Tailwheel Assy ATTACH bolts/nuts

How to keep the Cessna 170 flying and airworthy.

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n2582d
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Re: Tailwheel Assy ATTACH bolts/nuts

Post by n2582d »

Gary, thank you. I notice however, that instruction is not relative to the eye-bolt PN 062105 which is the subject of this thread. It appears to be with regard to a different bolt (as well as different washers) not specified in the illustration, which is accompanied by a seperate tie-down fixture.
Unknown.jpeg
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George, I'd encourage you to read paragraph 4-353 a little closer. It refers to Figure 4-29 on page 4-56. There the eyebolt (19) when crossed to the L-19 IPC fig. 54-9 comes up with p/n 0642105. Somewhere in this thread the "4" in the p/n got dropped. Might be helpful to edit previous entries to correct this.
p/n 0642105
p/n 0642105
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Gary
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GAHorn
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Re: Tailwheel Assy ATTACH bolts/nuts

Post by GAHorn »

Thanks..the typo is corrected.. Still, the L19 MX manual does not address the PN0642105 specifically, and the illustration is clearly NOT PN0642105... for whatever that's worth....
L19 Mx Manual Version w/special tie down attach (Item 33)  and spcl washers
L19 Mx Manual Version w/special tie down attach (Item 33) and spcl washers
L19 Illust. Parts Catalog with PN0642105 (Item 9)
L19 Illust. Parts Catalog with PN0642105 (Item 9)
'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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n2582d
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Re: Tailwheel Assy ATTACH bolts/nuts

Post by n2582d »

George, You are correct in that the top illustration, fig. 4-29A, shows a regular bolt rather than an eyebolt. This is the illustration "for all aircraft modified to 2800-pound gross weight configuration". I cannot find a matching description of this in the L-19 IPC. It is this configuration with the straight bolt (rather than eyebolt) that requires a torque of 650-700 inch-pounds and special washers on page 4-60A of the L-19 maintenance manual in paragraph 4-353 b.(1)-(3). You are correct, this does not apply to our use of the eyebolt. It might be a configuration the Alaska guys want to copy (with appropriate approval).

But the lower illustration you copied, fig. 54, from the L-19 IPC, matches fig. 4-29 in the L-19 Maintenance Manual. This is for "all aircraft not modified to 2800-pound gross weight configuration." This is the configuration that shows the eyebolt, p/n 0642105. Paragraph 4-353 a.(3) on page 4-60 and 4-61 calls for torquing this eyebolt to 600-650 inch-pounds.
Gary
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GAHorn
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Re: Tailwheel Assy ATTACH bolts/nuts

Post by GAHorn »

Thanks for this research, Gary! This is what the British would call "Good Duff!"

I edited my earlier comment which used the 100 Series manual to refer any reader to THIS page so as not be misled.

A point which deserves to be restated: Be certain that sufficient washers are installed on that AN7 OR PN0642105 eyebolt such that the nut actually tightens/torques properly and doesn't simply run-out of threads on the shank. This is especially possible with original 170 leaf springs and MAY be possible when using an L-19 leafspring.
'53 B-model N146YS SN:25713
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An originality nut (mostly) for the right reasons. ;)
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KG
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Re: Tailwheel Assy ATTACH bolts/nuts

Post by KG »

I continue to have problems with the eye-bolt on my tailwheel assembly becoming loose. I have sufficient washers stacked on the shank and a steel locknut but it works loose after just a few landings. I've started keeping a wrench in the plane to check it frequently.

I recently learned about Nord Lock lock washers. I'm considering having them installed on my tailwheel bolt to see if they will correct the problem. That and a witness mark so I can more easily detect it if it loosens.

Anyone have experience with Nord Locks? Any reason I wouldn't want to use them in this application?

I'm not at the hanger to measure it but according to this thread it's a AN 7 bolt which is 7/16. Is that correct? I apparently have to order a box of 10 of these and don't want to order the wrong size.

Thanks for any input.

Keith
53 170B
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GAHorn
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Re: Tailwheel Assy ATTACH bolts/nuts

Post by GAHorn »

It's difficult to comprehend how a self-locking nut would loosen if not jammed on the bolt-shank and not a worn-nut...
I wonder if drilling the eyebolt and using a castellated nut would be useful..
'53 B-model N146YS SN:25713
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An originality nut (mostly) for the right reasons. ;)
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KG
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Re: Tailwheel Assy ATTACH bolts/nuts

Post by KG »

gahorn wrote:It's difficult to comprehend how a self-locking nut would loosen if not jammed on the bolt-shank and not a worn-nut...
I wonder if drilling the eyebolt and using a castellated nut would be useful..
I thought the same thing. Perhaps the nut is worn out. I need to get it apart and find a solution before I break something.
53 170B
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Bruce Fenstermacher
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Re: Tailwheel Assy ATTACH bolts/nuts

Post by Bruce Fenstermacher »

It is and AN-7 and that is 7/16. Let us know how the Nord works Keith.
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gfeher
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Re: Tailwheel Assy ATTACH bolts/nuts

Post by gfeher »

I don't use the L-19 eyebolt but I do use a drilled bolt with a castellated nut secured with a cotter pin on the recommendation of an IA friend who regularly maintains a Bird Dog tow plane of a glider club. In his experience, he says, its the only way to reliably ensure that the nut doesn't loosen. I've not had any problems with mine loosening.
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Re: Tailwheel Assy ATTACH bolts/nuts

Post by 170C »

Keith, I experienced the same issue for many years. I would get the bolt tightened and after several landings the bolt would have turned 10-15 degrees. I added washers as George suggested, but that in of itself didn't cure the problem. Then George prompted me to make sure I was using the proper torque which I apparently wasn't using. I set my torque wrench to the suggested value (think it is 60 ft lbs?) and was afraid I was going to twist the bolt off before reaching the set torque (it didn't). That seemed to help a bunch. Maybe we can compare notes soon neighbor.
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karlclifford
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Re: Tailwheel Assy ATTACH bolts/nuts

Post by karlclifford »

I need to purchase a new L-19 eyebolt that attaches the Scott 3200 tailwheel assembly to the leaf spring. Does anyone know a supply source for this eyebolt. Thanks.
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n2582d
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Re: Tailwheel Assy ATTACH bolts/nuts

Post by n2582d »

Karl,
Welcome to forum! Air Repair has them. Their number is 622-846-0228. I think they may give a discount for 170 Association members. Could you ask them what torque they recommend for the the eyebolt when you order it?
Gary
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Re: Tailwheel Assy ATTACH bolts/nuts

Post by KG »

FWIW I had a new steel locknut with nord-lock washers installed and insured the proper torque was applied to my tailwheel bolt recently. I marked it with a sharpie pen and so far, after a few landings, it hasn't moved. I don't know which of the three things corrected the problem bit it seems to be ok now.

I researched the web for torque values and came up with anything from 54 to 65 ft/lbs for 7/16th bolts, grade 8. I had it torqued to 60.

I like the nord-lock washers.
53 170B
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karlclifford
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Re: Tailwheel Assy ATTACH bolts/nuts

Post by karlclifford »

Just ordered L-19 eyebolt from Air Repair. Thanks. Also ordered steel lock nut and nord lock washer.

No torque recommendation. Sorry.
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GAHorn
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Re: Tailwheel Assy ATTACH bolts/nuts

Post by GAHorn »

The 100 Series Service Manual recommends 460-500 in lbs (about 45 ft-lbs) for 7/16 with steel lock nuts.
'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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