) of approximately 4000 rpm. Then change from 3-4 and 4-5 at as high engine speed (RPM) as possible, although not over 4000 rpm. Engine brake and change down through all the gears at approximately 3000 rpm.
Note any difficulties in putting into gear, if any gears jump out or if there is noise at any gear change.
Repeat the operation above changing gear at approximately 5000 rpm and down changes at 3000 rpm.
- Drive the car in 4th gear at 90-100 km/h with even throttle for approximately 1 minute. Then place in 5th gear, release the clutch momentarily, change out and return to 4th gear.
Repeat 6 times.
Note any problems.