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

Spring-Eye Bolt with Locknut for Slipper Springs - 3-1/2" Long

Item # 166079
lowest price pledge
Our Price: $9.16
Trailer Leaf Spring Suspension
Orders above $50 qualify for Free Shipping
Shipping Weight: 0.36 lbs
Quantity: 
In Stock
Redline Spring Mounting Hardware - 166079
zoom in icon
slider vertical icon
zoom out icon
Comment field cannot be left empty.
Name field cannot be left empty.

Thank you! Your comment has been submitted successfully. You should be able to view your question/comment here within a few days.

Error submitting comment. Please try again momentarily.

Product Images

In Use/Installed

Customer Photos

Videos

9/16" Diameter spring-retainer bolt is used to mount slipper spring inside front hanger. Includes locknut. Lowest Prices for the best trailer leaf spring suspension from Redline. Spring-Eye Bolt with Locknut for Slipper Springs - 3-1/2" Long part number 166079 can be ordered online at etrailer.com or call 800-298-8924 for expert service.
  • All Info
  • Reviews (232)
  • Q & A (26)
  • Videos (1)
  • Photos
  • Why etrailer?

Redline Trailer Leaf Spring Suspension - 166079

  • Suspension Bolts
  • Spring Mounting Hardware
  • 3-1/2 Inch Long
  • 9/16 Inch Diameter
  • Redline

9/16" Diameter spring-retainer bolt is used to mount slipper spring inside front hanger. Includes locknut.


Features:

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


Specs:

  • Diameter: 9/16"
  • Length: 3-1/2"


166079 Spring Eye Bolt with Nut - 3-1/2" Long

91635B





Video of Spring-Eye Bolt with Locknut for Slipper Springs - 3-1/2" Long

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




Video Transcript for Redline Trailer Suspension 166079 Review

Today we're going to take a look at the 3 and 1/2 inch long spring eye bolt with the lock nut for the slipper springs. Now this bolt will secure your slipper leaf 00:00:09 spring to the front hanger of slipper spring trailer suspension system. It does include this lock nut to secure the bolt into place. A few specs on this, the bolt is a grade 5 bolt. Overall length which would be measured from under the head to the very end, is going to be right at 3 and 1/2 inches long. The bolt size is a 9/16 diameter by 18 threads per inch.

The bolt head size is 13/16 of an inch. I've got an example, here's a 13/16 socket and you can see it fits exactly onto the head of the bolt, as in the lock nut which goes on the inaudible 00:00:45 here. The size of the lock nut is going to be a 7/8-inch head and there your 7/8-inch nut on there. That should do it for the review of the 3 and 1/2 inch long spring eye bolt with the lock nut for slipper springs.


Customer Reviews

Spring-Eye Bolt with Locknut for Slipper Springs - 3-1/2" Long - 166079

Average Customer Rating:  4.8 out of 5 stars   (232 Customer Reviews)

9/16" Diameter spring-retainer bolt is used to mount slipper spring inside front hanger. Includes locknut.

- 166079
by:

The replacement parts fit perfectly and were very easy to install. Fast shipping. 711309



- 166079
by:

The bolts are a heavy grade 8 bolt and have the ridges by the head of the bolt. These are handy as the dig in and help the bolt from slipping as you tighten it. Even though it is listed as an add on item for the 1 3/4 leaf spring set, the bolt is slightly to long for this application. You will need to put washers on so the nut will tighten. 636985



- 166079
by:

Great Experience! When I noticed that the leaf springs on my 44 year old boat trailer had cracked I thought I would never find replacements. I fully expected to have to have something custom built. I was amazed when I found the fantastic diagrams/descriptions dimensions for replacement springs on etrailer.com The phone support person was wonderfully helpful in confirming if items were in stock and ready to ship. The replacement springs arrived on time and everything bolted up perfectly! Thanks for such a great site! 84055



- 166079
by:

Perfect 918425



- 166079
by:

Fits perfectly 908329



- 166079
by: 11/04/2020

907813



- 166079
by:

Easy ordering. Arrived quickly. Absolutely no problems with the parts. etrailer.com will be my go to for my trailer parts from here on out. 895871



- 166079
by:

893859



- 166079
by: 09/25/2020

Parts worked great, shipping was quick and on time. 892356



- 166079
by:

Exactly what we expected. Functional web page easy check out prompt shipping information. 875237



- 166079
by:

