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spring landing gear
Posted: Wed Dec 11, 2002 4:05 am
by Koop
I have a 1955 cessna 170 B N4468B, serial number 26812. I am trying to find out what spring landing gear I have. I believe it has 180 gear but ca not find stock number on the spring. Have measured the gear of 180 in the hanger next door and it is has the same dimensions. The 180 is being restored so the spring gear on it are stripped of paint, but still no number.
I have no records in the log book of this change.
Posted: Wed Dec 11, 2002 4:34 am
by 54bush170
The 55 models came stock with stiffer gear legs than earlier models so it is probably the same as 180 gear.
Posted: Wed Dec 11, 2002 4:58 pm
by funseventy
The 180 gearleg is approximately 2" longer than 170 gear. The part number on the gear leg will be hard to see if the airplane is assembled, it is on the very bottom of the gearleg on that curved surface.
Good Luck, Kelly
Posted: Wed Dec 11, 2002 5:18 pm
by GAHorn
54bush170 wrote:The 55 models came stock with stiffer gear legs than earlier models so it is probably the same as 180 gear.
None of the original 170 gear legs are the same as
any 180 gear.
gear legs
Posted: Thu Dec 12, 2002 3:50 am
by Koop
Went out to the coast today in Southwestern Oregon, Bandon S05 to visit my new friend N4468B 1955 170B that I should have done a proper pre-buy on. But that is another story. Went to search for part numbers on the gear legs. On the very bottom of the leg were it attaches to the axle I found these numbers stamped into the legs: right leg--9Y27 left leg--9Y22. Not even close to any leg part numbers I could find for the 170 or the 180. Can someone solve this mystery? Koop--N4468B
gear legs
Posted: Wed Dec 18, 2002 6:16 am
by russ murri
Iam sorry but you will not find any numbers that will help you. I just put 180 legs on my 170 ,called cessna tec rep, also xp mods. the early 180 legs mesaure 11/16'' thick add a little for paint. If you have the service related articles from the 170 asss. check on page 5-14 for more help. x p mods told me that he has the drawings for the legs , he gave me some measurements but you have to remove the legs to do it . My 170 is a ragwing we did a new weight a balance, with the new gear it moved the axles 3 3/4'' forward, might check that on yours. the numbers you will find are mostly casting#. the 170 legs are 5/8'' thick Russ
Posted: Wed Dec 18, 2002 5:49 pm
by zero.one.victor
I have the 180 legs on my ragwing,p/n 0741001-5 & 0741001-6 according to the paperwork. The 337 notes "compute new empty weight & balance. Main gear arm from +22" old gear to 18.25" new".
Guess that means the gear is swept forward more. The arm is based on the weight of the gear,not the axle location,so can't say what that might have changed.
If you take some measurements on your airplane from the main gear bottom aft axle bolt back to,say, a particular rivet at the aft end of the plane,maybe me and Russ could measure our airplanes for comparison.I would say measure to the tailwheel attach bolt,but if the tailsprings are different (a la L-19?) that would throw the measurement off. Maybe someone else with late-model stock gear legs could do the same?
Eric
arms
Posted: Thu Dec 19, 2002 3:09 am
by russ murri
Eric the arm is the measurment from the datum(firewall) to a point, the main axle, or tail wheel axle. So in a leveled condition like you do for a weight and balance, if your main axle was +22'' and now is +18.25'' you have moved your axle 3 3/4'' forward. Mine was the same amount , my part numbers are P/N 0740110-3 & -4 off of a 1956 180. Probably the very best thing you can do to a 170. what is the thickness of your gear legs? Russ
spring landing gear
Posted: Thu Dec 19, 2002 3:10 am
by Koop
Thanks for the information. We'll get it figured out. I need the 337 paper work to make my aircraft legal, I believe. I'm pretty sure I have 180 gear, but no paper work. Koop N4468B
spring landing gear
Posted: Thu Dec 19, 2002 3:11 am
by Koop
Thanks for the information. We'll get it figured out. I need the 337 paper work to make my aircraft legal, I believe. I'm pretty sure I have 180 gear, but no paper work. Koop N4468B
Posted: Thu Dec 19, 2002 7:18 am
by zero.one.victor
Russ,I don't recall the thickness of the gear legs,though I recall having measured them. I took a bunch of measurement off my airplane--width of gear legs at axles at empty weight,plus several fore & aft measurements-- for a guy in Montreal named Eric Leclerc,he is in the process of trying to get an STC with Transport Canada for the gear leg swap. I don't know if it would be applicable with the FAA or not.Hope so,then it would just be a STC/337 instead of the field approval BS. I did this back in August,I haven't got a progress report from him. I think he's a member on this site,maybe he'll read this & fill us in.
Eric
Posted: Thu Dec 19, 2002 12:06 pm
by n4517c
According to the Cessna drawing the bend line where the gear comes out of the gearbox is at a different angle for the dash 3,4,5,6 than the dash 1,2. This angle is the one that would move the bottom of the gear forward. The difference is 4 degrees 43 minutes. Also, the angle of the bend near the axle was changed for the dash 3,4,5,6. It was 90 degrees for the dash 1,2 and 85 degrees 17 minutes for the 3,4,5,6. Cessna print says =/- 1 degree