Q. What is your terms of packing?
A: Generally, we pack our goods in neutral white boxes and brown
cartons. If you have legally registered patent, we can pack the
goods in your branded boxes after getting your authorization
letters.
Q. What is your terms of delivery?
A: EXW, FOB, CFR, CIF, DDU.
What Is a Universal Joint?
A universal joint (also called a universal coupling or U-joint) is
a joint or coupling connecting rigid shafts whose axes are inclined
to each other. It is commonly used in shafts that transmit rotary
motion. It consists of a pair of hinges located close together,
oriented at 90° to each other, connected by a cross shaft. The
universal joint is not a constant-velocity joint.Universal joints
are X-shaped parts typically made of steel with a bearing cap at
each end that allows the vehicle's rigid driveshaft to connect to
the transmission and rotate freely.
They are part of the system that enables the rotating crankshaft in
a vehicle's engine to transfer that rotating motion to the rear
wheels in a rear-wheel-drive vehicle. Because they provide a
flexible connection at the driveshaft's ends, they allow the
driveshaft to move up and down and at an angle to the engine as the
vehicle encounters uneven road surfaces.
For example, pickup trucks have universal joints at both ends of
their driveshafts. Typically, the u-joints connect to yokes that
allow for a driveshaft's fore-and-aft movement and the up-and-down
movement for which the universal joints compensate. Without
universal joints or some similar system, it would be impossible for
a vehicle to have a suspension that offers any substantive wheel
travel. The driveline would bind with every bump and
pothole.Front-wheel-drive vehicles have constant velocity joints,
or CV joints. They perform a similar function to universal joints.
What Does a Universal Joint Do?
Because vehicles don't travel on surfaces as flat as a billiard
table, driveshafts must be able to move up and down with the
suspension while continuing to rotate to ensure uninterrupted power
flow to the drive wheels. The universal joints enable this movement
while allowing the driveshaft to continue to turn.
The use of U-joints makes up for the height misalignment between
the transmission and the rear axle that drives the rear wheels.
Since a vehicle's rear axle and rear wheels move independently of
the rest of the vehicle, a direct driveshaft from the engine to the
axle would bind or flex as the vehicle encounters bumps. The
u-joints compensate for that motion, keeping the driveshaft
spinning freely. As the driveshaft rotates, the flexible
"universal" action of the u-joints automatically compensates for
misalignment.
What Maintenance Is Necessary?
It's obvious that the vehicle's universal joints get a serious
workout any time the car is moving. The faster the vehicle goes and
the more its rear axle travels up and down, the greater that
workout becomes. This suggests that u-joints require maintenance.
The bearings of each u-joint are greased at the factory during
assembly. Some are "lubed for life," and they cannot be serviced
with additional lubrication. Other universal joints have grease
fittings that allow the addition of grease at service intervals.
In either type, the lubrication can diminish over time, and the
"dry" bearing results in wear-causing metal-to-metal contact. You
can lubricate universal joints with a grease fitting, but u-joints
without that ability will simply wear out and need replacement.
Happily, their service life is quite lengthy.
What Are Symptoms of U-Joint Failure?
It is advisable to pay attention to any signs your vehicle's
universal joints are failing because, in the worst- scenario, the
driveshaft could separate from the vehicle, damage it severely and
perhaps cause an accident. Even before total failure, worn u-joints
can lead to costly transmission issues and could leave you stranded
by the side of the road.
Here are some early warning signs of u-joint failure:
Squeaking noise when moving from a standstill
Clunk sound when shifting
Vehicle vibration when underway
Fluid leaks from the back of the transmission
Banging sound accompanied by complete loss of power
To gauge if one or more of your vehicle's u-joints is nearing
failure, you can perform a simple test. With your foot on the
brake, shift the car into reverse and then, after a moment, shift
into drive. If you hear and feel a clunk, a worn u-joint is the
probable cause. The clunk occurs because a failing u-joint allows
too much play at its connection, causing a momentary stall and then
rapid engagement that registers as a clunk.
What Should You Do?
If you think your vehicle's u-joints are nearing the end of their
useful life, have them replaced as soon as possible. The repair is
not very costly and is far less expensive than the repairs required
if you ignore them and suffer transmission problems or a driveshaft
separation.
