Installed 180 Landing Gear

How to keep the Cessna 170 flying and airworthy.

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n2582d
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Re: Installed 180 Landing Gear

Post by n2582d »

canav8 wrote:The gear will move aft through use not forward. ... If the gear moves due to difficult landings like heavy crosswind landings and braking, the gear will eventually move aft. ...
I have thought the same thing so I was surprised to see wear marks at the forward end of my outboard landing gear extrusions. Maybe the castor angle drives the leg forward if the wedges are loose? Have others seen this?
Gary
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GAHorn
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Re: Installed 180 Landing Gear

Post by GAHorn »

Doug, unless my brain is reversed again... placing a washer beneath the upper gearleg raises that wing instead of lowering it. (It fulcrums the gearleg (lever) downward at the axle-end.)

Del's explanation is a symantic - mirage much like my own description above.... It reminds me of the groundschool instructor who warned the clients about checking the gear-handle of the Hawker jet before starting an engine. (In the early Hawkers there was no warning horn to catch the error.) If the gear select handle was in the UP position, starting an engine would power the hydraulics which would RETRACT the gear and the nose gear would be sucked up into the nose gear-well. It really gave the foolish crewmember a "sinking" feeling.

Our dear instructor-friend (Bob Lavery, who taught the wive's right-seater-course at the '07 convention) would ask the clients the following question:

"If you start the engine with the gear handle in the retract-position.... Will it raise the gear?"

In answer to his "trick-question" the knowledgeable clients would invariably respond "Yes!"

Bob would point out their error.... "No", he'd respond, "The gear would not be raised. Instead, the airplane will FALL to the ground."

HIs silliness made memorable the query.... which was his wonderful teaching-technique. (The BEST instructors not only taught you valuable skills... the BEST instructor is also the one who made the lesson memorable."
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
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lowNslow
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Re: Installed 180 Landing Gear

Post by lowNslow »

gahorn wrote:Doug, unless my brain is reversed again... placing a washer beneath the upper gearleg raises that wing instead of lowering it.
I was thinking the same thing, adding the washer under the gear would pivot the gear inboard and raise that wing.
Karl
'53 170B N3158B SN:25400
ASW-20BL
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canav8
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Re: Installed 180 Landing Gear

Post by canav8 »

Thanks,I am sorry. you are correct and I mis-typed. Yes it will raise affected side. As I said I am not using any shims at the fuselage/gear attach point with the 180 gear. Thanks to all ready to correct.
52' C-170B N2713D Ser #25255
Doug
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canav8
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Re: Installed 180 Landing Gear

Post by canav8 »

n2582d wrote:
canav8 wrote:The gear will move aft through use not forward. ... If the gear moves due to difficult landings like heavy crosswind landings and braking, the gear will eventually move aft. ...
I have thought the same thing so I was surprised to see wear marks at the forward end of my outboard landing gear extrusions. Maybe the castor angle drives the leg forward if the wedges are loose? Have others seen this?

Gary,I have no wear marks at the front of the extrusions. I do agree that improper toe in and not castor can cause wear at the front. That is another can of worms with alignment. In order for this to happen the gear has to be loose for it to move and service is required by the mechanic. When I got this plane the gear wedge shims were resting against the extrusion on top of the gear and the left gear leg clunked on landing and the tracking of the aircraft was unpredictable. It was bad. I was lucky that the extrusions did not need replacement. I added 2- .37 shims to the left side and all has all been fixed and it is happy tracking down the runway. Doug
52' C-170B N2713D Ser #25255
Doug
hilltop170
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Re: Installed 180 Landing Gear

Post by hilltop170 »

View of 170 landing gear wedges.

The outer gear box extrusion slot opening is big enough to accept gear of any thickness from the original 170 to 185. The wedges tapped into place keep the gear tight in the slot. Shims in addition to the wedges might be needed with thinner gear legs because without them, the wedges might not be thick enough to wedge the gear properly. The additional shims are not tapered and are stacked with the wedges to get the proper stack height to allow the wedges to hold the gear snug. The bolts only keep the wedges from working loose, they do not increase the wedge effect if they are tightened more tightly.

