Can Longer Shackle Straps be Added to Tandem Axle Trailer

Question

Question:

Hi I have a 2 axle trailer and I put 3 inch shackles on the front and back will it still work or is it not safe

asked by: Scott

0

Expert Reply:

When replacing shackle straps they should be the same length as the ones that were previously on your tandem axle trailer (if possible); replacing them with longer straps will result in additional play in your trailer suspension which could lead to additional wear or other issues and longer ones are not going to provide you with added benefit.

For a tandem axle trailer it is common to have 2-5/8" shackle straps such as part # 115052. I recommend using these if they were the same length as your previous shackle straps.

I added a link to our selection of shackle straps for you in case you had a different length, as well as a link to a help article on trailer suspension which I recommend checking out.

expert reply by: Kyle S

0

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Dean

3/10/2020

What if I have 3 shackle straps, can I go back to the 2.625 without any issues??

Chris R.

3/11/2020

Most likely this would be fine, but if the trailer currently uses 3" shackle straps it would be best just to stick with those to maintain current suspension performance. Is there a reason you want to move to shorter straps other than availability?

Dean S.

3/11/2020

I needed to replace all the bolts, bushings and straps because im rebuilding and saw on the website that most tandem axles are 2.625. so I just switched..

Chris R.

3/12/2020

I see - that makes sense. I don't think the shorter units will cause any issues. Just be sure they're still long enough to have a nice upward angle when unloaded.

Philip F.

3/10/2024

I have a question regarding spring position. I have an old Magic Trail boat trailer (twin axle) which I intend to renovate this year. It has 2x2 square axles and 20'' DE 3 leaf springs. The axles (with no load) appear are both slightly rotated and tip in toward the equalizer so the springs do not sit level. Is this normal / acceptable? The outermost hangers are about 2-1/4'' and the center hanger is 6" I was considering longer shackles but having read your earlier advice to Scott i'm not now sure.

Kyle S.

3/11/2024

@PhilipF Yep, this is normal. I would go ahead and keep the same length shackles as you have now.

Justin

9/9/2024

@KyleS what does it mean when the axels have no load and springs should sit level? I’m trying to figure out the correct shackles as I had one side with small and one side with big. Do I jack the whole trailer off ground then look at the springs and detrimen the correct side ?

Kyle S.

9/10/2024

@Justin Yes, that would be the correct move to determine right ones. You definitely want them all to be the same size.

See All (5) Replies to Philip F. ∨

Andy

12/22/2025

I have a 3500lb Tandem axle cargo trailer. There have been 2 times the shackles on one of the axles have flipped, (over extended). The most recent time when it flipped it broke the U bolts on the one side. Is there a way to correct this from happening, is this a common issue

Jesse M.

12/22/2025

@Andy Not exactly a common issue but it is typical for this to happen on tandem axle trailer when longer-than-stock shackles are used. What’s happening is the longer shackles are allowing too much suspension travel, which lets the equalizer and shackle rotate past their intended range. Once they flip or over-extend, the suspension can bind, and that shock load is often what leads to broken U-bolts or bent components, just like you experienced. Reducing the shackle length should fix this.

Jason H.

2/2/2026

@JesseMAre you talking about shortening shackle strap length

Jesse M.

2/2/2026

@JasonH Yes. Well to be more specific, I am talking about using shackles that are identical in size to the stock shackles. The stock suspension is built around a certain shackle size, and if the wrong size is used as a replacement it can throw the suspension out of center.

Answer 1

To slightly lower your trailer that has had an "axle flip" kit installed you would want to use slightly shorter shackle straps, not longer ones. Shorter shackles will let the axle rest closer to the trailer frame, which lowers the trailer…

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Answer 2

Well shackle length is mainly based on the height difference between the front and rear hangers. The rear hanger normally doesn't hang as low as the front so that the shackle can offset the difference and add the ability to move. What is the…

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Answer 3

Howdy Jason, for trailers over 6-1/2 feet wide, you’ll want either #e97XV 5 foot ramps or #e67XV 6 foot ramps. Both bolt directly to a wood trailer deck and include everything needed for installation. Between the two, ramp length is the deciding…

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Answer 4

The shackle straps included in the Lippert Tandem Axle Equa-Flex AP Kit - Wet Bolts - 3-1/8" Long Shackles #LC64FR you mentioned are 3-1/8" center to center and 4-3/8" overall length as shown in included diagram. Using the longer…

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Answer 5

Trailer manufacturers don't usually keep a record of parts like these that they install at the factory, so I cannot be sure as to the exact length of the shackle strap that would have come originally on your trailer. With this in mind, a 3-1/8…

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Answer 6

I recommend checking out the Dexstar Steel Mini Mod Trailer Wheel - 15" x 6" Rim - 6 on 5-1/2 - Silver Powder Coat #AM20539 which will be able to handle the weight capacity and psi rating when used with the Metal Valve Stem #AM20906.…

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Answer 7

Hi Mark; I recommend upgrading your shackles as well while you're at it using the Dexter Heavy Duty Suspension Upgrade Kit for Single Axle Trailers #K71-358-00. This includes wet bolts, bronze bushings, and 1/2" thick shackle straps so you…

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Answer 8

The first thing I would check on your trailer is the capacity of the springs. You need to be sure the spring capacity is rated at 1/2 the axle capacity. That way 2 springs equal the capacity of the trailer axle for proper fit. Check the arch of the…

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Answer 9

Hey Jp, welcome back! Since your trailer has 7,000 lbs underslung axles, you'll want the SumoSprings Trailer Helper Springs w/ Line Relocation Bracket item #SS33HR. This kit is rated for 5,000 lbs - 8,000 lbs axles so it's going to provide…

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Answer 10

If the shackle straps are within a 1/2" of what you normally had, say the 2-5/8" #115052 to 3-1/8" #TRSL313, you should be okay to install them. Just make sure that all of your shackle straps match though. If you are using the longer…

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Answer 11

Hey Barrett, ideally you have 2 inches of clearance between the tire sidewall and the frame of the trailer. Where you are at now is going to be not quite enough clearance. We don't have any wheel spacers and honestly 1-1/2 inch wheel spacers…

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Answer 12

You can use leaf springs that are rated higher than the axle without any issues as long as they measure the correct measurement for your trailer. For example the 6-leaf double eye spring for 7,000 lb axles part #e64SR measures 24-7/8" eye to…

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Can Longer Shackle Straps be Added to Tandem Axle Trailer

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