Tuesday, May 10, 2011

Clutches

 Today we took a look at clutches , we took apart the clutch from a Toyota Corolla 3k engine.

The clutch is a mechanical device which provides for the transmission of power from one component to another.The main bits are the flywheel, clutch disc, pressure plate and the release mechanism. 

It was very simple we first started by removing the clutch operating cable from the pedal and then removed the bolts which hold the bell housing to the engine which gave us access to the clutch.We inspected the pressure plate for damage/wear to the fingers, there were some amounts of wear on the fingers and also on the clutch plate we found out that it was worn, to fix this we would have replaced the clutch plate/pressure plate and release bearing if it was in a workshop situation. We then reassembled the unit , it was very easy we used a input shaft input shaft to line the clutch up and tighted the bolts to the specification and bolted back the bell housing then put the cable back.

Wednesday, May 4, 2011

Differential

Today we opened up a Toyota Corona Diff , RT100
First we removed the end bearing caps which allowed the crown wheel to come out and then unbolted a nut on the flange which holds the drive pinion in the housing. I then used a punch to tap out the shaft which supports the pinion gears, from there i removed the pinion and side gears from their housing.
I then followed my workbook to begin carrying out the inspection, checking the teeth for any cracks,chips,wear , checking the bearings for noise,roughness. The condition of the teeth were good.

Monday, May 2, 2011

Automatic Transmission

 Today we took apart a rwd automatic transmission
We started by placing the gearbox upside down on a stand so the oil pan could be removed, from there we removed the valve body, this directs the ATF to the valves which controls the clutches, gear changes, brake bands. We then took out the oil pump which supplies pressurized oil to the valve body. The input shaft, clutches and planetary gear set was then removed followed by the output shaft and governer valve.
The Planetary gear set
3 main components
  • Sun Gear
  • Planetary Gears and Carrier
  • The Ring Gear


Valve Body , it is the hydraulic control centre that recieves fluid from the main pump opearated by the fluid coupling or tourque converter.


One key component of the automatic transmission is the planetary gearset. Planetary gearsets allow a transmission to contain different gear ratios, with different clutches holding certain components on position. Planetary gearsets are comprised of a sun gear, planet gears and the planet gears, carrier and the ring gear.

Wednesday, April 13, 2011

CV Joints

CV joints allow a drive shaft to transmit power through a variable angle, at constant rotational speed, without an appreciable increase in friction or play. They are mainly used in front wheel drive and all wheel drive cars. Rear wheel drive cars with independent rear suspension typically use CV joints at the ends of the rear axle halfshafts, and increasingly use them on the propshafts.


They are protected by a rubber boot, a CV gaiter. Cracks and splits in the boot will allow the joint to corrode and a new joint would need to be fitted if the joint is not removed early enough, cleaned, greased, and a new boot fitted.

Tuesday, April 5, 2011

Transmissions

A transmission provides speed and torque conversions from a rotating power source to another device using gear ratios