80 Series Lancruiser - Caster correction plates vrs. drop brackets

Posted by Mark Hawley on Jun 16th 2021

80 Series Lancruiser - Caster correction plates vrs. drop brackets.

We lift our 80’s and the front axle tips forward a few degrees = caster is off, now the truck wanders on the road...Why?

The front of the 80 Series Landcruiser features two radius arms as links from the axle to the frame. These two arms use single bushings at the frame and twin bushings each at the axle. This provides a solid and proven front suspension on our North American FJ and FZJ80 Landcruisers (Yes the 105 Land Cruiser NOT sold in North America uses them too, but we are focusing on North America).

Alignment shops can NOT adjust the caster on an 80, when doing an alignment, only steering tow in/out and maybe center the steering wheel. So we have basically three options to correct the caster.

  1. Caster bushings
  2. Caster side plates
  3. Drop Brackets

Caster bushings: only adjust a small amount of caster, good for small lift adjustments. However they are the most involved process labor wise to install,let alone install correctly. Requires a strong shop press and install tool and fully removing both radius arms.

Caster side plates: provides 4* to 5* of caster, perfect for 3” to 6” lifts OR small lifts with very large oversized tires (larger tires like more caster in general). Easiest of the three to install, but does require notching the mount on the axle with a hand grinder.

Drop Brackets: mount at the back of the radius arm at the frame, lowering the mounting point of the radius arm, usually providing 4* to 6* of caster. Different types of drop brackets have been offered over the years, most bolt on some weld on. More involved install, potentially irreversible if removing the original mount to install drop brackets. Most aftermarket bolt on slides will NOT fit with drop brackets.

Caster bushings are minimal so we are going to focus on the other two options: Caster Side plates or Drop Brackets.

So do we go with Drop Brackets or Caster Side plates?

“Rock Hooks”

The drop bracket product died off in the US a while ago, drop brackets for the radius arms that is. Every now and then we see them “pop” up, usually being offered by a company from outside the US. Drop brackets are common overseas due to how trucks are used outside North America. For example outside North America sliders like we use are not common. Real sliders (for hard use) are mainly a North American thing since we will intentionally put our trucks into rocks, logs etc. (yes some areas across the globe will do similar but its not as common). Drop brackets earned the nickname in the US of "rock hooks" as you can go forward but when you try to go backwards, they hook onto obstacles on the trail. Even with slight ramping on their backsides, it hooks on a rock. Drop brackets for the 80 front Radius arms are in the perfect position just forward of the frame mid point to hang a truck up on the trail when you try to back up. We do need to go backwards sometimes. The other main issue with most drop brackets is that they interfere with bolt on sliders. Not just the proven Metal-tech 4x4 bolt on sliders that have been around since 2003 for FZJ80’s, but every primary competing slider that we know of. Bottom line real estate on the frame is in demand to be properly mounted sliders. This is a non-issue for parts of the globe that do not use sliders like we do, but in North America sliders are a key part of every 80 series build.

Caster Side Plates - Not all are equal

The best solution for caster correction on our 80 series is to use proper caster plates designed and made for right-hand drive trucks. (like the Metal-tech 4x4 Caster Correction kit, made for RHD trucks). The caster plate kits mount at the axle and move the front bolt of the radius arm down, this in turn tips the axle back thus correcting the caster lost from a lift. The install of side plates does require notching a small part of the bracket the radius arm mounts to, but this is easily done with a hand grinder. Best of all you do not have to remove the entire radius arms to install these kits!

WARNING: NOT all caster correction plate kits are the same for the 80. Some kits being sold in the US as “Australian” but made in China, are NOT made for left hand drive 80s. They are made for right hand drive 80s and do not properly fit when installing them.

Right hand drive or RHD 80’s (not US/CAN trucks) have the panhard bar (the bar parallel to the axle from the frame) mounting to the Left side of the axle. BUT the Left hand drive (US/CAN) 80s have the panhard bar mounting to the Right side of the axle. So why the issue? Well both trucks still have the differential in the same right side configuration. Caster plates for RHD 80’s use one large bolt to mount the upper part of the plates. With the panhard mount for the RHD (non US/CAN) trucks on the Left side of the axle you have any space to get the bolt in. But in the US/CAN the space on the axles Right side, has both the panhard bar mount AND the differential. Kits made primarily for North American 80’s like the Metal-tech 4x4 kit use two custom made 23mm bolts. By using two bolts we eliminated the fit issue of trying to get a long bolt past the differential or panhard mount at the axle, easy installation.

RHD caster kit (branded “Australian” yet made in China) not fitting a LHD North America FZJ80:

LHD caster kit (Metal-tech 4x4 kit, made in the USA) on a LHD North American FZJ80 running the Rubicon trail. Note the two upper bolts: 

Photos: Ryan Lewis

Written by: Mark Hawley

Mark is the founding owner of Metal-tech 4x4 that started in his garage in 2000 with $300. Mark has been a member of the TLCA since the early 90’s (Member #1137) and has been offroading and building most models of Land Cruisers for over 30yrs. 

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