Toyota Land Cruiser FJ60 and FJ62 Chromoly Birfield Axle Guide and Comparison

Also see:

• Can I Drive On a Broken Birfield?
• Toyota Birfield Upgrades: All About Chromoly, 30 Splines, and Fit For Minis, Pickups, 4Runners, and Land Cruisers

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60 Series Land Cruisers are one of the workhorses of the Land Cruiser models. If you like Toyotas, they were (and are) one of Toyota's few solid axle models that could go fourwheeling while hauling lots of extra gear and people. And 60s are way more comfortable than 40s or even 55s. But there may come a time when you realize you need better Birfields. Larger tires and large loads put a tremendous strain on the stock axles. Consider also that your fj60 or FJ62 runs the same size Birfield as the much lighter solid axle Toyota pickups and 4Runners.

It's not hard to see why you'd want a Birfield that won't explode when you're miles from anywhere on a family outing.


Early on, it was a struggle for manufacturers to figure out how to make a stronger Birfield axle, but soon they settled on a thicker bell and 4340. From there, other parts in the axle started to break, so now we've got axles (at different price points) with 4340 chromoly, larger spline counts,  300M, and different heat treats. Here is the info you need on ALL chromoly FJ60 axle sets and the differences between the myriad options.


FJ60 and FJ62 Axle Basics

First of all we're going to be talking about Toyota Land Cruiser FJ60 ('81-'87) & FJ62 ('88-'90) front axles. Fortunately for us, these axles were the same through all years of manufacture, meaning you can put a 62 axleshaft into a 60 housing (or vice versa). The shafts are virtually identical. 60 Series Cruisers have a longer WMS to WMS than earlier Land Cruisers by about 3". FJ80 front axles are very different from any other Toyota axle.


Stock FJ60 axles are "27 spline". They have 30 splines at the hub, 27 at the Birfield joint, and 30 at the differential.


You'll see below that there are two classes of aftermarket axles: plain ol' chromoly and chromoly with some extra stuff. If you just need some basic strength for your weekend wheeler, generic 30 spline axles are fine. If you're running much larger tires with lots of horsepower and/or tend to beat on your rig, you'll want to consider with more heat treating or 300M.


What Makes a Strong Birfield?

There are three characteristics that'll make your front axleshafts stronger. They are materials, spline count, and heat treatment. We don't look at diameter separately because an increase in spline count automatically gives you a larger diameter.


Toyota Land Cruiser Axle Spline Counts

If you want to know about stock Toyota Birfields, spline counts, how the parts go together, and more, check out our article on Toyota Birfield axles. If you want the quick version, here it is:

There has been 1 stock spline count configuration for FJ60s and FJ62s. Starting from the hub side it is:

30 spline hub - 27 spline Birfield joint - 30 spline inner axle


This is known as a 27 spline axle.


Aftermarket Birfields come in 2 spline configurations:

1. 30 spline hub - 27 spline Birfield joint - 30 spline inner axle
   
2. 30 spline hub - 30 spline Birfield joint - 30 spline inner axle

The first option is known as a 27 spline axle and the second is known as a 30 spline axle. We differentiate between the two only on the number of splines inside the Birfield joint. There are no factory Toyota 30 spline axles. They are all 27 spline.

30 spline axles are stronger than 27 spline axles. This has to do with the mechanical properties of splines and the fact that shaft diameter increases with spline count. While a factory inner axleshaft decreases in diameter as it enters the Birfield, an aftermarket 30 spline inner maintains a consistent outer diameter. If you buy a 30 spline chromoly axle, it'll be stronger than a 27 spline chromoly axle.

Toyota Birfield Materials - Stock, 4340 Chromoly, and 300M

Aftermarket Birfields come in two materials, stock-like and 4340 chromoly. We're not going to discuss the stock-like replacement Birfields because if you need to replace a Birfield, you should just put in a used stock unit or a chromoly unit. It seems silly to bother buying a new stock -style Birfield when you can upgrade for a similar price.

If you're buying a Birfield and you want chromoly, make sure it actually says "chromoly" somewhere in the description. We've heard of a few people that bought new Birfs who thought they were getting chromoly just because it was an aftermarket Birfield. This is not the case. An aftermarket Birfield that is not made with chromoly is not any stronger than stock.


All upgraded Toyota Birfield axles are all made with 4340 chromoly at a minimum. This means that the Birfield, inner axle, and inner bearing assembly are all made of chromoly. For most of us, this is strong enough.

One really important idea to keep in mind is that by strengthening one part, we are moving the failure point to a new location. Yes, the old failure point is stronger, but eventually we may move the failure point to a location that's more difficult to repair on the trail. Think about that idea during the next couple of paragraphs.


