Quote:
|
Originally Posted by b40jpsa
1.I feel my klze has tbta noise. So i want to know if i won't change it's danger to my engine?
2. what is friction gear? how many friction gear in my engine? what is the function of friction gear? i want to see picture too. thx pls
|
The friction gear is designed to quiet the camshaft drive gears which are shallow-angle helicals. There are two, one per bank, and they reside on the gear-side of the intake (front bank) and exhaust (rear bank) cams. In the KL, the timing belt drives the exhaust cam (front bank) and intake cam (rear bank) only. The helical gears in turn rotate the other cams. The friction gear is fastened to the front of the cam and resides against the "driven" gear with a large nut and a belleville-style washer providing a fairly high level of force between the two gears. Thr friction gear has one less tooth than the driven gear but meshes with the drive gear. The result is that the friction gear turns at a slightly different rate than the driven gear. The force of the belleville spring ("friction gear spring") causes a calculated binding to occur as the two gears wipe across each other. The result is that the cam gears are constantly loaded up and noise caused by backlash and cam lobe loading is reduced.
The friction gear relies on that friction gear spring to provide the friction necessary to quiet the cam gears. If the spring relaxes, there will be little friction, no preloading of the cam gears and the things will be as noisy as hell. The friction gear itself is rarely the problem...it's usually the spring that weakens.
You can see the friction gear if you remove the oil filler cap and peer back at the intake cam on the front bank. The gear on that cam will appear to be "split"...the portion toward the belt-side of the engine is the friction gear.
The timing belt tensioner can produce a noise that sounds an awful lot like friction gear noise. While friction gear noise won't hurt anything a broken timing belt tensioner car leave you stranded.