So, it is important, with no load on the gear, to tap the wedges home with a notched drift that will straddle the wedge bolt (can be fabricated from a 3/16" x 2" wide steel bar). Then snug the bolts against the shims/wedges. DO NOT try to drive the wedges home by tightening the bolts. There will not be any "clunking" sound when the gear is shaken when the wedges are installed properly.
Landing gear wedges properly installed
Landing gear wedges properly installed
Last edited by hilltop170 on Mon Apr 10, 2017 7:40 pm, edited 4 times in total.
Richard Pulley
2014-2016 TIC170A Past President
1951 170A, N1715D, s/n 20158, O-300D
Owned from 1973 to 1984.
Bought again in 2006 after 22 years.
It's not for sale!
hilltop170
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Re: Installed 180 Landing Gear

Post by hilltop170 »

Gear box details
Inboard gear box support and P-Ponk gear beef-up kit
Inboard gear box support and P-Ponk gear beef-up kit
Gear box area details with belly skin removed
Gear box area details with belly skin removed
P-Ponk replacement outer gear box extrusions
P-Ponk replacement outer gear box extrusions
Very tired 10,000 hour TT gear box outer extrusion with lots of wedge wear and obvious crack
Very tired 10,000 hour TT gear box outer extrusion with lots of wedge wear and obvious crack
Richard Pulley
2014-2016 TIC170A Past President
1951 170A, N1715D, s/n 20158, O-300D
Owned from 1973 to 1984.
Bought again in 2006 after 22 years.
It's not for sale!
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Poncho73
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Re: Installed 180 Landing Gear

Post by Poncho73 »

Old thread; however I’m doing the PPonk mod on my 48 now. I removed the right leg and noted there was one washer under the leg (to raise the right wing). What are the maximum amount of washers allowed under the leg at the top position. Without any washers the PPonk brackets are way to tight
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n2582d
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Re: Installed 180 Landing Gear

Post by n2582d »

The IPC list the number of shims as "as required". According to the Model 100 Series 1963-1968 paragraph 5-6 (b.), "Maximum number of shims permissible is three for the Models 150, 180, and 185. ... ."
Last edited by n2582d on Sun Jan 21, 2018 3:29 am, edited 1 time in total.
Gary
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canav8
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Re: Installed 180 Landing Gear

Post by canav8 »

Poncho73 wrote:Old thread; however I’m doing the PPonk mod on my 48 now. I removed the right leg and noted there was one washer under the leg (to raise the right wing). What are the maximum amount of washers allowed under the leg at the top position. Without any washers the PPonk brackets are way to tight
Hey Dave, I replied but your message box is full. can you empty your message box?
52' C-170B N2713D Ser #25255
Doug
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Poncho73
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Re: Installed 180 Landing Gear

Post by Poncho73 »

Emptied..
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ghostflyer
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Re: Installed 180 Landing Gear

Post by ghostflyer »

While we are looking at 180 and 185 gear replacements and fitment s ,my question is does the Cessna bird dog which is based on the 170 have the same legs or if different can they be fitted?
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GAHorn
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Re: Installed 180 Landing Gear

Post by GAHorn »

ghostflyer wrote:While we are looking at 180 and 185 gear replacements and fitment s ,my question is does the Cessna bird dog which is based on the 170 have the same legs or if different can they be fitted?
The PNs for the O-1A (L19) is 0641100-1 (L) and 0641100-2 (R). These are different numbers than the 180/185 gears frequently installed on 170s. A PDF file is found at this thread which describes the other gear legs: http://cessna170.org/forums/viewtopic.p ... on#p102308
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
hilltop170
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Joined: Sat May 06, 2006 6:05 pm

Re: Installed 180 Landing Gear

Post by hilltop170 »

ghostflyer wrote:While we are looking at 180 and 185 gear replacements and fitment s ,my question is does the Cessna bird dog which is based on the 170 have the same legs or if different can they be fitted?
L-19 gear legs will physically fit into the 170, 180, and 185.
L-19 gear are longer and more flexible than 180 and 185 gear.
L-19 gear are similar to lady legs in that they are side-specific, not symmetrical-are opposites, and can't be used on either side.
L-19 gear are flat on the long side, no arch.
L-19 gear will place the wheel further forward than stock 170 gear, so more weight on the tail.

Back when Ector Air in Odessa, Texas held the L-19 Type Certificate and was building brand new L-19/C-305 birddogs, I lived in Odessa and went out to their shop to see if I could buy a set of L-19 gear. I was going to try them on my 170. They would not sell me a set, said they only had enough sets to build the remaining planes they had parts for. Pete Jones at Air Repair has the rest of those parts now and is still building new Birddogs.

Back in those days, I had no idea and knew nothing about STCs, Field Approvals, etc so I was just going to put them on and fly.

I have always wondered how they would have worked on the 170. If anybody "knows", I would like to hear about it, privately, if the statute of limitations is still in effect.
Richard Pulley
2014-2016 TIC170A Past President
1951 170A, N1715D, s/n 20158, O-300D
Owned from 1973 to 1984.
Bought again in 2006 after 22 years.
It's not for sale!
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