1. Trailer Leaf Spring Suspension
  2. Redline
  3. Suspension Bolts
  4. Spring Mounting Hardware
  5. 3 Inch Long
  6. 9/16 Inch Diameter
Shackle Bolt with Locknut for Double-Eye Springs - 3" Long

Shackle Bolt with Locknut for Double-Eye Springs - 3" Long

Item # 166081
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Our Price: $5.43
Trailer Leaf Spring Suspension
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Shipping Weight: 0.32 lbs
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Redline Spring Mounting Hardware - 166081
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9/16" Diameter spring-retainer bolt is used to mount double-eye spring inside front or rear hanger. Includes locknut. Lowest Prices for the best trailer leaf spring suspension from Redline. Shackle Bolt with Locknut for Double-Eye Springs - 3" Long part number 166081 can be ordered online at etrailer.com or call 800-298-1624 for expert service.
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Redline Trailer Leaf Spring Suspension - 166081

  • Suspension Bolts
  • Spring Mounting Hardware
  • 3 Inch Long
  • 9/16 Inch Diameter
  • Redline

9/16" Diameter spring-retainer bolt is used to mount double-eye spring inside front or rear hanger. Includes locknut.


Features:

  • Suspension bolt attaches leaf spring to front or rear hanger
  • Included locknut secures in place on bolt


Specs:

  • Diameter: 9/16"
  • Length: 3"


166081 Shackle Bolt with Nut





Video of Shackle Bolt with Locknut for Double-Eye Springs - 3" Long

Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.




Video Transcript for Redline Trailer Suspension 166081 Review

Today we're going to take a look at the 3-inch-long shackle bolt with the lock nut for double-eyed springs. This bolt will secure leaf springs to your front or rear hangar of your trailer's suspension system. Does include this lock nut to secure the bolt into place. Now the bolt itself is a grade-5 bolt. The overall length on this bolt if we measure it from the bottom of the head to the very end and see is going to be right at 3 inches. The bolt size is a 9/16th diameter by 18 threads per inch. The bolt head size is 13/16ths of an inch.

I got example here's a socket. You can see it will fit the head perfectly and then the lock nut which goes on the end right, the size on that is 7/8ths of an inch. You can see it fit rights into a 7/8ths inch socket but that should do it for the review on the 3-inch-long shackle bolt with the lock nut for the double-eyed springs.


Customer Reviews

Shackle Bolt with Locknut for Double-Eye Springs - 3" Long - 166081

Average Customer Rating:  4.9 out of 5 stars   (443 Customer Reviews)

9/16" Diameter spring-retainer bolt is used to mount double-eye spring inside front or rear hanger. Includes locknut.

- 166081
by:

I am very pleased with the quality and obvious necessary strength of these shackle bolts and the locknuts. I do wish the free shipping incentive was "Orders Over $50" vs $99 as well as a quicker turnaround for delivery. I ended up having my local trailer guy providing the 3 shackle bolts I needed but I will use these to replace the other 3 eventually and have one to spare. Overall though, I am pleased with this order and appreciate etrailer.com having the selection of components I needed.



- 166081
by:

Other than the parts taking a month to process, once they were gathered and packaged, they were delivered within 2 days! I replaced both sides with new 3-leaf double eye springs, 4 shackle straps, 6 shackle bolts, 2 Dexter U-bolt plates, and 2 U-bolts. They were really easy to replace and I did it quickly. Looks great, gonna take her out soon.



- 166081
by:

I replaced leaf springs on my trailer , springs , unbolts and leaf eye bolts were perfect fit and the job when easy the hard part was getting the old springs off. I know now to keep them siliconed up from now on for future problems.



- 166081
by:

I replaced my leaf springs, drums, brakes and added the Dexter E-Z Suspension kit to my Keystone Cougar Fifth Wheel trailer last year. This was my first time working with etrailer and I can’t say enough about how well it all went from the ordering to the install. Tammie P did a amazing job with knowing what parts would work best on my trailer. Tammie also gave me updates on my deliveries that I appreciated. I had a trip planned short after I received my parts. So having someone at their end checking on arrival dates helped. In the future I will definitely use etrailer for all my trailer needs. Thanks again for all the help! Great Team....



- 166081
by:

I bought springs, shackle bolts, and u-bolts and plates. Everything was great and fit perfectly. Only issue were the u bolts which were not galvanized. However, at a local trailer store, I bought galvanized U bolts for $4.50 each. For the DYIers, taking the old ones off took more than 4 hours for each side. My existing shackle bolts were so heavily rusted that I had to cut three off with a hack saw. Difficulty was confined space to operate hack saw with boat still on trailer. However, reassembling the new springs was less than 45 minutes each side. Must have tools are large diameter 3/4-13/16-7/8 deep sockets (6 point), 2 2 foot long breaker bars and a can of PB blaster. For safety: Good quality jack stands, minimum of 3--don't rely on the front trailer jack as it may roll. By the way, I did these myself and I am 64 years old.



