Crossover AWD / 4WD Systems

TIMELINE:
0:00 Introduction
0:35 Power Transfer Unit (PTU)
1:40 The Link Shaft (Axle shaft)
2:22 Transaxle differentials and the link shaft connection
4:16 The PTU connection to the differential case
6:00 The internal parts of a PTU
7:40 The spool and the ring gear
8:10 The PTU spool connection to the transaxle differential case
8:48 The transaxle final drive underdrive gear ratio of 4.356:1
10:05 The PTU gear overdrive ratio of 0.439:1
11:58 The rear axle gear ratio of 2.2779:1
13:05 Two different axle gear ratios on the same vehicle
14:36 The rear driveline spins at an RPM related to the rear axle gear ratio, not the front final drive gear ratio.
15:33 The rear driveline does not always have a direct connection to the pinion gear
18:08 On-vehicle view of the PTU
19:58 On-vehicle view of the three-piece driveline
21:12 On-vehicle view of the rear differential with a clutch pack connection
24:15 Summary

ABOUT US:
Weber State University (WSU) - Automotive Technology Department - Transmission Lab. This episode covers the operation of a typical Crossover All Wheel Drive (AWD/4WD) system with a Power Transfer Unit PTU) on a Crossover SUV. A Crossover SUV is a vehicle that is primarily front-wheel drive but can have an all-wheel drive or 4-wheel drive option. We teach current vehicle technologies to our automotive students at Weber State University and online. For more information visit: http://www.weber.edu/automotive

This video was created and edited by Professor John D. Kelly at WSU. For a full biography, see http://www.weber.edu/automotive/J_Kelly.html

Visit my other youtube channel https://www.youtube.com/user/vibratesoftware to see the amazing NVH app for vibration diagnosis!

This video helps satisfy the requirements of the following NATEF Tasks:
3.F.5 – 4WD/AWD - Diagnose noise, vibration, and unusual steering
concerns; determine necessary action - Priority Level 3

Question for Teachers:
1. What is a Crossover SUV?
2. What the meaning of the PTU abbreviation?
3. Is a PTU used on a vehicle with a transversely-mounted engine or a longitudinally-mounted engine?
4. To what part is the PTU housing attached?
5. To what transaxle part is the PTU spool and ring gear attached?
6. What effect does the PTU have on the front differential action of the transaxle?
7. Is the rear driveshaft driven faster or slower than the PTU spool and ring gear?
8. What is the Front transaxle gear ratio of the vehicle in the video?
9. What is the rear axle gear ratio of the vehicle in the video?
10. How can there be two different gear ratios on the same vehicle and still have all the tires spin at the same speed?
11. How is power transferred from the driveline (Propeller shaft) to the rear axle?
12. What is the purpose of the electrical connector at the rear axle?
13. Name two conditions under which power transferred to the rear axle?
14. Tell me one thing you learned from this video

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Видео Crossover AWD / 4WD Systems канала WeberAuto