Steer Parts
Hydraulic steering unit Tech – Hydraulic steering unit 101
Hydraulic steering unit can make or break a trail machine. An inadequate system can over-exercise arm muscles while making tight maneuvers very frustrating. Or, if well designed, a hydraulic steering unit system can actually contribute to the overall enjoyment of a day in the dirt. That’s because the amount of physical effort it takes the driver to turn the steering unit wheel relates directly to how well the hydraulic system functions.
A poorly designed system or even a simple misuse of parts for a particular application can result in sluggish, hard-to-use steering unit – not to mention the ill effect on reliability. That’s why we decided to delve into the subject of hydraulics and address a few common issues, while at the same time contrasting the two popular types of setups we see on the trail. We’re going to break this somewhat complex topic into two categories.
Traditionally, this has always been the point where most ‘wheelers cross the line between a trail-only rig and a daily driver. This is because most people feel hydraulic systems are unreliable and therefore not suitable for the street. However, this is not necessarily true. Take a look at the heavy equipment industry: Caterpillar tractors, for example, rely on a variety of hydraulic systems to function, many of which control directional movement.
Hydraulic steering unit systems have their place in several street-driving scenarios, too, though most are found on industrial or agricultural equipment operated at low speeds. These systems are engineered to perform a specific task within a specific range of parameters (i.e., speed, weight, temperature, and environment). The problem here – and probably part of the reason why fully hydraulic steering unit gets a bad rap on the street – is due to system design, or lack thereof. It all boils down to economics.
No common man is willing to invest the millions it took Caterpillar to develop a fully hydraulic steering unit system reliable enough to pilot its dump trucks down the road safely. And because there are several sources for hydraulic steering unit components, all with very little “specific information” about each particular application, it’s hard for Joe Consumer to know which widget to install on his own rig. Full hydraulic steering unit requires eight major components: Each is equally important to the overall performance of the system. That’s why it’s most important to build a balanced or matched system.
For most ‘wheelers, the somewhat less expensive, less complex hydraulic assist may be the best option. In most cases, companies offer complete kits for specific vehicle applications like the PSC kit shown above for the ’05 Jeep TJ. With an assist setup, your rig’s mechanical steering unit remains intact, enabling the option of manual steering unit if the hydraulics should fail.
We like this setup for trail rigs that are driven on pavement from time to time. Aside from helping your steering unit system push around larger meats, a ram assist can function as the ultimate steering unit dampener, too. At the same time, a ram assist also helps relieve stress on other steering unit components such as the steering unit box. The major difference between hydro-assist and fully hydraulic steering unit is that hydro-assist is basically a piggyback setup you add on to your existing steering unit system, while a fully hydraulic system is a stand-alone system relying completely on fluid power.
This is the hydraulic fluid (or power-steering unit fluid) reservoir that stores the fluid necessary for the system. Think of it as an oil pan. Most power-steering unit pumps have a reservoir attached right to the pump body. The one shown here is a PSC part. At a minimum, the reservoir must be large enough to hold reserve oil for both extended and collapsed cylinder lengths. To figure out what you need, consider the oil volume-to-duty cycle ratio.
In heavy equipment, this ratio is roughly 3:1, meaning your reservoir should hold three times the volume of the system. This is probably overkill for our purposes because this ratio was designed for 100 percent duty-cycle applications such as a bucket loader working at a strip mine that runs 24/7 all year long. A Jeep or buggy will typically see use on the weekends for recreational purposes only, so you really wouldn’t need a 3-gallon power-steering unit reservoir. Keep in mind how often you use your rig and how much time the system will actually run once installed. In most cases, the supplier will have two or three different sizes of reservoirs to choose from.
Similar in function to the automotive “steering unit box,” this part translates driver input at the steering unit wheel to actual movement of the cylinder. Many people call them “orbital valves.” This is incorrect. “Orbital” refers to a specific type of hydraulic motor that has nothing to do with hydraulic steering unit. The hydraulic industry refers to these as steering unit control units (SCU) or, more commonly, metering valves. Metering valves have a specific displacement volume, which equates into how many cubic inches of fluid can pass through the valve in one 360-degree revolution. The rule on metering valves is: The higher-volume (in cubic inches) valve you get, the faster the wheels will cycle through the range of movement.