- 166081
by:

I bought a used Jon Boat trailer and first time out the shackle bolt gave out. Perfect fit for my application and I really like the way the nut was made so that it locked on the bolt. I used these with the Never Fail Bushings. I had to drill out the shackle to accommodate this beefy bolts but that wasnt a big deal. I ended up doing both sides that had standard bolts instead of wet bolts. Not sure why only 2 were regular 3/8 inch bolts.



- 166081
by:

I replaced my leaf springs and shackles on my trailer and these bolts fit perfect. They come with lock nuts and they definately won't be coming loose. If I had to do it again I would have bought an impact wrench to make the job go quicker.



- 166081
by:

Grade of bolts are good for a leaf spring bracket.


Comments
Great hardware.
Ronald J - 06/24/2021


- 166081
by:

Installed all items and my boat trailer is like new. I was very impressed with your fast service and selection. I was able to find everything I needed in one place.



- 166081
by:

I was surprised how fast my last order arrived I needed the bolts to finish my leaf spring job , finished it and very happy with the exact replacement parts.



- 166081
by:

These shipped with some leaf springs. Box was received open(nothing missing. I suggest you consider doubling up the cardboard around the ends of the springs and taping all the edges completly



- 166081
by:

Great product, great service, can't say enough good things about trailer...


Comments
Still going strong!!! I dont really beat on my stuff. I was given a trailer that had seen better days, I rebuilt most of the mechanicals on it & its still serving me well…Thanks for the follow up though…
William - 01/21/2019



- 166081
by:

All of the products fit as direct replacements for the OEM products they replaced.


Comments
The spring set is working out well. I have had no issues.
Gordon - 04/29/2021


- 166081
by:

If you’re rebuilding your suspension this is the way to go. Very pleased with my purchase.



- 166081
by:

The bolts are top quality - exactly what I was looking for. Speedy delivery - even considering the border crossing into Canada.



- 166081
by:

I had rusted old bolts and leaf springs, these were great replacements. No issues look great work well and fast shipping.



- 166081
by:

It was a job to change it out but it has worke like new. Great job.



- 166081
by:

I purchased the 3000# axle springs and all mounting hardware to replace the old ones on my 1963 travel trailer. My trailer no longer leans to the left and goes down the road better than new. I should have done it many year ago. I received my package on time and installation was easy and fit perfect. Thanks Bridget



- 166081
by:

Much better than I can find locally


Comments
The trailer has not seen much use but it looks nice
Craig - 08/14/2021


- 166081
by:

I fixed my 5 wheel today with all the parts I got from you changed,all the equlizers and the shackles on both sides,my fifth wheel camper was blowing tires left and right.the shackles were almost wore all the way through the the end of the shackle.the tires were out of line with a straight line by two inches,when I got the new parts on the tires were right in line.thanks for the great prices and your web sight was easy to use and fast shipping I will be ordering from you again.thanks ron


Comments
The equilizers worked great I havent blown a tire yet thanks for all your help Ron
Ron A - 07/20/2016



- 166081
by:

100% satisfied as always. Great products and award winning customer service!



- 166081
by:

This was an amazing interaction: the woman who helped me couldn’t have been nicer and got me to the correct parts, they arrived within 36 hrs., and everything fit! Wow! Just about perfect. Thanks.



- 166081
by:

Great products. I have yet to install them. I ran into problems as the old shackle and spring perch bolts and nuts were tac-welded together. I've got to find a grinder.



- 166081
by:

AWESOME!!! Still going strong!



- 166081
by:

Fits the bill. Installed on a tandem utility trailer wit 3500 lb axles and double eye springs.


