How tight should rear shackles be made?

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DHort
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How tight should rear shackles be made?

Post by DHort » Wed Jun 30, 2021 10:02 pm

Should they be tightened all the way and then backed off until you can install the cotter pin or should they be backed off more than that?

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RajoRacer
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Re: How tight should rear shackles be made?

Post by RajoRacer » Wed Jun 30, 2021 10:26 pm

I snug mine up to verify the shackle is "home" then back off the nut a hole or two.


Allan
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Re: How tight should rear shackles be made?

Post by Allan » Thu Jul 01, 2021 12:24 am

The shackle pins are stopped, with a smaller thread. they should be done up until the legs are tight or the keeper is tight. If this makes them too tight in the spring/perch, the bushes need to be faced of a bit to allow them to move. They should not be left with the nut free to move on the cotter pins.

Allan from down under.

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DanTreace
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Re: How tight should rear shackles be made?

Post by DanTreace » Thu Jul 01, 2021 10:38 am

Allan is correct, the shackle and its plate set the proper distance, if when fitted is too tight that the spring won’t bounce with the moving shackle, then spring leaf loop end, or bushing face needs work.

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Check to be sure plate holes are clear and plate can slide all the way up the pin.
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Plate fully on shackle and nut on threads close up firm and allow cotter to be fitted.
The best way is always the simplest. The attics of the world are cluttered up with complicated failures. Henry Ford
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Re: How tight should rear shackles be made?

Post by RajoRacer » Thu Jul 01, 2021 6:35 pm

Whatever works so as there is no hindrance of the shackle movement !


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Re: How tight should rear shackles be made?

Post by Allan » Thu Jul 01, 2021 8:11 pm

Cotter pins are used to stop a tensioned nut from backing off. They are not used to keep a non tensioned nut from backing further off. I can think of one exception to this on a T. The fan arm to timing cover bolt is also stepped so it is tensioned up to the timing cover, the block casting acting as the nut. In this application, the cotter pin just stops the shaft winding out too far if it gets loose.

Allan from down under.

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