JMACX Billet Leaf Spring High Clearance Mounts
In this 4WD build post we look at our JMACX Billet Leaf Spring High Clearance Mounts that we fitted to our 76 (70) Series Toyota Land Cruiser.
Land Cruiser Leaf Spring Clearance Problem
The 70 Series Toyota Land Cruiser range all come out with rear leaf springs, even the 76 Series wagon that we own. All 70 Series owners do not have the luxury and comfort of coil springs all around as Toyota kept leaf springs in the rear due to the payload of the 70 Series Land Cruiser range. Leaf springs are a far better setup when carrying heavy loads in the rear. Therefore, all utes or trucks, if you do not live in Australia, come with rear leaf springs. The one ute that we know of that does come with rear coil springs is the Ford Ranger Raptor and that has a far lower payload and GVM than the 70 Series Land Cruiser. There is always the option pre-registration to drop well over $30k and get a coil spring conversion done if you are lucky enough to have such a big budget.
The leaf springs on the 70 Series Toyota Land Cruiser are bolted to the rear diff with U bolts. These U bolts sit on top of the diff and then run down alongside the leaf spring pack that sit underneath the diff to a large plate. The U bolts are then secured through this plate which provides some protection to these U bolt nuts keeping your springs secured to the rear diff. This plate also secures the bottom of the rear shocks. The issue here is the overall design of this steel plate. Firstly, it loves to attract all sorts of dirt and mud and is a pain to keep clean. Secondly, and most importantly, this steel plate sits extremely low and is the lowest point underneath the 70 Series Toyota Land Cruiser. What this means is that it you will most definitely, at some point in time, snag this plate on a rock or some other obstacle. It is also not just getting snagged on rocks and other obstacles, but just driving through thick sand these leaf spring plates will drag through the sand. We know we have done this numerous times in under 24 months of owning our 76 Series Toyota Land Cruiser. Therefore, they are commonly known by 4WD enthusiasts as “leaf hangers”, they get you hung up on everything basically.
JMACX High Clearance Mounts
Australian Materials & Australian Made
JMACX have designed and manufactured in Australia a replacement part for these “leaf hangers” called their JMACX Billet Leaf Spring High Clearance Mounts. Now we will be honest here, these replacement leaf spring mounts are in the low priority of upgrades needed with a 70 Series Toyota Land Cruiser as well as being super expensive. We will only recommend replacing the stock Toyota leaf spring mounts if you have the budget and are continually scraping them over obstacles. Starting at $750 for a pair plus another $110 if you have airbags for the airbag brackets, they are an expensive upgrade, welcome to the 70 Series money pit. So, they are expensive, but the JMACX Billet Leaf Spring High Clearance Mounts are an exceptionally well made Australian manufactured replacement part, using super strong Australian made raw materials which is the reason for the hefty price tag.
Super Strong & Durable
The JMACX Billet High Clearance Mounts are CNC machined out of Australian made Bisalloy 80 (BIS 80) high strength structural steel. Bisalloy 80 is a high strength, low alloy structure steel that is three times greater than carbon steel. As a result, BIS 80 as a raw material provides the optimum level of strength, durability, hardness, and density over normal steel. As BIS 80 is three times stronger than steel, it allows steel thickness to be reduced while maintaining structural integrity as well as keeping the weight down.
CNC Machined
The JMACX Billet Leaf Spring High Clearance Mounts look like a work of art with their gold coloured SA5 (zinc) coating and perfect finishing due to the clean lines and curves from being CNC machined out of a solid piece of steel. Overall, the JMACX Billet High Clearance Mounts are by far a superior leaf spring mounting solution to the factory Toyota U bolt mounting plates. The high clearance plates come in two separate pieces which are connected by four bolts. The top piece has been machined to follow the curve of the factory diff so that it can sit perfectly on top of the diff. The bottom piece has been machined to allow the leaf spring pack to sit inside of it neatly as well as having a support on the side to mount the bottom of your rear shock absorber. These two pieces are connected by four bolts that are based on the total depth of your leaf spring pack. As we run Airbag Man rear airbags, we had to purchase an additional bracket for the airbags to be mounted to as the standard brackets will not work with these high clearance mounts.
Close to 30MM Improved Clearance
By fitting the JMACX Billet Leaf Spring High Clearance Mounts we were able to increase our lowest point of clearance by almost 30mm, just over one inch, from the stock Toyota leaf spring mounting plates. From the pictures in this post, you can see that the lowest point, the bottom of our shocks, is sitting only slightly lower than the lowest leaf spring. This is a huge improvement in clearance from stock. The other benefit in the design of the JMACX Billet Leaf Spring High Clearance Mounts is from the smooth base of the bottom plate. This means that if we are rolling slowly over rocks and other obstacles and we still snag the bottom of our leaf springs, we should slide over the obstacle rather than get caught up on it as there is nothing to get snagged on. The other benefit of this design is that you do not get mud, dirt and sand stuck in between the bolts as we always did with the stock Toyota leaf spring plates.