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Show More Reviews

Ask the Experts about this Redline Trailer Leaf Spring Suspension

  • Length of Redline # 166081 Suspension Shackle Bolt
    According to Redline, the # 166081 bolts are 3.1 inches long.
    view full answer...
  • Torque Specs for Redline Shackle Bolt with Locknut
    There actually is not a specific torque rating for shackle bolts like the Redline # 166081 that you referenced. You just want to make sure that the bolt is long enough so that when installed you have at least 2 threads protruding from the nut. This particular bolt measures 3 inches in length and the locknut is included. I have attached a short video demonstration that you can also check out.
    view full answer...
  • Torque Spec for 9/16" x 3" Long Bolt for Suspension
    There is not a specific torque requirement for bolts like the Shackle Bolt # 166081. You'll want to make sure that you're using a lock nut and ensure that the bolts you use are long enough so that when installed you will have at least 2 threads protruding that lock nut.
    view full answer...
  • Can Replacement Shackle Bolt Have Longer Thread Length
    I do understand your concern with the potential of a slightly longer thread length on the Shackle Bolt # 166081 causing the shackle strap to sit right on the threads. The fact is though that the shackle positioned there as opposed to the unthreaded shank is not going to cause much of a difference, if any. The shackle straps should not wear down any quicker because of this. As long as the bolt's overall length is correct then this will work perfectly for your trailer.
    view full answer...
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  • Availability of Wet Equalizer Bolts for a Joyrider Equalizer on a Prowler Trailer
    We do offer the wet shackle bolts you will need. The are the Wet Equalizer Bolt with Locknut and Grease Zerk, part # 126B2.
    view full answer...
  • Can Shackle Bolt with Locknut, # 166081 Be Used in Place of Dexter Bolts
    You will be able to use the Shackle Bolt with Locknut, # 166081, in place of the old Dexter bolts you have. If the bolts were shorter, you would not be able to use them but since they are basically the same length, you should not have any problems. I have included a link to a video on replacing shackle bolts that you may find helpful. We have numerous shackle links depending on what size you need. I have included a link to them for you to view along with a link to our FAQ articles on...
    view full answer...
  • Recommended Torque Specs for 9/16 and 1/2 Inch Trailer Suspension Hardware
    If you will be using 9/16 inch fasteners then torque them down to 110-114 foot pounds. If using 1/2 inch torque them to 76-78 foot pounds. You can find all sorts of different torque specs for the same size bolts or nuts and they will all be around these same figures. If you use Loctite use the blue kind, such as # LT37643, which will allow you to remove parts using hand tools. The red kind is going to be too strong. Also make sure the Loctite only goes on the threads and on any part...
    view full answer...
  • 9/16 inch Diameter Shackle Bolt Longer than 3 inches Availability
    We have the # 166079 which is a 9/16 inch diameter shackle bolt like you need that measures 3-1/2 inches in length.
    view full answer...
  • Shackle Bolt With Nut For 3 Inch, 3-1/2 Inch, And 3-5/8 Inch Length
    Shackle Bolt with Locknut for Double-Eye Springs - 3" Long, # 166081 and Spring-Eye Bolt with Locknut for Slipper Springs - 3-1/2" Long # 166079 both come with a nut. The Step Wet Bolt for 1-3/4" Double Eye Springs # 34007-187-00 does not come with the nut, however we have confirmed a fit with nut # 192600
    view full answer...
  • Shackle Straps Break on a 20ft Tandem Axle Trailer and the Rear Axle Slides the Tires
    One of the most common causes for shackle straps to break is over-tightening of the shackle bolts. If the shackle bolts are too tight, the shackle straps are not able to move with the suspension. This causes binding and it can bend or even brake the shackle straps, bolts and hangers. The sliding that you are experiencing on the rear axle is common for tandem and triple axle trailers and it is usually called scrubbing. The rear axle scrubs because trailer axles are not steering axles,...
    view full answer...
  • How Is the Shackle Bolt with Locknut for Double-Eye Springs 166081 Measured
    The length of the Shackle Bolt with Locknut for Double-Eye Springs part # 166081 does not include the bolt head, just the shaft. I have attached a photo below.
    view full answer...
    Image 1 for
  • Recommended Replacement Bolts and Springs for a 1961 Avion T-27 Tandem Axle Trailer
    We can definitely get you replacements for your 1961 Avion trailer. That being said, the closest spring we currently carry will be the Universal Group # SP-216275. This is rated for a 3,500 pound axle, but will be a 3 leaf spring and is only 23-1/8 inches long. In order use this, you would need to replace the front and rear hangers with something like # 115917. The Shackle Bolt and Lock Nut # 166081 will also be what I suggest to attach the springs to the hangers. We currently do not...
    view full answer...
  • Replacement 26 Inch Double Eye Leaf Springs and Hardware