The bold is fine but it was the wrong one for my application. I believe I should have ordered Item # 166079. Even looking back Item # 166079 does not have enough description to indicate the non threaded length or that it's made for 1 3/4" spring hangers. 866651



- 166079
by: 08/14/2020

861695



- 166079
by:

Great idea having your people explain on video how each item works and how best to complete the replacement part 860688



- 166079
by:

Fit perfectly 856548



- 166079
by:

Exactly as I was expecting. Shipped same day I ordered. 855229



- 166079
by:

Work great 852145



- 166079
by:

Excellent bolt for 2" slipper Spring It locks into place Securely 846259



- 166079
by:

Product is as always with etrailer good and delivered and stated. Even during these times. We buy from etrailer often and you can’t go wrong! 840113



- 166079
by:

Excellent product and is holding up very nicely, I would recommend this to everyone who needs this 837170



- 166079
by:

Worked great. 831444



- 166079
by:

Bushings fit perfect and paired with greaseable bolts work great 844532



- 166079
by:

Bolts sent were too long for my application so I had to buy some Grade 8 washers to use as spacers. 828520



- 166079
by:

Needed these for a leaf spring installation. They were the perfect fit. 820172



- 166079
by:

Fit perfectly great price 817682



- 166079
by:

Little longer than the stock bolt for my trailer. Had to use 2 washers 816315


26
235
Show More Reviews

Ask the Experts about this Redline Trailer Leaf Spring Suspension

  • Where is the Length of the Bolt part # 166079 Measured
    The 3-1/2 inch length of the bolt part # 166079 is measure from below the head of the bolt to the end of it. Based on what you mentioned this should work well for you.
    view full answer...
  • How to Determine Correct Slipper Spring Replacement for 1,500 lb Axle
    What happens to slipper springs is that over time they elongate and flatten out, particularly if your springs are considerably older. The most important measurement you mentioned was the 26 inches from the center of the spring eye to the end of the spring. Based on that the closest slipper spring we have that could work is the 3-Leaf Slipper Spring w/ Radius End for 1,500-lb Trailer Axles - 24-5/8" Long # SP-178275, which would work if you had a tandem-axle trailer. There are no slipper...
    view full answer...
  • Replacement Suspension Components for 6,000 Lb Axles with 25-1/4 Inch Long Leaf Springs
    Thanks for the photo! I have everything you need to get your trailer back on the road. I have attached my recommendations on the following parts for you trailer as well as the quantities needed. Leaf Springs: part # SP-111275 (4) Equalizers: part # TREQ310 (2) Shackle Straps: part # 115208GALV (8) U-Bolts: part # APUBR-8 (2) Eye Bolts: part # 166079 (12) I have also attached a few review videos on the above products for you as well.
    view full answer...
  • Recommended Slipper Spring for Custom Kayak Trailer
    Thanks for the photos with measurements. The 2-Leaf Slipper Spring w/ Radius End for 1,000-lb Trailer Axles - 24-5/8" Long # SP-177275 are rated for 500lbs each for use with a 1000K axle. This will work with the inside to inside measurement you are seeking. You will simply need the 9/16 inch bolt # 166079. If there is any extra space in the hanger it won't be an issue with the bolt and bushing.
    view full answer...
  • Correct Bushing and Bolt for 4-Leaf Slipper Spring # SP-264275
    The 4-Leaf Slipper Spring # SP-264275 that you referenced actually comes included with the nylon bushing but if a replacement is needed then the 9/16 inch # TRBU11561 that you mentioned would be the correct size and will work perfectly. The correct bolt for this setup is the Redline Spring-Eye Bolt # 166079 that features a 9/16 inch diameter and 3-1/2 inch length.
    view full answer...
  • Axle Spacing When Using Slipper Spring Equalizer Kit # APT6SE with 26 inch Long Leaf Springs
    Based on your leaf spring length the axle spacing you'd have with the hanger kit part # APT6SE would be right at 33 inches. This kit is designed for use with 9/16 inch bolts like the # 166079 and we would not recommend drilling out the kit to fit a wider bolt.
    view full answer...
  • Replacement Trailer Suspension Parts for Trailer with 2 Square Axle
    It looks like you've got a pretty good grasp on all of this and thank you for the detailed information; it looks like most of the parts you've mentioned will work for you. For the leaf springs, the 26" long # SP-051275 will be the best option for you since springs stretch out over time and they're right around the capacity of what the axles likely is. The next closest size would be the 25-1/8" # SP-212275, but I would be hard pressed to believe that your old ones have stretched out over...
    view full answer...
  • Bushings for Slipper Spring with 1/2-Inch Inner Diameter
    The nylon bushing is included with Slipper Spring # SP-178275. The bushing has an inside diameter intended for a 9/16-inch bolt like # 166079. I linked a page showing all suspension bolts in this diameter. For a bushing with a 1/2-inch inner diameter and the 11/16-inch outer diameter required for this spring you can use # TRBU11506.
    view full answer...
  • Correct Track Alignment Replacement Hanger Bolt Recommendation
    What you'd want is the replacement suspension bolt part # 166079. This is 9/16 inch in diameter like you need and is 3-1/2 inches long too. It comes with matching nut as well.
    view full answer...
  • Bushings, Shackle Straps, and Wet Bolts for Tandem Axle Trailer
    The bronze bushings with 9/16 inner diameter come as a single, # D014-077-00, or in a pack of four, # K71-291-00. The closest shackle strap we have to that length is 3-1/8 inches. I've linked our selection for you. We do carry a heavy-duty strap that's 3-3/4 inches long, part # 018-026-05. We have wet bolts that are 3 inch, # 126B2, but the 3-1/2 inch long bolt that will fit the 9/16 inch bushing is not a wet bolt, # 166079. All of the prices can be seen on the linked product pages.
    view full answer...
  • 12 Inch Slipper Spring Equalizer Kit Recommendation
