What is a Transmission Gearbox?

A Gearbox is a machine-driven process of shifting energy from one device to another. A transmission gearbox is most frequently positioned at the junction point of a power shaft, and is used to generate a right angle change in direction. It provides a range of gearing to multiply the engine’s torque.  A direct connection from the engine to the road wouldn’t provide enough torque at the wheels to move the car.  Thus, the gearbox’s multiplication of the toque is what helps overcome the car’s inertia and gets it moving.  I hope the gearbox is better at multiplication then I am, or my car is not going anywhere.

There are three main types of gearboxes; Front Engine-Front Wheel Drive, Front Engine-Rear Wheel Drive, and Rear Engine-Rear Wheel Drive.  A FWD drive is condensed and will commonly contain the gears, the final drive, and the differential. There are two shafts, an input shaft and an output shaft. The gears are constantly meshing but just one gear is secured to the shafts at all time.

The RWD gearbox has three shafts.  Just like the FWD it has an input and an output but the RWD also contains a lays half shaft.  The input and output shafts run parallel to each other and the lays half sits below the two and overlaps them.  The input shaft drives the lay shaft through a pair of meshing gears.  This act is continuous and goes by the term, “constant mesh.” This term does not apply to your friend who constantly just wears mesh basketball shorts. The lay shaft and output shaft have a pair of gears rotating on them and from the constant mesh gearing onwards it behaves just like the FWD gearbox. The main difference between a FWD and RWD gearbox is what is known as a direct ratio, which is when a system locks the two shafts together and bypasses the gear cluster.

Transmission gearboxes are either automatic, manual, or continuous.  A manual transmission can be a sliding mesh or a constant mesh style. The sliding mesh uses straight cut gears and requires the driver to time the change from one speed to another.  If it is not timed right there will be a loud grinding sound and increase the rate of wear and tear on the gears teeth, and it will also cause you to yell at your girlfriend.  The constant mesh system has diagonally cut gears that are permanently meshed. This creates a smoother transition between speeds.  The constant mesh is used mostly by agricultural equipment and race cars.

Tight Steering After a Rack Install

Recently the vehicle you drive had a leaking steering rack and it is leaving puddles everywhere you go. You think to your self "great! how much is this gonna cost?" so you find the power rack or power gearbox that you need online for a good price. The install goes well and the mechanic stands behind his work but the car is really hard to turn.  This must mean the part is bad...it is the only new part to the car and the old one turned fine.

After all this time and money the mechanic is telling you that the rack you ordered is bad and he will not warranty the labor cost. So now it is time call and scream at the company who sold the rack. But hold on...is there really issue tor more did the new rack that has exposed a preexisting issue. Many times an old power steering rack is loose and very easy to move, this means very little force is needed from the power steering pump. When the old worn out pump is now coupled with the new rack means that it may not make enough pressure to turn the rack. A tight rack can seem like a binding rack but it will never bind in both directions. An easy way to check for a failing pump is to rev up the motor and see if the car turns easier...if it does, you have a bad pump.

Mechanics don't care about diagnosing the issue most of the time if you bring your own parts but they are happy to charge labor again and again. Be sure that the company who is installing the part knows what they are doing and that they are good people. Every company can smile at you and act like a friend...walk onto a used car lot and you will have a new best friend till you buy a car but its all an act. Make sure the repairs to the steering system are done by a trust worthy company that can determine real issues for you.

How to Center a Power Steering Gearbox

When installing a new power steering gearbox there are a few crucial steps that need to be followed in order to have a successful installation. Before installing a power steering gearbox or manual steering gearbox, it is important that the unit is centered. Many mechanics will assume that the unit is centered when it arrives, however usually it is not. Gearboxes can shift in transit, causing it to be misaligned. In order to center the unit before the install, follow these easy steps.

1) Place the unit somewhere it can be braced down and cannot move or fall.

2) Cover the spline with a cloth to prevent damaging the splines during the centering procedure.

3) Attach a wrench to the input shaft and turn until it stops. (never force the unit) This will be the extreme for this direction. (for this install turn clockwise first)

4) Once the unit is at extreme clockwise rotation, mark the unit or move the wrench to a position where the number of return rotations can be counted easily.
5) With this position marked, begin to rotate the shaft back clockwise and count the number of rotations. Be exact on this! Once the rotation stops clockwise, the complete rotations for the unit are known.

6) Divide the number the number of rotations in half and rotate the shaft that many turns back. At that point, the gearbox will be centered and can be marked for center, so that the center is not lost during the install.

7) Once the box is centered, follow the proper procedure for the gearbox installation.

When these short steps are followed carefully, the gearbox will be centered and there should be no issues with the vehicle’s steering.