How Tight Should Shackle Bolts Be Tightened On Trailer

Question

Question:

I have just replaced the shackles, equalizers and bolts on my tandem 3500# Dexter axles. How tight do I make the shackle bolts? Do I bottom them out on the bolt shoulders or leave them a little loose so the assembly can move?

asked by: Tom P

1

Helpful Expert Reply:

There should be enough free play in the shackles to allow them to move.

There is no specific torque rating for shackle bolts. The first thing you should make sure of is that the bolts you use are long enough so that when installed you will have at least 2 threads protruding from the nut.

Next, make sure that the nut you are using is a locking nut, so that it cannot work loose and fall off.

If the bolt you are using has knurls at the bolt head you will want to tighten the bolt down until the knurls go through the shackle link or spring/equalizer hanger and the bolt head is flush. Then, back off the nut just a bit so that all of the components are pulled together but not so tight they cannot move.

I have attached a helpful article that explains trailer suspension you can check out. I have also attached a video about replacing shackle bolts you can take a look at.

expert reply by: Jeffrey L

1

Gilbert

5/11/2024

Very good information thank you

Cody

4/17/2025

Thank You, Sir! Good and straight to the point. I’ll go loosen my “way over tightened” shackles.

Chris R.

5/2/2025

@Cody No problem!

Neil

6/28/2025

@Cody Haha, I got on here just for this. Good to know.

Garvin C.

11/16/2025

I just replaced all 4 2200 lb leaf springs with 2500 lb leaf springs, New 1/2" U bolts. Both oem equalizers, thick shackles, Replaced reg bolts with wet bolts on a 2010 keystone cougar 278 RKS. 5th wheel. I torqued U bolts to 70 ft lbs. Equalizer hanger to 50 lbs. Shackle bolts to 50 ft lbs. I torqued everything while suspension was hanging. I put tires back on and put them on the ground. Do I need to loosen and re tighten anything before using ?

Robin H.

11/18/2025

@GarvinC as long as you used the correct torque spec for those parts you can leave everything as is.

Garvin

11/18/2025

Thank you. The previous Q & A before this one states a quite different procedure. I'm confused

Don B.

1/20/2026

If the nuts are not locking types can loctite blue or red be utilized?

Answer 1

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Answer 2

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Answer 3

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Answer 4

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Answer 5

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Answer 7

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Answer 8

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Answer 9

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Answer 11

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Answer 12

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How Tight Should Shackle Bolts Be Tightened On Trailer

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