310S driveline and transmissions practice questions.

Five free practice questions on driveline and transmissions: block D of the Red Seal 310S Automotive Service Technician exam, about 17 of its 125 questions. They are in the exam's format: four options, one correct answer. Answer each one before opening the explanation. No account, no email.

01The questions

1. Critical · Diagnoses clutches

   A clutch chatters and shudders as it is engaged from a stop, but holds without slipping once fully engaged. Under the vehicle, the engine's rear main seal has been weeping. What is the most likely cause of the chatter?

   1. Excessive clutch pedal free play
   2. A worn release bearing
   3. Air in the clutch hydraulic system
   4. Oil contamination of the clutch disc
   Show the answer

   D. Correct. Oil from a leaking rear main or transmission input seal glazes the friction facings and makes them grab and release unevenly as the clutch takes up, producing chatter. Fix the leak, and replace the disc (and usually the pressure plate); a contaminated disc cannot be cleaned. Loose engine or transmission mounts and hot spots on the flywheel are the other common chatter causes.

   Why not the others

   A. Too much free play delays release and can cause drag; it does not cause a shudder as the clutch takes up drive.

   B. A failed release bearing makes noise when the pedal is pressed. It does not affect how the disc grips as it engages.

   C. Air gives a soft, low pedal and incomplete release (drag), not a shudder during engagement. The pedal here is not described as abnormal.

2. Procedural · Repairs automatic transmissions and transaxles

   An automatic transaxle has no dipstick; fluid level is set with a check (level) plug in the case. What is the correct procedure for checking the level after a repair?

   1. Engine running at the specified temperature, fluid just trickles from the plug
   2. Fill only by the capacity listed in the service manual
   3. Engine off and hot, add fluid until it runs freely from the hole
   4. Engine off and cold, remove the plug and add fluid until it is level with the hole
   Show the answer

   A. Correct. Bring the fluid to the manufacturer's temperature window (often about 35–45 °C, checked with a scan tool), engine running so the converter and circuits are full, transmission in Park or as specified, then remove the plug — a thin trickle means the level is right. Too hot or too cold gives a wrong level, which is why the scan tool temperature reading matters.

   Why not the others

   B. Capacity is a starting point; the amount retained in the converter and cooler varies. The level must be verified at the plug at the specified temperature.

   C. With the engine off the converter drains back into the pan and the level reads high. The check must be done with the pump running, in the temperature window.

   D. ATF expands considerably as it warms. Setting the level cold gives an overfill when hot, which causes aeration, foaming and leaks from the vent.

3. Procedural · Diagnoses automatic transmissions and transaxles

   In an automatic transmission, line pressure of 800 kPa (116 psi) acts on a clutch piston with an effective area of 50 cm². Ignoring the return springs, what force applies the clutch pack?

   1. 0.4 kN (400 N)
   2. 4 kN (4000 N)
   3. 8 kN (8000 N)
   4. 40 kN (40 000 N)
   Show the answer

   B. Correct. Pascal's law: force = pressure × area. 800 kPa = 800 000 N/m², and 50 cm² = 0.005 m², so 800 000 × 0.005 = 4000 N, about 4 kN (roughly 900 lb). This is why a modest line pressure can clamp a clutch pack hard, and why piston area is one of the levers a designer uses to set clutch capacity.

   Why not the others

   A. This treats 50 cm² as 0.0005 m². There are 10 000 cm² in a square metre, so 50 cm² is 0.005 m² — ten times larger than assumed.

   C. This counts the piston area twice, as if pressure pushed on both faces. Apply pressure acts on one face only; the other side is vented or opposed by return springs.

   D. This multiplies kPa by cm² directly (800 × 50) without converting units. Both terms must be in consistent SI units before multiplying.

4. Procedural · Repairs clutches

   During a clutch replacement, what should the technician do with the pilot bearing and the transmission input shaft splines?