    26 inch leaf springs have different capacities and aren't based on the number of leaves directly so it is better to determine the axle capacity and then get the 26 inch springs appropriate for that capacity regardless of the number of leaves. The weight capacity numbers represented on the title of your 26 inch options are the axle capacity number (or greater) and the springs will be 1/2 that capacity so when one is on each side the axle the capacity is that larger number. Springs rated...
    view full answer...
  • Correct Size Bolt for Dexter Axle 2K Double Eye Leaf Spring
    The Dexter Axle Double Eye Leaf Spring part # 072-017-00 is designed to be used with a standard 9/16" diameter shackle bolt like part # 166081 so that is the inner diameter of the bushing which is included.
    view full answer...
  • Torque Specs for Axle Spindle Nut, Suspension Hanger Bolts, and Lug Nuts for Trailer
    It looks like you might be asking about a few different torque specs so I'll address all of them separately. For a trailer axle spindle nut like part # 165686 you will need to run the spindle nut down until there is no more side-to-side play in the hub and then back it off to the next notch so you can secure the cotter pin, like part # 165649, through the spindle. When it comes to hanger bolts like the Redline # 166081 there isn't a specific torque rating either as you just need to...
    view full answer...
    Image 1 for
  • Replacement Leaf Spring Assembly for a Single Axle Cargo Trailer
    Thank you for the photos! They really helped. For your double eye leaf springs, the 4-leaf 25-1/8" Long, part # SP-212275, that you referenced are in fact the right ones for you. The reason they are slightly shorter than your current ones is because they tend to stretch a little over time. I've linked to a video installation of this spring for you to reference. Also, remember that you will need two. From your photo, it looks like you might have trouble with the existing hardware when...
    view full answer...
    Image 1 for
  • Can Suspension Wet Bolts Be Used with Both Nylon and Bronze Bushings
    You are correct that wet suspension bolts like # LC126238 are usually used along with bronze bushings for the longest possible service life but using them with nylon bushings is permissible. If standard bolts like # 166081 were to be replaced with wet bolts it would be fine to continue using the existing nylon bushings (for convenience) but in an all new installation bronze bushings would be preferred.
    view full answer...
  • Replacement Leaf Springs for Single Axle Trailer with 26 Inch Long Old Leaf Springs
    Correct, the loaded and unloaded length for a leaf spring will be different. In order to choose the correct replacement you will need to remove all weight from one side of the trailer and then measure the eye to eye spacing of that leaf spring. The new leaf spring you choose should then be very close to this but it can also be a bit shorter as leaf springs will flatten out over time as they wear. The most likely replacement we have for you is part # SP-220275 which measures 25-1/4"...
    view full answer...
  • Recommended Complete System Trailer Frame Down for Roadmaster Comfort Ride
    The Roadmaster Comfort Ride Leaf Spring Suspension Kit w/ Shocks - Tandem 8K, 3" Trailer Axles # RM-2460-2580 will fit any 3 inch diameter axles. The closest rated 3 inch diameter axles we have are the Dexter Trailer Axle w/ Electric Brakes - E-Z Lube - 8 on 6-1/2 Bolt Pattern - 95" - 7,000 lbs # 8327834-EB. This axle comes with the hubs and brake assemblies so as long a 80 inch on center spring seats work for your trailer, this will be an excellent choice. You will also need the...
    view full answer...
  • Double Eye Spring Recommendation and Suspension Parts for 6,000 Lb Trailer Axle
    The leaf spring I recommend is 6-Leaf Double-Eye Spring for 6,000-lb Trailer Axles part # SP-053275. These leaf springs come with 9/16" diameter nylon bushings installed. The amount of leafs do not matter as much as long as the spring is rated for your axle capacity. I recommend TruRyde Shackle Link part # TRSL225. The shackle straps are 2-1/4" long. The bolts you need are part # 166081. I also recommend curved equalizers part # TREQ356 that measure 6-1/8" long. We do not carry an equalizer...
    view full answer...
    Image 1 for
  • Which Replacement Equalizer and Shackles for 2004 Carson Dump Trailer with Axles 34" Apart
    In addition to the axle spacing, the best way to choose the appropriate equalizer replacement is by measuring how wide your current equalizer is when measured between the two side bolt holes, center on center; as long as you keep everything relatively close in length compared to the old parts, the geometry of your suspension system won't be thrown off. As long as your existing equalizer is 5-3/4" wide and your shackle straps are 2-1/4" long from bolt eye center to bolt eye center then...
    view full answer...
  • Comparing Bronze and Nylon Bushings for Trailer Suspension
    It really just depends on what you are looking to get out of the bushings. Bronze bushings, like part # K71-291-00, will last longer but are more noisy and it is recommended to use wet bolts like part # 126B2 to keep them lubricated. Nylon bushings, like part # SP05-060, are much quieter and can be used with regular bolts like part # 166081 since they don't need to be lubricated as much. As far as lifespan goes the bronze will last longer but not so much longer that they are much better...
