340 door snubber

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  • #83378

    The door support snubber on my plane broke twice in two years.The Cessna replacement part cost $630. I now have an STC replacement from Preferred Airparts, #10015, which is a chrome steel hydraulic cylinder one inch in diameter, much stronger than the Cessna part, for $260. Installation is a simple owner allowed procedure [part 91] with two 3/8 inch wrenches.

    #94413

    Good tip, but I’m a bit confused on which part you’re talking about. Is this the cylinder that slows the descent of the lower half of the cabin door?

    #94414
    quote FBOWLIN:

    Good tip, but I’m a bit confused on which part you’re talking about. Is this the cylinder that slows the descent of the lower half of the cabin door?

    The door snubber slows the extension of the lower cabin door where the steps are. Carwell.

    #94415
    rwelsh
    Participant

      Are you talking about the factory supplied lower door snubber that has a length of cable attached at the upper end. If you are, then it is easy to replace the cable with new cable and necopress fittings. If you are talking about the cylinder with this cable, then the cylinder can be rebuilt by unscrewing the top cap and fitting o’rings in the piston and cap and then filling with 50 weight oil.

      Now if you are talking about the aftermarket snubber that is bolted alongside the factory snubber, that can be replaced with one made by SeaDog of Seattle Fisheries Supply. SeaDog make many sizes of these gas snubbers for minimal money. The exact one that fits the top door is $16.00. The lower aftermarket type is about $30.00 .

      Email me at” dick156@earthlink.net if you have questions.

      #94416
      rwelsh
      Participant

        deleted

        #94418
        quote RWELSH:

        SeaDog make many sizes of these gas snubbers for minimal money. The exact one that fits the top door is $16.00. The lower aftermarket type is about $30.00 .
        .

        Grrrrrrrr…..I am now shocked at what I paid for the upper door cylinder a month ago…. 😥

        I have the lower door cylinder that is chrome and about 1.25″ in diameter. I noticed yesterday a tiny bit of oil where it attaches to the door (not the cabin wall), I suppose it is leaking now. The unit is working fine, but I suspect it will need attention. Is this one serviceable?

        On the door upper, I have a spring(s) that suck the outside handle into the detent that keep going AWOL. So when I close the door, the handle dangles out of the detent. I have had it fixed a couple of times, but the issue reoccurs. Any suggestions?

        I am very careful with my doors. I needed to rebuild the lower door because the steps would not extend by themselves when the door was lowered. There seemed to be something wrong too where the cables attached the the mechanism that kicks the steps out. Took the door apart and there was a bunch of parts that needed to be replaced. The parts took a long time to get, and the time to do the work was long too. I was told not to mess around with door maintenance, they don’t make new ones.

        Jim

        #94422
        rwelsh
        Participant

          Jim, I have never had the upper door apart so I don’t know how the spring is attached although I can see the end of the spring from the outside. I suspect your spring is being installed where the handle mechanism is contacting the spring and eventually breaking the spring.

          When I rebuilt the lower snubber, the top unscrewed with a homemade spanner to fit in two small holes in the top cap. I found some o’rings to fit inside and filled teh top part with 50W oil. It seems to be holding after a few hundred hours and many door openings. If I remember correctly, Cessna changed the lower door snubber about midway through the 12 year building cycle. Most of the parts for teh doors are hidden so they get neglected until something breaks. The hinged for the steps break after so much use and 250 pound passengers jumping on them. The hinges are an easy fix with standard hinge material from Aircraft Spruce; using stainless steel hinges make a stronger hinge then aluminum hinges.

          #94428

          Thanks for the tips.

          I have seen both doors apart. The lower door has some fancy engineering to pop out the steps when the cables pull tight. The cable that sets the steps in motion is where my problems started, when the door was taken apart, there was a bunch of messed up parts. But, it is good now and it is important to keep the cables adjusted so when the door lowers; both cables go taught at the same time. Mine were not (one may have stretched) and that is what created the start of problems.

          I have the manual so I plan to look at the upper door handle. Considering mine has been fixed more than 2 times, I suspect it is more than replacing the spring. Works fine but looks sloppy and more than once someone comes running after me or calls the tower to say my door is open.

          Jim

          Update: There is a spring on the outside handle, looks common to all models, however the manual points to 3 types depending on SN. I have it installed and problem cured.

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