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

There is no specific torque rating for shackle bolts. You'll want to ensure that the bolts you use are long enough so that when installed you will have at least 2 threads protruding from the nut. Make sure that the bolt you're using has a…

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Answer 2

There is no specific torque rating for shackle bolts. Basically for the middle bolt there should be enough free play in the shackles to allow them to move. Tightening the shackle bolts too much will squeeze the shackle straps against the leaf springs…

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Answer 3

If there is a tiny bit of play in suspension components that are designed to move you would be fine. 1/16 of an inch isn't very much, and as long as you torqued everything down to spec you would be good to go. Ideally we just don't want it…

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Answer 4

Hey Darvin, we have the wet bolt part #126B2 which you can use for the suspension bolts on your trailer suspension. This is the standard size bolt that your axle suspension would have currently. Or are you looking for a kit that includes more…

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Answer 5

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Answer 6

Hey Aidan, a small amount of play is fine in your leaf springs. If the springs are sagging significantly then that could indicate that your springs are worn or there may be other suspension problems. If you notice any of that, then you are going to…

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Answer 7

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Answer 8

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Answer 9

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Answer 10

The length of the threaded portion of the cylinder is 1/2". However, when you put the rubber washer on the cylinder and the back nut on as little as possible, the remaining clearance is 1/4". I have attached two pictures showing this.

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Answer 11

Hey Anthony, you would want the Sumosprings kit part #SS68DR that is a confirmed fit for your 2020 Toyota 4Runner and then since you have a 3 inch lift you'd need a quantity of 6 of the spacers #A25723-90AH00 to take up that extra space created.…

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Answer 12

From the pictures you sent in it looks like the inner diameter of your Nev-R-Lube bearing is about 2" which means you'd need the 50MM Nev-R-Lube Bearing for 8,000-lb Dexter Axles #31-71-3. Aside from that you're basically just going to…

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