    view full answer...
  • Replacement Trailer Suspension Shackles, Equalizers and Bolts
    We can help you with replacement trailer suspension parts for your Keystone Cougar. Our main page for suspension components is linked for you; on this you can select items like shackle straps, spring bushings, bolts and equalizers. Shackle strap # 115052 has a hole spacing of 2-5/8-inches, the closest to yours that we have. Overall dimensions are 4-inches x 1-1/4-inches and the bolt hole diameter is 9/16-inch. With this you can use standard bolt/nut # 166081 or wet bolt # 126B2 which...
    view full answer...
  • How to Pick Out Replacement Leaf Springs for 2007 Weekend Warrior Model CR3905
    I was able to find out that your 2007 Weekend Warrior model CR3905 is triple axle trailer with a GVWR of 16k. That means for each axle you'd need a capacity of at least 5,333 lbs. Which means you most likely have 6k axles. We have a few options for that capacity for leaf springs but you'll need to measure the length of your current springs to be sure. If you have 25-1/4 inch long springs you'd need part # SP111275. If you have 26 inch long springs you'd need part # SP-053275. If...
    view full answer...
  • Recommended Shackle Bolt for 2,000 lb Utility Trailer Leaf Spring Suspension System
    The Zinc Shackle Bolt with Locknut for Double-Eye Springs - 3" Long # TRFA73Z916DLNZ is a grade 5 bolt. Your setup as described is a standard setup for leaf spring hangers and double eye leaf springs. The # 166081 is made by the same manufacturer and is used more commonly than zinc plated for most factory applications. The cost difference comes down to supply and demand. The Dexter bolt # 007-003-01 is simply a different manufacturer that has a big name in the trailer axle market. ...
    view full answer...
    Image 1 for
  • Parts Needed to Replace 2000 lb Axle and Suspension
    You're certainly on the right track, with the exception of the leaf spring U-bolt kit. The # K71-385-00 is meant for a 3500 lb axle, and wouldn't fit your 2000 lb axle correctly. The U-bolts would be too large. If you want to keep the axle mounted under the leaf springs, you'll just need the # APUBR-10 U-bolt kit. If you were wanting to mount the axle beam above the springs which would lower the trailer's ride height by roughly 2 inches, you'd use the same # APUBR-10 bolt kit as well...
    view full answer...
  • Replacement Double Eye Leaf Springs for 7K Axles
    We do have an option for your 7k axles, but none with 7 leafs on them. At the end of the day the most important part is the appropriate capacity and length, since the leafs can be different thicknesses and grades of steel. With that said, if your current springs are roughly 24-7/8" long, you can use the # SP-198275 which are a double eyed spring with a 7000-lbs capacity. You will want to measure the current springs and make sure they're roughly the same length as these; you will want...
    view full answer...
  • Can I Replace 4 Leaf Springs With 5 Leaf Springs For The Axle On My Trailer
    Yes, you can replace your 4 Leaf Springs like part # SP-221275 with 5 Leaf Springs like part # SP-111275 as long as you replace all of the springs at the same time. There really isn't any advantage if you want to go with 5 leaf springs over 4 leaf springs. Typically, you always want to try to get the same parts to replace what you already have, but 1/8 of an inch difference per leaf spring won't make much of a difference in how everything fits together. The 5 leaf springs will work just...
    view full answer...
  • Leaf Spring and U-Bolt Kit for Dexter 4,000 lb Axle
    Yes the leaf spring part # SP-051275 would be the correct spring for your 4,000 Dexter axle. This is a very standard length trailer leaf spring at 26 inches and will work well on your trailer. Then for a U-bolt kit part # APUBR-1 would be what you'd need and then for shackle bolts part # 166081.
    view full answer...
    Image 1 for
  • Comparing Lippert Never-Fail Bushings to the Bronze Bushings and Wet Bolt Option for Tandem Axles
    The bronze bushings and wet bolts are a great option but they still do require maintenance especially under the conditions you referenced. There really isn't any new information in comparing it is basically the difference between maintenance required and zero maintenance. The Never-Fail bushings # LC279685 are maintenance free and self-lubricating so they will be a better fit for you. This kit comes with the bushings for 4 springs and two equalizers for a complete tandem axle trailer....
    view full answer...

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Info for this part was:

Employee Mike L
Expert Research:
Mike L
Employee Michael H
Expert Research:
Michael H
Employee Jameson C
Expert Research:
Jameson C
Employee John H
Expert Research:
John H
Employee Zack K
Video Edited:
Zack K
Employee Joshua S
Video Edited:
Joshua S
Employee Jeff D
Installed by:
Jeff D
Employee Nicholas E
Test Fit:
Nicholas E
Employee Alan C
Video by:
Alan C

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