The next level in strength is to use 300M. 300M is stronger than chromoly. Now you might think that there would be 300M Birfields, but there aren't. Chromo Birfields seem to hold up pretty well, but the inner race and the inner axle become the next failure points. Both of these can be made of 300M.

Beyond these materials, you're looking at swapping in 1 tons! Once you've swapped in a chromo Birfield with a 300M inner race and inner axle, you'll start destroying the splines at the carrier. This is way more difficult to swap on the trail than a Birfield or an inner. Perhaps this is why we see the occasional Dana 60 center with Toy outers?


So, to recap, 300M is stronger than 4340 chromoly which is stronger than stock axle material.

Axle Heat Treatment

There isn't much to say about this except that more heat treatment is better than less heat treatment. Some aftermarket axles have a single heat treatment and some have a double heat treatment.

The Strongest Birfield Axle

The strongest and best Birfield you could buy would be a 30 spline axle with a 4340 chromoly Birfield, a 300M inner race, and a 300M inner axle. There is currently only one kit with these characteristics made by RCV.

Toyota Land Cruiser FJ60 and FJ62 Chromoly Birfield Axles

Below are all of the current axle sets we know of for 60 Series Cruisers. They range from plain, budget-oriented axles to axles with 300M or additional components like hub gears and drive flanges. Something for everyone!


Trail-Gear FJ60 Longfield 30 Spline Birfield/Axle Kit - BUDGET FRIENDLY CHROMOS



Trail-Gear Longfield FJ60 30 Spline Axle Kit Specs

Hub splines	30
Inner bearing splines	30
Differential splines	30
Birfield material (outer axle)	4340 chromoly
Inner race material	4340 chromoly
Inner axle material	4340 chromoly
Birfield length (outer axle)	9.60"
Left inner axle length	31.44"
Right inner axle length	17.13"
Greasable	No
Gun-drilled Birfield	No
Heat treatment	Single

Trail-Gear Longfield FJ60 30 Spline Axle Kit Contents

Birfield (outer axle)	2
Inner axle	2
Inner axle outer C-clip	2
Inner axle seal
Hub gears
Drive flanges

These Longfields are probably the most budget-friendly of all the kits listed here. The axles are simple chromoly with no bells and whistles. They have a single heat treat, unlike the stronger Longfield Super Set axle which has a dual heat treat. In any case, Trail Gear says they are 76% stronger than stock and are a great axle for weekend trail rides or daily drivers that don't see severe off road duty.


Check price on 4 Wheel Parts

Trail-Gear FJ60 Longfield 30 Spline Birfield/Axle Super Set - DUAL HEAT TREAT PLUS CHROMOLY HUB GEARS AND DRIVE FLANGES



Trail-Gear Longfield FJ60 30 Spline Super Set Specs

Hub splines	30
Inner bearing splines	30
Differential splines	30
Birfield material (outer axle)	4340 chromoly
Inner race material	4340 chromoly
Inner axle material	4340 chromoly
Birfield length (outer axle)	9.60"
Left inner axle length	31.44"
Right inner axle length	17.13"
Greasable	Yes
Gun-drilled Birfield	Yes
Heat treatment	Dual

Trail-Gear Longfield FJ60 30 Spline Super Set Contents

Birfield (outer axle)	2
Inner axle	2
Inner axle outer C-clip	2
Inner axle seal
Hub gears	2
Drive flanges	2

According to Trail-Gear the Longfield Super Set is 102% stronger than stock! This is a full chromoly axle set and these are the only axles in this list with a double heat treat. These axles are gun-drilled and fitted with an M8 zerk to make them easier to grease. After pulling off the hub or drive flange, you can pump 5-6 times with your grease gun and you'll have a lubed Birfield. This makes maintenance super easy. Since the next weakest link in your front end is your hub gears, Trail-Gear includes a set of chromoly hub gears.

A set of chromoly drive flanges is also included, but these are only for full time trail rigs. We'd sell these on if you put the Super Set on your daily driver.


Check price on Amazon

RCV Ultimate 30 Spline Axle Set for Toyota Land Cruiser 60 Series - 300M INNER RACE



RCV 30 Spline Axle Set for 60 Series Specs

Hub splines	30
Inner bearing splines	30
Differential splines	30
Birfield material (outer axle)	4340 chromoly
Inner race material	300M
Inner axle material	4340 chromoly
Birfield length (outer axle)	9.60"
Left inner axle length	31.31"
Right inner axle length	17.13"
Greasable	Yes
Gun-drilled Birfield	Yes
Heat treatment

RCV 30 Spline Axle Set for 60 Series Contents

Birfield (outer axle)	2
Inner axle	2
Inner axle outer C-clip	2
Inner axle seal
Hub gears
Drive flanges

RCV says their axles are twice as strong as stock. In addition to 30 spline construction the inner race is also machined out of 300M. RCV is the only manufacturer that makes uses 300M in their Toyota axles. These axles are easily greasable through the gun-drilled Birfields to make maintenance easy.