Someone started a rumor about fully hydraulic steering unit being illegal for use on the highway. This is not true. We contacted the U.S. Department of Transportation and asked about the rules on hydraulic steering unit systems. We were told that any rules prohibiting the use of fully hydraulic steering unit systems in the automotive aftermarket would fall under local laws. We suggest you check with your state’s local transportation authorities if you question the legality of hydraulics.
About the Author
Zhongyi Hydraulic Motor Company is a professional engaged in radial piston motor,axial piston motor,slewing transmission,danfoss motor,hydraulic orbital motor,hydraulic steering unit. All products are strictly tested before delivery by testing bench and comprehensive testing facilities to ensure the quality.
|
|
FRONT STEER CHASSIS FRAME ROLL CAGE NASCAR 04 PARTS 1/24 Model Car Mountain KIT $3.99 |
|
|
Forklift Rod End No. 06-1300219, Fork Lift Truck Part hyster steer tie rod end? $4.00 |
|
|
game part Rodeo-opoly property trading cards monopoly replacement $4.24 |
|
|
game part Rodeo-opoly property trading cards monopoly replacement $4.24 |
|
|
John Deere 60 Skid Steer Loader Parts Catalog PC-1615 $4.99 |
|
|
Murray Upper Steer Plate part # 021489E700 *New* B3 $4.99 |
|
|
John Deere 165 Backhoe for 170 Skid Steer Loader Parts Catalog Manual 74 $4.99 |
|
|
1/25 REAR STEER LATE MODEL RACING MODEL KIT PARTS $4.99 |
|
|
1/25 REAR STEER LATE MODEL CHASSIS NASCAR RACING MODEL KIT PARTS $4.99 |
|
|
1/25 FRONT STEER LATE MODEL RACING Model Car Mountain KIT PARTS $4.99 |
|
|
New Holland Parts Catalog – L-250 Skid-Steer Loader $5.00 |
|
|
John Deere 165 Backhoe for 170 Skid Steer Loader Parts Catalog Manual 76 $5.99 |
|
|
BOLENS REAR STEER 8HP RIDER MODEL 943 PARTS MANUAL $6.00 |
|
|
BOLENS FRAME STEER 11 HP, 12 HP TRACTOR PART LIST MODEL 943 , 944 $6.99 |
|
|
JOHN DEERE 165 BACKHOE SKID STEER PARTS MANUAL $7.44 |
|
|
JOHN DEERE 165 BACKHOE PARTS CATALOG SKID STEER 170 $7.99 |
|
|
JOHN DEERE 165 BACKHOE FOR SKID STEER PARTS MANUAL $9.79 |
|
|
BOBCAT 843 SKID STEER LOADER PARTS CATALOG $9.95 |
|
|
BOBCAT 843B SKID STEER LOADER PARTS CATALOG $9.95 |
|
|
BOBCAT 743 SKID STEER LOADER MASTER PARTS CATALOG $9.95 |
|
|
Bolens 933 Villa Rear Steer 8 HP Rider Tractor Parts Manual $10.00 |
|
|
Sno Stuff E-Z Steer Wear Bar Part # from Dennis Kirk 03-1617 (s) $10.00 |
|
|
XTM 149455 Servo Saver Metal Parts 1/8 Bellcrank Steer $10.89 |
|
|
a1157) New Holland Parts Bk L250 Skid Steer Reprints $11.99 |
|
|
JOHN DEERE 200 SYNCHRONOUS PARTS CATALOG SKID STEER 170 $12.25 |
|
|