   1. Replace the pilot bearing; leave the splines dry in every case
   2. Pack the pilot bearing with chassis grease and reuse it
   3. Replace the pilot bearing; apply only a light film of the specified grease to the splines
   4. Reuse the pilot bearing if it turns freely; pack the splines heavily with grease
   Show the answer

   C. Correct. The pilot bearing is inexpensive and buried; replace it every time (using a puller or slide hammer, or the grease-and-drift hydraulic method for a bushing). A very light coat of high-temperature spline grease lets the disc slide freely for release, unless the manufacturer specifies dry splines. Wipe off any excess and keep grease off the facings.

   Why not the others

   A. Most manufacturers call for a light film of a specified grease so the disc does not hang on the splines and drag. Some do specify dry assembly, which is why the service information must be checked rather than assumed.

   B. A worn or sealed pilot bearing cannot be rejuvenated with grease, and chassis grease is not rated for the heat behind the flywheel. Replace it.

   D. A pilot bearing that feels fine on the bench often fails soon after the new clutch goes in, and excess spline grease is flung onto the disc facings, causing slip and chatter.

5. Critical · Diagnoses transfer cases

   An AWD crossover has a whine that rises with vehicle speed and gets louder under acceleration, loudest from the front near the power transfer unit (PTU). The PTU fluid is very low, dark and smells burnt. What is the most likely cause?

   1. Tire noise from uneven tread wear
   2. An internal transaxle fault
   3. A front wheel bearing
   4. PTU gear and bearing wear from fluid loss
   Show the answer

   D. Correct. PTUs hold a small quantity of fluid and run hot; a leaking seal or degraded fluid quickly wears the hypoid gears and bearings, giving a load-sensitive whine. Find the leak (often the PTU input seal, which can also let transaxle fluid in), and expect the unit to need replacement if it has run low. Regular PTU fluid changes are the prevention.

   Why not the others

   A. Tire drone changes with road surface and is unaffected by throttle. A whine that increases with load is gear noise.

   B. A transaxle fault would usually bring shift symptoms and DTCs, and the transaxle fluid is separate from the PTU. The burnt fluid is in the PTU.

   C. A wheel bearing growls with road speed and changes when the vehicle is swerved to load it side to side; it does not respond to engine load or explain burnt PTU fluid.

02Answer key

03What block D covers

This block covers everything between the engine and the wheels: driveshafts, U-joints and CV axles, manual transmissions and synchronizers, automatic transmissions, torque converters, CVTs and dual-clutch units, clutches and flywheels, transfer cases and AWD power transfer units, and differentials, including ring-and-pinion setup, backlash and limited-slip service.

The Red Seal Occupational Standard names this block “Diagnoses and repairs driveline systems”. It carries 13.6% of the exam, about 17 of the 125 questions, split across two tasks. The share column is each task's weight within the block, as the standard publishes it.

04What the questions turn on

Driveline vibration signatures

A vibration that follows road speed and changes with throttle points to U-joint angles or a worn joint. The two working angles on a shaft must be nearly equal so their speed fluctuations cancel; shimming the pinion brings them into line.

Clutch slip versus drag

Engine speed rising without road speed is a slipping clutch, and missing pedal free play is the first thing to check. Grinding into gear only with the engine running, with clean shifts engine-off, means the clutch is not releasing.

One gear or every gear

Slip in only one gear with normal line pressure in every range points to that gear's clutch or band circuit. Line pressure low in every range that will not rise on command points to the pump, filter or regulator valve.

Reading the gear pattern

A drive-side pattern sitting high on the tooth face means the pinion is too shallow, and a thicker pinion shim moves it deeper. Too much backlash means moving the ring gear toward the pinion. Re-check backlash and pattern after each change.

05The other blocks

The 310S exam has eight blocks. Each has its own page of free questions:

The 310S Automotive Service Technician practice exam page describes the full question bank. How these questions are written and checked: how our questions are made. Found a mistake? Tell us and we will fix it.