$6000
(labor only, parts extra)
This includes removing every part of the landing gear system (except the actuator assembly), disassemble, clean and inspect, replace all bearings (except main gear trunnion bearings), reassemble with new seals and any other needed parts, and of course rigging the gear. Essentially, the entire landing gear system is made new again. This also includes:
- injecting grease (with my custom tool) into the main gear trunnion bearings.
- Disassembling the reduction gear box, removing all of the dried grease and repacking with new grease.
- Magnetic particle inspection of the MLG torque tube fork-head bolts.
- Removing the MLG inner doors and replacing the door hinge bushings (which are always seized in the magnesium hinges.)
- All hardware is replaced with new.
Options for the gear system overhaul:
Strip & paint all parts with automotive paint (not “rattle can”) $4000
As you can imagine, this is a tedious and time-consuming job. All of the parts are media-blasted to bare metal, masked, primed and painted. Are there are a LOT of parts! Hence the price. I use a two-part polyurethane paint (Imron) over an epoxy primer. Expensive….
Replace main strut trunnion bearings: $100/hour
If your trunnion bearings are completely frozen and can’t be saved, they must be replaced. This is a horrible job. They are a press fit into the wing spars, against a blind shoulder. I can get the inner race and rollers out with a puller, but the outer race has to be CAREFULLY cut out with a Dremel and a carbide cutter. I hate this job….
Re-chroming struts: $400/strut
(labor only, does not include chroming, parts or repaint)
Pull strut tube out of lower gear leg and re-assemble after chroming with all new seals.
Let me explain…
A lot of 310’s have pits in the chrome. By itself, this isn’t bad; it won’t make the gear collapse. But it is ugly, and the pits wear out the seals rapidly, resulting in oil leakage and struts that won’t hold pressure. The only way to fix this is to re-chrome the struts. However…
The chrome tube is a very tight press-fit into the lower gear leg. And inside the tube, at the bottom, there is an aluminum plug with two o-rings. These o-rings seal the upper portion of the strut where the oil and pressurized nitrogen live. During the re-chroming process, the high temps and acids destroy those o-rings. So if you get the strut re-chromed without taking it apart, you will have a leaky strut.
Note: if you have a mysterious oil leak from the very bottom of the gear leg, and the leak is not coming from the seal or the very top of the strut, then this o-ring is leaking. Hey, they don’t last forever…
Ok, back to our plug and o-ring… so we must get that out before the tube gets re-chromed. And the only way to get the plug out is to pull the tube out of the lower leg, then push the plug out of the bottom of the tube. Here is where it gets interesting… as far as I know, I’m the only guy that has figured out how to do this. I had to make special tooling and the entire disassembly process is not easy. So no… you can’t do this at home and it isn’t something that you can fly in and have me do in one day.
I have the actual chrome work done at an FAA Repair Station in Los Angeles. I don’t charge extra for transporting the struts to and from the chrome shop, but the shop’s going rate is around $550 per strut. (as of 2023) And of course, once I get the newly-chromed struts back, I have to press them back together.
Note: the process of pulling the strut tube out and reinstalling it involves using a propane flame for heat. This will destroy whatever paint is on the lower leg, so they will need to be repainted.