New Holland Deutz F3L912 Diesel Engine for L775 Skid Steer Dealer’s Parts Book $12.99 |
|
|
Steering Coupler 3/4 – 36 spline IMCA Modified Steer $12.99 |
|
|
New Holland L250 L-250 Skid Steer Loader Parts Catalog $12.99 |
|
|
RPM81052 In-Line Steer Blocks Blitz RPM PRODUCTS CAR/TRUCK PARTS $13.95 |
|
|
NEW HOLLAND L-325 SKID STEER LOADER PARTS CATALOG $14.75 |
|
|
John Deere 125 SKID-STEER LOADER Parts Catalog; Horicon Works manual PC-1588 $14.90 |
|
|
John Deere 165 Backhoe for 170 Skid Steer Loader Parts Catalog PC1374 jd $14.95 |
|
|
Gehl 3510 3610 Skid Steer Dealer’s Parts Book $14.99 |
|
|
Gehl SL3635 SL3935 Skid Steer Dealer’s Parts Book $14.99 |
|
|
Gehl 6620 Skid Steer Dealer’s Parts Book $14.99 |
|
|
New Holland L-225 Skid Steer Loader parts catalog $14.99 |
|
|
John Deere Action Part 1 DVD NEW. Cotton picker, skid steer, tractors, trucks. $14.99 |
|
|
John Deere 60 Skid Steer Loader Parts Catalog Manual 78 $14.99 |
|
|
John Deere 60 Skid Steer Loader Operators Manual Service Repair Parts JD $14.99 |
|
|
18HP NOMA ALL WHEEL STEER BELT & MISC PARTS $14.99 |
|
|
NOMA ALL WHEEL STEER MISC PARTS $14.99 |
|
|
Trojan Front Loader Parts! 2083521 Steer Cyl End Clips $14.99 |
|
|
Case 1816B Uni-Loader Skid Steer Loader Parts Manual Suplement for 1816 Catalog $15.00 |
|
|
NEW HOLLAND L-35 SKID STEER LOADER SERVICE PARTS CATALOG $15.00 |
|
|
NEW HOLLAND L-225 SKID STEER LOADER SERVICE PARTS CATALOG $15.00 |
|
|
Bolens 940 (FS11) Frame Steer 11 HP Tractor Parts Manual $15.00 |
|
|
Bolens 942 Frame Steer 11 HP Tractor SN P3557-3 Parts Manual $15.00 |
|
|
Bolens 942 Frame Steer 11 HP Tractor Form P3841 Parts Manual $15.00 |
|
|
Bolens 943 944 Frame Steer 11 12 HP Tractor Form 176-0244 Parts Manual $15.00 |
|
|
Case 1845 & 1845S Uni Loader Skid Steer Revision #1 Parts Manual #D1277-R1 $15.00 |
|
|
New Holland L-779 Skid Steer Loader Parts Catalog book $15.95 |
|
|
Ford New Holland L-544 Skid-Steer Loader Dealer’s Parts Manual $15.99 |
|
|
New Holland L-451 & L-452 Skid-Steer Loader Dealer’s Parts Manual $15.99 |
|
|
BOLENS FRAME STEER 11 HP TRACTOR PARTS LIST MANUAL MODEL 940 (FS 11) $17.00 |
|
|
Gehl 4615 Skid Steer Service Parts Manual (Used) $17.50 |
|
|
Ford L-784 Skid-Steer Loader Service Parts Catalog $17.99 |
|
|
New Holland L-325 Skid Steer Loader Parts Catalog $17.99 |
|
|
John Deere 24 Skid Steer Loader Dealer’s Parts Book $17.99 |
|
|
CAT Take-A-Part Vehicle – Skid Steer $17.99 |
|
|
Hydra Mac 2250 Skid Steer Loader Parts Manual $18.50 |
|
|
Hydra Mac 1300K 1300 K Skid Steer Loader Parts Manual $18.95 |
|
|
John Deere 75 Series Skid Steer Parts Catalog $18.99 |
|
|