    The only 12 inch slipper spring equalizer we offer is the part # E4541-Z. For shackle bolts you would need the part # 166079, for equalizer bolts you would need # TRFA71063, cotter pin part # 165649, and for spring keeper bolts part # 7-7. We do not have all of this in a kit though.
    view full answer...
  • 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...
  • Are there Bolt-On Hangers for Trailer Leaf Spring Suspension
    We do have a couple of bolt-on spring hangers # CE14017G and # CE14016G but they are designed for slipper springs and not double-eye springs like # SP-124275. Its not likely that professional welder would charge that much. You might be able to find one locally via an iron workers union near you. For u-bolts for your 1-1/2 inch square axle you can use # SP01-120 for 2 u-bolts and 4 nuts. For a u-bolt plate you can use # 115983. For a hanger kit you could use # APS1. Now what you could...
    view full answer...
  • Bolts Needed To Install Slipper Springs
    For the spring eye you would use the Spring-Eye Bolt with Locknut for Slipper Springs - 3-1/2" Long # 166079, but slipper springs don't have the second spring eye, so a bolt is not used on the back end. You can also use a wet bolt like # 126B2, for less friction. The Shackle Bolt with Locknut for Double-Eye Springs - 3" Long # 166081 are for use with the spring and shackle straps used with a shackle straps on a tandem setup with an equalizer but it could be used for the springs and the...
    view full answer...
  • How to Determine the Correct Slipper Spring for 6,000 lb Axle
    The slipper spring we carry for 6,000 lb axles is the 5-Leaf Slipper Spring w/ Hook End # SP-160275. To figure out if this spring is going to work for you there is a measurement you will need to take. If you look at the accompanying diagram you can see that "C" is 27 inches. This is the length from the center of the eye to the end of the spring with the slipper; you can measure your current slipper spring to see if you have a similar measurement, keeping in mind that the current spring...
    view full answer...
  • Replacement Slipper Spring for Boat Trailer 1000-lb Axle
    Well-worn leaf springs can become elongated and actually measure longer than their length when new. It is not uncommon for a leaf spring to get as much as 3/4-inch to 1-inch longer from years of use. If your spring measures 25-1/4-inches long then chances are that when new it was indeed the 24-5/8-inch length of the Redline # SP-177275. This 2-leaf spring is rated for 1000-lb trailer axles; you can check the sticker on your axle to confirm it's weight rating. This spring does indeed...
    view full answer...
  • Recommended Bolt On Hangers For Aluminum Frame Trailer
    Since you've got an aluminum frame trailer, I understand why you're looking for a bolt on solution. The only available bolt on hangers we have available would be the # CE14017G and # CE14016G but they are designed for slipper springs and not double-eye springs like # SP-124275 you were looking at. If you went this route you would want to use something like the # SP-040275 as your springs, which have a 3700-lbs capacity. This would be the best solution available for your new aluminum...
    view full answer...
  • 2 Inch Wide Replacement Equalizer for Slipper Springs on Seven Thousand Pound Triple Axle Trailer
    The TruRyde # TREQ1344 Equalizer for 2 inch wide Slipper Springs that you referenced is considered a fit for the dimensions that you listed on your triple axle trailer with seven thousand pound axles. I would recommend replacing the entire equalizer instead of welding in new bushings. You indeed would need 4 equalizers for your triple axle trailer. The total length (a) and the length from the center of the front bolt hole to the center of the middle bolt hole (b) is slightly off when...
    view full answer...
  • Single Slipper Spring for Tandem 6000 Pound Axles 2 Inches Wide
    To determine the appropriate replacement slipper spring you would need there are a few measurements that are crucial. In order to get these measurements the current spring cannot have a load on it. If you have already removed the slipper spring from the trailer that works great. Or you can measure while it is on the trailer, just make sure that when you jack the trailer up you do so by the trailer frame. Also, make sure it is safe and secure before taking your measurements. The...
    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...
  • Bolt Recommendations for a Equalizer for 2 inch Slipper Springs
    For the Equalizer for 2 inch Wide Slipper Springs # TREQ1344 you will want to use a Wet Equalizer Bolt with Castle Nut and Grease Zerk # TRFA71063 for the center bolt hole. This bolt has a grease (zerk) fitting. For the side bolt hole that the spring will mount to you will want to use a Spring-Eye Bolt with Locknut # 166079. For a keeper bolt you would want a Leaf Spring Center Tie Bolt with Nut # 38-4TB. I attached an FAQ article on slipper spring suspension setups for you to...
    view full answer...
  • Hanger Bolt Recommendation for a 3-Leaf Slipper Spring # WIE3
    You need to use a 9/16 inch bolt for the front eye of the 3-Leaf Slipper Spring that your referenced part # SP-178275. For that I would recommend the Spring Eye Bolt with Lock Nut part # 166079. The correct rear hanger is part # 115706S if it's a single axle trailer. Since the spring does not have an eye on the back of it you do not need to match a 9/16 inch bolt to anything.
    view full answer...
  • Recommended 30 Inch Slipper Springs and 2 Inch Square Axle Mounting Kit
    For your 2,000 lb square axle, I recommend the 3-Leaf Slipper Spring w/ Flat End for 2,900-lb Trailer Axles - 30" Long # SP-039275 which is a little stronger than your axle but won't increase your capacity of 2,000 lbs. This is a 30 inch long slipper spring with a 1.75 inch width as you stated. I recommend using the Spring-Eye Bolt with Locknut for Slipper Springs - 3-1/2" Long # 166079 with each spring. For your square axle mounting, I recommend the CE Smith U-Bolt Kit for Mounting...
    view full answer...
  • Recommended Shackle Bolt For Escort Trailer
    The shackle bolt we offer that measures 3-1/2 inches is part # 166079. This is a 9/16 inch diameter bolt and includes the locknut. We do not offer a shackle bolt that measures 9/16 inch x 4 inches.
    view full answer...

