VG-21 Maintenance Item # 16 9 May, 1995
LANDING GEAR TORQUE LINKS:
DESIGN: The torque links are made from 2024-T3 or T4 Aluminum alloy. At Varga we had them machined from 3/4” X 4” rectangular bar. They were cut to shape with a ‘tracer” mill from a master part and then drilled in a fixture for bushings, grease fittings and drain holes. After they were hard anodized, the grease fittings were installed and the bushings pressed in place and reamed to size. Figure 1 should help if you need to make a new torque link. Although not shown on the drawing, look at your old part to see the location of .125” drain holes. They are advisable to preclude corrosion from standing water.
PINS: The pins are made from normalized 4130 steel tubing, heat treated to 145 KSI and then centerless ground to .3125 diameter. Some owners have used an AN175 bolt as a replacement for the pin.
BUSHINGS: Their are two different bushings used in each torque link. They are the same except the two at the landing gear end have holes through one side to let the grease pass through. The other bushings (2) at the linking end have no holes in the side. They are pressed in flush from each side and are short enough to leave a gap between them for the grease to pass through. The bushings are made with an undersized inside diameter and are to be reamed to size after installation.
GREASE FITTINGS: A Stewart Warner #3019 grease fitting is not threaded in place like most grease fittings. Instead, it has a barbed press-in fitting and is installed by forcing it into an undersized hole (.123 diameter).
BOLT: An AN175-22 bolt and an AN31O-5 castle nut with an AN381-2-8 cotter key are used to attach the upper and lower torque links. AN960-516 and AN960-516L washers are used as spacers for bolt length and alignment.
LUBRICATION: General purpose wheel bearing grease works just fine.
MAIN WHEEL ALIGNMENT: The main landing gear is aligned by installing the AN960-516(.060) and/or
-516L (.032) washers between the upper and lower torque links.
LANDING GEAR UPPER STRUT TORQUE LINK BOSS: See the Varga Maintenance Manual and Maintenance Item #17 for repair of this part.
MAINTENANCE AND REPAIR: If greased frequently, normal wear is reduced so that other repairs can be kept to a minimum. Unfortunately, proper greasing may require that the torque links be disconnected at the bolt end so the grease fittings at the gear end won’t be broken off accidentally.
Replacement of worn bolts: Bolts are easy to replace, but you should use a little caution. Make sure
that the wheel will not rotate around the strut when you remove the bolt. If the wheel rotates, the brake line may get pulled or twisted and be damaged. Also, be sure to note the number and type of
washers (thin and thick) installed between the upper and lower links and put them back in the same
position so that the wheels will continue to be aligned when the new bolt is installed.
After taking the above precautions, just remove the cotter pin from the castle nut, take the nut off and slide the bolt out.
Replacement of worn pins: Using the same precautions as when removing a bolt, take out the cotter pins and washers and tap out pin with a 1/4” brass or aluminum drift pin (round bar).
Replacement of worn bushings: Bushing dimensions are shown in figure 1. The easiest way to replace
bushings is to press them out with a new bushing. Otherwise, use a drift pin that is slightly smaller than .375” and tap it out. The tool shown in the maintenance manual will work well.
Replacement of broken grease fittings: If the grease fittings are broken off, they should be replaced at the next grease interval. They usually break off flush with the surface of the torque link which makes it hard to remove them. The easiest way I’ve found to remove them is to push or drive the broken part of the grease fitting through the grease hole into bushing hole. You will need to press out the bushing before you do this because the grease hole in the bushing will be too small for the fitting stub to pass through. If you need to replace the bushing anyway, drill the grease hole in the new bushing oversize (.156 or #21 will do) align the new bushing so that the grease hole is in the right position and press out the old bushing with the new one. You can then drive the grease fitting stub through the grease hole in the new bushing and press in a new grease fitting.