Vintage New Holland L779 Skid Steer Loader parts catalog $18.99 |
|
|
Gehl SL3515 SL3615 Skid Steer Loader Parts Catalog manual book OEM printed 1991 $18.99 |
|
|
Gehl SL4510 SL4610 4510 4610 Skid Steer Loader Parts Catalog manual no.903196 $18.99 |
|
|
NEW HOLLAND L-225 SKID STEER LOADER PARTS MANUAL BOOK $18.99 |
|
|
NEW HOLLAND L-250 SKID STEER LOADER PARTS MANUAL BOOK $18.99 |
|
|
NEW HOLLAND L-325 SKID STEER LOADER PARTS MANUAL BOOK $18.99 |
|
|
NEW HOLLAND L-445 SKID STEER LOADER PARTS MANUAL BOOK $18.99 |
|
|
NEW HOLLAND L-779 SKID STEER LOADER PARTS MANUAL BOOK $18.99 |
|
|
New Holland L779 Skid Steer Loader Parts Catalog Manual $19.75 |
|
|
Gehl 3510 3610 Skid Steer Loader Parts Catalog Manual $19.95 |
|
|
JOHN DEERE 165 BACKHOE SKID STEER PARTS MANUAL $19.95 |
|
|
JOHN DEERE 165 BACKHOE SKID STEER PARTS MANUAL $19.95 |
|
|
John Deere JD 90 Skid-Steer Loader Parts Catalog PC1682 $19.99 |
|
|
NEW HOLLAND L-425 SKID STEER LOADER PARTS CATALOG $19.99 |
|
|
NEW HOLLAND L-778 SKID STEER LOADER PARTS CATALOG $19.99 |
|
|
1978 NEW HOLLAND L775 SKID STEER LOADER ENGINE PARTS CATALOG $19.99 |
|
|
1979 JOHN DEERE PARTS MANUAL FOR 60 SKID-STEER LOADER $19.99 |
|
|
Gehl SL3635 SL3935 Skid Steer Loader Parts Manual $19.99 |
|
|
New Holland L465 LX465 LX485 Skid-Steer Loader Dealer’s Parts Manual $19.99 |
|
|
NEW HOLLAND L-779 L779 SKID STEER LOADER PARTS MANUAL $19.99 |
|
|
John Deere 70 Skid Steer Loader Parts Catalog Manual 78 $19.99 |
|
|
John Deere 170 Skid Steer Loader Parts Catalog Manual 78 $19.99 |
|
|
GEHL 6620 SKID STEER LOADER PARTS BOOK MANUAL $19.99 |
|
|
John Deere 60 Skid Steer Looader dealer’s parts book $19.99 |
|
|
2004 Gehl SL 3635 3935 Skid Steer Loader Parts Manual C $19.99 |
|
|
GEHL PARTS MANUAL SERIES HL 4400 SKID STEER LOADER $19.99 |
|
|
New Holland Model L-250 L-255 Skid Steer Loader Dealer’s Parts Book $19.99 |
|
|
New Holland Model L-325 Skid Steer Loader Dealer’s Parts Book $19.99 |
|
|
New Holland Model L-425 Skid Steer Loader Dealer’s Parts Book $19.99 |
|
|
New Holland Model L-445 Skid Steer Loader Dealer’s Parts Book $19.99 |
|
|
NEW HOLLAND L-250 SKID-STEER LOADER DEALER SERVICE PARTS CATALOG $19.99 |
|
|
New Holland L-445 Skid-Steer Loader Service Parts Catalog Manual 5044514 8/81 $20.00 |
|
|
New Holland L-451 Skid-Steer Loader Parts Manual $20.00 |
|
|
New Holland L-250 Skid-Steer Loader Parts Manual $20.00 |
|
|
Case 1816C Uni Loader Skid Steer Parts Manual Catalog # 8-1350 $20.00 |
|
|
CAT AIR FILTER FOR 252B SKID STEER PART #110-6331 $20.00 |
|
|
Mustang Service Parts Skid Steer Loader Price List. $20.00 |
|
|
New Holland L-779 Skid -Steer Loader Parts Catalog $20.99 |
