Formula U-Bolt Toyota Landcruiser 45 47 75 78 79 Series

Formula U-Bolt Toyota Landcruiser 45 47 75 78 79 Series

The Importance of U-Bolts

The humble U-bolt is crucial for your vehicle's suspension, especially if you have leaf spring suspension. It secures the leaf springs to the differential, which houses the axles and keeps your wheels and tires on the road.

Why Replace U-Bolts?

• Seized or Broken U-Bolts: Old U-bolts often seize or break, requiring cutting for removal.
• Damaged Threads: Removing old U-bolts can damage threads, leading to loose U-bolts and voided warranties.
• Incorrect Length: Stronger leaf springs may need longer U-bolts.

Essential Questions About U-Bolts

• Shape: Square, round, or semi-round.
• Material Size: Measure the rod's diameter at the thread.
• Inside Measurement: Ensure it fits over the differential or spring pack.
• Leg Length: Measure from the underside of the top to the leg end.
• Thread Length: Ensure enough thread for secure fastening.
• Material Grade: Use high-grade materials for durability.

Tips for U-Bolt Replacement

• Re-tension: Re-tighten U-bolts 7-10 days after installation to secure the springs.
• Correct Fit: Ensure U-bolts match your vehicle's specifications.

Please check your model & the measurements as listed below before purchase.

Vehicle Compatibility

• Toyota Bundera 75 Series 1985-1999
• Toyota Landcruiser 42 Series 1979-1984
• Toyota Landcruiser 45 47 Series 19801986 Large Spring Eye
• Toyota Landcruiser 75 Series 1985-1999
• Toyota Landcruiser 78 Series 1999-2007
• Toyota Landcruiser 79 Series 2007-On

Measurements

• Inside Leg Length: 230mm
• Inside Leg Width: 83mm
• Material OD: 14mm

Sold as a SINGLE unit. If you require more than one, please add the required amount to your cart.

Why cant I re-use my U-Bolts?

When supplying a leaf spring kit, spacer lift kit or a full suspension lift kit, we are often asked whether the original equipment (OE) U-bolts can be reused.

We get a variety of reactions when we advise our customers that new U-bolts should be used, however there are some very specific reasons why we stress this point so much, trying to sell you something you don’t need is not one of them.

Reason 1: U-bolts are often a torque to yield bolt.

This means when you tighten a U-bolt to its correct torque spec, the bolt stretches to achieve that level of tightness. However, the U-bolt can only stretch so far, each time the U-bolt is tightened, it is closer to failure. To us, it’s not worth the risk.

Reason 2: Used U-bolts don’t tighten the same as new U-bolts. 

The next issue with reusing U-bolts has to do with the threads themselves. When being tightened, the threads are deformed under the torque. Each time the U-bolt is tightened the threads are cut and grooved by the nut as the nut is tightened around them. This damage creates an opportunity for the U-bolt to loosen over time. Corrosion, dirt, oil and wear increase friction on the thread, so even when tightened to the correct torque spec, clamping force is decreased and may not securely hold the leaf pack.

Reason 3: The original U-bolts are generally too short for aftermarket leaf springs.

We often encounter loose axles and damaged suspensions due to the U-bolts simply being the wrong size. OE U-bolts are not long enough to fit over aftermarket leaf spring packs and cannot be tightened properly. Aftermarket and/or raised leaf spring packs are typically thicker with more primary & secondary leaves in the pack, this is because most aftermarket leaf springs are designed to carry heavier loads and/or raise the vehicle. Please see the below diagram showing thi

Reason 4: We know our U-bolts are the best. 

A high-quality U-bolt will be made of high-grade hardened steel and have rolled threads instead cut threads. Rolled threads offer a larger diameter than the shaft of the bolt, resulting in more core material and strength. Lower quality U-bolts are often made with cut threads which are cut from the shank of bolt resulting in reduced material thickness. Cut thread U-bolts are never a good idea to use because the threads tend to strip. Additionally, this means the U-bolts won’t be able to achieve near the torque spec that a rolled thread U-bolt can.

The smallest amount of looseness or vibration in your U-bolts will allow for movement between your axle and leaf springs. If you have a spacer lift kit, this movement multiplies. Over time, a small amount of movement will always become a larger problem. It doesn’t take much movement before centre bolt heads begin to shear, or you run the risk of warping your axle seats. We’ve seen this and much worse happen over the years as a result of reused U-bolts coming loose.

You know what all the above situations almost always had in common? The U-bolts were either loose, reused, incorrectly sized or low-quality U-bolts.

Remember, your U-bolts are what holds your axle onto your vehicle. Having your axle come loose can not only be very damaging and expensive to repair, but it can also be very dangerous for you and those who share the road with you. We’ve seen everything from axles that have tracked to the side and allowed the rear of a vehicle to steer itself, all the way to axles that have torn themselves right out from underneath the vehicle they were supposed to be secured to.