Seal and Repair Kits for Cessna Shimmy Dampeners
FAQs for "Seal and Repair Kits for Cessna Shimmy Dampeners"
Frequently Asked Questions
What does temperature compensated mean?
When hydraulic oil changes temperature, the volume of the oil also changes. This volume change from a temperature reduction will create a vacuum in the oil chamber of the original Cessna uncompensated shimmy dampener. This vacuum will cause the oil to vaporize giving the oil a foamy expanded mixture that is compressible. The shimmy dampener action is then drastically degraded. An increase in temperature will increase the oil volume causing a drastic pressurization of the dampener oil chamber. This pressure will force small quantities of oil past the dampener shaft seals. The decrease in oil will then aggravate any temperature reduction with increased chamber vacuum and related oil vaporization. This process explains why continuous servicing of the original shimmy dampener is required.
The temperature compensation system works by having a small chamber of oil that is spring pressurized through a very small passage into the main dampening restrictive orifice of the shimmy dampener. The spring loaded oil chamber can adjust for oil volume changes as temperature changes. A similar system is built into your car shock absorbers. The temperature compensated hydraulic system requires very little service over extended periods of time and assures stable shimmy dampening action.
Why is a hydraulic shimmy dampener better than a rubber dampener?
A rubber based dampener is continuously fatiguing the rubber components as it changes direction of motion. The rubber system depends on stable friction of the rubber riding in a metal tube. This is very difficult to achieve over extended usage. There are inherent differences in static friction of rubber and dynamic friction of rubber that affect dampening performance. Long term use changes the performance of the dampener caused by all of these un-repairable factors. The hydraulic system works in a film oil with stable performance for long periods of time and it is totally repairable.
I installed a torque link kit and serviced my shimmy dampener; why do I still have a shimmy problem?
There are many components all connected to keep the nose gear in line. If one component is worn or out of tolerance it can cause shimmy problem. Reference Dave McFarlane’s article: Can You Stop Nose Gear Shimmy instructions and suggestions.
Overlooked items also include the rod ends, shimmy dampener mounting and attachment, shimmy dampener, and steering collar. The steering collar is where the steering rod tubes connect and the upper torque link is attached to, along with the shimmy dampener on most aircraft. If the steering collar has play vertically and laterally and is allowed to tilt; that will cause excessive wear and force on the torque links, steering, and strut components. There are three different thicknesses of shims to help get the collar in place.
Ensure that the shimmy dampener is working properly with no dead spots in dampening action. The cylinder could be worn on the inside or on a piston that warrants replacement of components. All of the nose strut components are tied to each other and any movement is transmitted through to the tire and back through the dampening system, which if remedied will continue to be more pronounced.
Save $$$ - Repair your fluid dampener with our convenient kits!
Don't buy a disposable rubber dampener. Save money with replacement PMA parts. McFarlane now has affordable repair parts for the original fluid dampener. Save over $400!
- More cost effective than a throwaway unit
- Proven design
- Seal kits include all necessary o-rings and backup rings
- Repair kits include piston assembly, snap rings and housing o-ring
- Hardware kit includes all nuts, bolts, washers, cotter keys and bushings to attach the shimmy dampener to the nose strut.
- Kit components also sold separately
McFarlane's new Shimmy Dampener Assembly also available!
FAA-PMA approved improved temperature compensated shimmy dampeners
Longer life, repairable and better action for a lot less money!
For ordering details, browse our family of shimmy dampeners.
For dampener replacement parts, go to Shimmy Dampener Components.
Why choose McFarlane?
OUR PARTS ARE ENGINEERED TO LAST LONGER WHILE SOLVING KNOWN SAFETY ISSUES
OVER 40,000 PARTS IN STOCK WITH SAME DAY SHIPPING IF ORDERED BY 3PM
OUR TEAM PROVIDES THE OLD-FASHIONED CUSTOMER SERVICE THAT YOU EXPECT
Select a Category
McFarlane Aviation Family
