Proper Landing gear axle attachment bolts

How to keep the Cessna 170 flying and airworthy.

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Byocum
Posts: 11
Joined: Sun Oct 07, 2018 11:42 am

Proper Landing gear axle attachment bolts

Post by Byocum »

At annual I removed wheel fairings and back plates to install some 8.00 x 6 tires. Still to be determined brand of tire im going to as most of my flying is from asphalt with some grass strips included. But the thing I noticed most was the 5 washers on the back side of the lady legs (1953 B Model) attacthing the solid aluminum axles. Can't be right? Can anybody stear me the way of the proper bolt and nut An numbers. Top two bolts are of smaller diameter. Also whats the most popular brand of 8.00 X 6 or 8.5 x 6 tires.
Brent yocum with new to me 170B
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lowNslow
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Re: Proper Landing gear axle attachment bolts

Post by lowNslow »

The top bolts are AN5-23A or NAS145-41 and the bottoms are AN6-24A or NAS146-42. The NAS bolts are recommended for ski installations and require a special washer as well.

As a new owner you may want to download the C170B parts manual https://support.cessna.com/custsupt/dyn ... dynVal=477
Its FREE!
Karl
'53 170B N3158B SN:25400
ASW-20BL
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ghostflyer
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Re: Proper Landing gear axle attachment bolts

Post by ghostflyer »

I use Michelin tyres and tubes . I replace the tube each time I replace the tyre because tubes wear also. We have many brands of tyres on aircraft that come through the shop and have found Michelin’s are the slowest to loose pressure over time and have the best wear characteristics. Those Tundra tires from Alaska look and work great but wear so quickly on hard surfaces and cost a arm and a leg. My axle attach bolts are all the same size and are all MS bolts . Those axle attach bolts will be all different lengths because of the different thicknesses of the shims for alignment.
Byocum
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Re: Proper Landing gear axle attachment bolts

Post by Byocum »

Thx for the info! My plane has the lady legs and no shims on either side.
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Bruce Fenstermacher
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Re: Proper Landing gear axle attachment bolts

Post by Bruce Fenstermacher »

Really, no shims. Is that even possible? I'd be looking into that.

BTW 8.50x6 are not on the TCDS so if you care, your looking at fishing around for paperwork to make them legal. 8:00x6 are on the TCDS.
CAUTION - My forum posts may be worth what you paid for them!

Bruce Fenstermacher, Past President, TIC170A
Email: brucefenster at gmail.com
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DaveF
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Re: Proper Landing gear axle attachment bolts

Post by DaveF »

I installed Air Trac 8.00x6 4-ply tires in June 2015 and have been extremely satisfied. They're much softer than the Michelin 7.00x6-6s they replaced, so they make landings a bit bouncier, but the softness is good on dirt and grass. I run 20-22psi operating mostly from concrete, and the tires have been wearing very well. I could run lower pressure, but I haven't experimented with it.
Byocum
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Re: Proper Landing gear axle attachment bolts

Post by Byocum »

Really no shims. Seems to track straight. But again it’s new to me. I only have about 3 hrs in the 170.
What kind of toe in is desired?
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c170b53
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Re: Proper Landing gear axle attachment bolts

Post by c170b53 »

Well , I don’t have any shims either and mine is ok on the ground as well (or so I think so). I’ve checked the alignment a few times didn’t need to re-adjust. I do have some of the outside wear pattern but it’s surviveable.
Jim McIntosh..
1953 C170B S/N 25656
02 K1200RS
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GAHorn
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Re: Proper Landing gear axle attachment bolts

Post by GAHorn »

Byocum wrote:Really no shims. Seems to track straight. But again it’s new to me. I only have about 3 hrs in the 170.
What kind of toe in is desired?
Zero Toe-in at 2,000 lbs is recommended by Cessna.
'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
Posts: 3481
Joined: Sat May 06, 2006 6:05 pm

Re: Proper Landing gear axle attachment bolts

Post by hilltop170 »

No shims with proper alignment would indicate a nice straight fuselage and straight gear, either from the factory or with proper rebuilds along the way.

No shims on my C180 either and it was wadded up into a ball by a tornado before I got it.
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!
Kurt Aichele
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Re: Proper Landing gear axle attachment bolts

Post by Kurt Aichele »

lowNslow wrote:The top bolts are AN5-23A or NAS145-41 and the bottoms are AN6-24A or NAS146-42. The NAS bolts are recommended for ski installations and require a special washer as well.

As a new owner you may want to download the C170B parts manual https://support.cessna.com/custsupt/dyn ... dynVal=477
Its FREE!
Karl,
What special washers? Looked everywhere, but couldn't find anything about a special washer.
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sfarringer
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Re: Proper Landing gear axle attachment bolts

Post by sfarringer »

These NAS bolts are a high strength bolt, and have a radius between the underside of the head and the bolt shank.
A special washer with a countersink that provides relief for the radius is required. Without the special washer, the regular washer can dig into the radius which creates a stress riser and compromises the bolt.

The 5/16 countersunk washer is NAS143-5C, which has been superceded by MS20002C5.
The 3/8 countersunk washer is NAS143-6C, which has been superceded by MS20002C6.
Ragwing S/N 18073
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Kevin Pearce
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Re: Proper Landing gear axle attachment bolts

Post by Kevin Pearce »

Karl

Thank you for posting the C170B parts manual link, very helpful.

Kevin
Kurt Aichele
Posts: 121
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Re: Proper Landing gear axle attachment bolts

Post by Kurt Aichele »

sfarringer wrote:These NAS bolts are a high strength bolt, and have a radius between the underside of the head and the bolt shank.
A special washer with a countersink that provides relief for the radius is required. Without the special washer, the regular washer can dig into the radius which creates a stress riser and compromises the bolt.

The 5/16 countersunk washer is NAS143-5C, which has been superceded by MS20002C5.
The 3/8 countersunk washer is NAS143-6C, which has been superceded by MS20002C6.
Thank you for the information.
Looks like your plane is a little older than ours, which has a serial # of 18118.
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