Not a Substitute for Larger Tyres
We have seen some commentary on how fitting the JMACX Billet Leaf Spring High Clearance Mounts are like fitting 35-inch tyres compared to 33-inch tyres due to the added clearance of 1 inch with 35’s. In one instance this is true as we have increased our lowest clearance point by close to 30mm, however the clearance of our diff has not changed being one of the main reasons why someone would choose to fit 35-inch tyres (even though they are illegal in Queensland without engineering approval). So, if you have seen similar commentary, fitting JMACX Billet Leaf Spring High Clearance mounts is not like fitting 35-inch tyres as you are only improving the clearance of your leaf spring mounting plates not your diff.
High Clearance Mount Specifications
Here is a summary of the specifications of our JMACX Billet Leaf Spring High Clearance Mounts:
- Only suitable for the 70 Series Toyota Land Cruiser.
- Australian made using Australian materials.
- CNC machined out of Bisalloy 80 high strength structural steel.
- Increased strength over factory Toyota leaf spring mounting plates.
- Improved clearance over factory of approximately 30mm.
- SA5 (zinc) coated for corrosion resistance.
- Increased clamping strength due to design.
- Airbag Man compatible with additional mounting bracket.
- Fit standard Toyota diff housing as well as the JMACX upgraded diff correcting housing.
- Different bolt lengths based on leaf spring pack size from 60MM to 130MM in increments of 5MM.
- Cost $750 for a pair of mounts plus another $110 for the airbag mounting brackets.
- Are not a substitute for larger tyres however they do increase the lowest clearance point.
There Are Other Options
JMACX are not the only company making high clearance leaf spring mounts in Australia, Superior Engineering have two different options at different price points. Superior Engineering have a budget option that is around $200 made from normal steel but is nowhere near as strong highlighted by the fact that they cannot be used with a GVM upgrade. They also have a more premium product for $700 also made from billet steel however these are an inferior design while still using U bolts and not providing as much clearance as the JMACX option (but only slightly). The Superior billet option also requires you to cut the U bolts to size compared to JMACX providing you the correct bolt length based on your leaf pack depth. Also be prepared to wait for several months to receive these products from Superior Engineering as they are usually made to order.
Overall Verdict
As we highlighted above in this post, we would not recommend this upgrade unless you are constantly having issues getting hung up on obstacles due to the poor clearance of the stock Toyota leaf spring mounting plates as they are not a cheap upgrade. If you have the budget, then these JMACX Billet Leaf Spring High Clearance Mounts are an exceptionally well-made Australian product. As they are Australian made using Australian materials you can expect them to be of the highest quality, but they of course will come with the associated price tag. However, you will not be disappointed if you chose to fit these JMACX leaf spring high clearance mounts as they do everything that they advertise. The improvement in clearance in close to 30MM makes a massive difference when driving over rocky terrain and even just through thick sand. The flush smooth finish of the bottom mounting plates lets you slide over obstacles rather than caught up as well as stopping all the mud and dirt from getting stuck up in the mounting plates. If you run airbags, then you will need to purchase the additional mounting brackets, but they are an improvement from the standard ones you receive with them. Overall, the JMACX Billet Leaf Spring High Clearance Mounts are a great looking big of gear and do exactly what they are supposed to. If you drive off road regularly and have the budget then these are a great upgrade from the stock leaf spring mounting plates.
This is not a sponsored post we paid for these and is our honest opinion. If you would like to see the JMACX Billet Leaf Spring High Clearance Mounts on their website click here.
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The thoughts of Peter.
31/08/2022 @ 8:50 PM
Hey guys, just bought some parabolics from terrain tamer for the2021 troopy VDJ78. It’s got the suspension 2inch lift and diff correction done by superior engineering Looking to find a proper high clearance u bolt kit. Can you help me? The coil conversion is out of my reach so just trying to find the next best thing.
Cheers
Tim
01/09/2022 @ 9:36 AM
G’day Tim,
That sounds great mate. I am interested to hear how the parabolics go for you. I hear they are extremely comfortable.
For me personally, if you get the right leaf spring rating to your load, comfort is going to be fine and a coil conversion is not worth the cost. For a touring setup, leaf springs setup correctly are absolutely fine. From the research I have done, you really only have two options for high clearance U bolt kits. Either JMACX or Superior. Superior have two options, one that is cheaper but definitely not as strong and the more expensive option similar to our JMACX high clearance mounts. I decided on JMACX as I preferred the design of their kit, although it is expensive. I like how they provide the correct bolt sizes to match your leaf pack so no cutting required. The more expensive Superior option still uses U bolts which need to be cut down depending on the size of your leaf pack. I am not sure which is a better option but this will really come down to your preference.
To be prefectly honest, the type of trips we do, we really did not need these. If you are doing mainly tough 4WD tracks and clearance is an issue, then they are a good option.
Take a look at the two Superior kits and the JMACX kit, and make a decision based on budget and what you really need. Hope that helps.
Cheers,
Peter