RCV also often includes free chromoly hub gears with your axle purchase.


Check price on RCV Performance Products

RCV Ultimate 30 Spline Axle Set with 300M Inner Axle for Toyota Land Cruiser 60 Series - STRONGEST



RCV 30 Splines w/ 300M Inner Axle for 60s Kit Specs

Hub splines	30
Inner bearing splines	30
Differential splines	30
Birfield material (outer axle)	4340 chromoly
Inner race material	300M
Inner axle material	300M
Birfield length (outer axle)	9.60"
Left inner axle length	31.31"
Right inner axle length	17.13"
Greasable	Yes
Gun-drilled Birfield	Yes
Heat treatment

RCV 30 Splines w/ 300M Inner Axle for 60s Kit Contents

Birfield (outer axle)	2
Inner axle	2
Inner axle outer C-clip	2
Inner axle seal
Hub gears
Drive flanges

These are likely the strongest axles you can put in your FJ60 or FJ62. Like the previous RCV set, the inner races are machined from 300M. But the inner axle is also machined from 300M. This eliminates the two largest failure points after the Birfield. With the 30 spline construction and the 300M inner race and inner axle, these are strong axles!


Be careful about moving your failure point to your carrier! If your inner can't break, it might be your carrier splines next.


Be on the lookout for the free chromoly hub gears that RVC often includes with their axles.


Check price on RCV Performance Products

Nitro Gear Toyota FJ60 9.5” 30 Spline Chromoly Birfield Front Axle Upgrade Kit



Nitro Gear FJ60 30 Spline Chromoly Birfield Kit Specs

Hub splines	30
Inner bearing splines	30
Differential splines	30
Birfield material (outer axle)	4340 chromoly
Inner race material	4340 chromoly
Inner axle material	4340 chromoly
Birfield length (outer axle)	9.60"
Left inner axle length
Right inner axle length
Greasable	No
Gun-drilled Birfield	No
Heat treatment	Single

Nitro Gear FJ60 30 Spline Chromoly Birfield Kit Contents

Birfield (outer axle)	2
Inner axle	2
Inner axle outer C-clip	2
Inner axle seal
Hub gears
Drive flanges

These 30 spline shafts from Nitro Gear are full 4340 chromoly.


Check price on Amazon

G2 Toyota FJ60 Land Cruiser Birfield CV Style 27/30 Spline Chromoly Axle Kit



G2 Toyota FJ60 27/30 Spline Axle Kit Specs

Hub splines	30
Inner bearing splines	27 or 30
Differential splines	30
Birfield material (outer axle)	4340 chromoly
Inner race material	4340 chromoly
Inner axle material	4340 chromoly
Birfield length (outer axle)	9.60"
Left inner axle length	31.50"
Right inner axle length	17.31"
Greasable	No
Gun-drilled Birfield	No
Heat treatment	Single

G2 Toyota FJ60 27/30 Spline Axle Kit Contents

Birfield (outer axle)	2
Inner axle	2
Inner axle outer C-clip	2
Inner axle seal
Hub gears
Drive flanges

These axleshafts from G2 are full 4340 chromoly. They are available in 27 spline or 30 spline. The 27 spline shafts neck down before entering the Birfield like the stock inner axleshafts. While they're stronger than stock since they're chromoly, we'd stick with the 30 splines.


Check price on Amazon

Marlin Crawler FJ60 30 Spline Chromoly Axle Kit



Marlin Crawler FJ60 30 Spline Chromoly Axle Kit Specs

Hub splines	30
Inner bearing splines	30
Differential splines	30
Birfield material (outer axle)	4340 chromoly
Inner race material	4340 chromoly
Inner axle material	4340 chromoly
Birfield length (outer axle)	9.60"
Left inner axle length
Right inner axle length
Greasable	No
Gun-drilled Birfield	No
Heat treatment	Single

Marlin Crawler FJ60 30 Spline Chromoly Axle Kit Contents

Birfield (outer axle)	2
Inner axle	2
Inner axle outer C-clip	2
Inner axle seal	2
Hub gears
Drive flanges

These 30 spline shafts from Marlin Crawler are full 4340 chromoly. They're manufactured for Marlin by EMPI, a Volkswagen parts wholesaler.


Check price on Marlin Crawler