Do you have a question about this Trailer Leaf Spring Suspension?




  • Why etrailer.com?

    At etrailer.com we guarantee:
  • Highest quality trailer leaf spring suspension for the best price.

    Our Lowest Price Pledge ensures you will never overpay for the parts you need.
  • Real product know-how.

    We make sure that the products we sell are what we say they are, and that they work the way they are supposed to work. Get real advice from a real person who has the knowledge and expertise needed to solve your problem.
  • Most detailed, accurate trailer leaf spring suspension information available.

    Because we take providing accurate product information seriously, we take our own detailed product photos, demo videos and installation videos, as well as verify measurements, instructions, and vehicle fit information.
  • Installations, made easy.

    We love helping people and have the most highly-trained customer service, hands-on experience, step by step videos and installation instructions.
  • Fast shipping.

    Your order is automatically routed to get out of our warehouse and to your door as quickly as possible. Receive free shipping on orders over $99.
  • Personalized service for life.

    We provide one-on-one, personalized service from the ordering process through the life of your product.
  • Trusted since 1946.

    We've been serving customers since our parts store first opened in 1946 and continue to be recognized by our customers, our vendors and third parties for exceptional service.
  • Returns Policy

    Need to return an item? No problem. Please read our Returns Policy for more information.

Info for this part was:

Installed by:
Jeff D
Installed by:
Randy B
Expert Research:
Jameson C
Video by:
Kathleen M
Updated by:
Sarah W

At etrailer.com we provide the best information available about the products we sell. We take the quality of our information seriously so that you can get the right part the first time. Let us know if anything is missing or if you have any questions.


Product Experts Available Now!
Call 800-298-8924