Hilux inverted leaf springs

Hi my Hilux leaf springs are inverted & it's affecting the towing off big trailers to be fair it towing like shit now use to tow really well & are towing the same trailer with the same load.I have got a 3 year old Hilux it's done 90 thousand km the springs are factory the Ute is a double cab well side with a canopy on I'm thinking I need to upgrade the springs but don't know what to go to I don't want to give it a 2 inch lift I'm happy with factory height whatever I put in needs to be able to ride good when empty as I don't carry big weights in the canopy very often but do a lot off towing weight off trailer & load would be round 2-2.5 ton. So my question is what would you put in the back so it rides good empty but can handle the weight off a big trailer thanks

Factory rear springs but add another factory main leaf with the eyes cut off, taper the cut to avoid concentrating load stress at the cut

The D bolts are long enough, just make another centre bolt and trim to length

Adds a large amount of load capability and rear stability

Do a bit of math on it, work out what your standard weight on the rear spring pack is and then divide by about 75 (Kg, which is about what each leaf will carry). I went from the standard 3-leaf plus overload plate to a 7-leaf plus overload on the ranger. Fixed the junk springs it shipped with and the bs ride they gave, now much more acceptable although I would not like to be in it fully empty.

I have a wellside, liner tub, 75Kg of canopy and 65Kg of ute drawer in it permanently plus probably 45Kg of tools?

Plan to upgrade the shocks at the rear and you will need to adjust the front to correct the ride height and sort the alignment most likely. With more leaves in the rear spring pack you will gain lift which will also drop the nose and this is not good for alignment. I set the new foam cell front struts up with the factory coils but with a 10mm spacer to increase the preload which gave me 20mm lift at the front which pulled everything back into correct alignment. So far no issues with driveline angles, 136,000Km and the front lower ball joints need replacing it's the only wear item so far.

I'll add to that, for 2500Kg trailer that should be 250Kg of downforce on the towball which is all back end no load sharing to the front. With a canopy of say 65Kg for a plastic type your towing load increases over empty by 315Kg - I would think that a leaf pack designed for medium load carry or 50% of max rear axle load might work? Probably a 5 or 6 leaf pack depending on who supplies it. Or maybe the modified leaf mentioned above plus one standard mid pack leaf on each side, will need new u bolts and center bolt though you won't squeeze two more leafs in with the factory bolts.

Go to a decent spring / suspension shop.and ask for some advice. I did this with my navara and it tows way better. But these have coil spring rear end . I'm sure there will.be a heavy duty spring set that can be offered. It's no different than any industry .the best advice is professional advice. It's a good starting point you can always decide upon what to do on your budget. I wonder why they flip the leafs..we use to do this in our cars back in the day to lower them.lol

Air bags. I adjust my load regularly

I've used airbags a couple of times on work vehicles, they can be a pain in the arse if for some reason one side ends up at a different pressure to the other. They do seem to improve the ride but to my thinking it's just another thing to have to do. If you are towing all the time but then for some reason not towing and deflate the bags for ride comfort and get a surprise tow job come up you have to pump up the bags. That means carting a damn compressor or pump with ya, just more crap!

My thoughts are just sort the suspension out right first time, get it set up for the loads you normally work with and the vehicle will go better for it. The chassis for one will be happier without smashing the bump stops all the time, and for some vehicles even things like airbags can stress the chassis where it's not reinforced for it.

Just keep in mind that adding cut down springs to spring packs, and airbags, all require cert.

A replacement spring pack perhaps? They're not expensive

https://motortech4x4.co.nz/product/o...hilux-2015-on/

In 1996 we were running a fleet of Jeep Cherokees XJ's in Cambodia with the UN. Some donor coughed up for 50 new Hiluxes and when they all turned up the (Cambodian) Service manager had a fit, as all of the front suspension had inverted leaf suspension. All he was used to was the XJ's conventional rear suspension packs, so he thought they were all rooted from new, and someone had done the dirty on him. Took a few photos of what a new Hilux looked like in Japan and America for him to calm down:D

By the way, we had an AWFUL lot of fun thrashing the snot out of those XJ's out on an old dirt airstrip in Campong Chhnang before sending them back to the knackers yard. Reverse J turns, evasive manouevers etc etc. Oddly enough none even tried to overturn. Bloody good wagons those.

Quote:

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Originally Posted by Tommy

Just keep in mind that adding cut down springs to spring packs, and airbags, all require cert.

A replacement spring pack perhaps? They're not expensive

https://motortech4x4.co.nz/product/o...hilux-2015-on/

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Huh, didn't know that airbags require a cert. Also didn't know that a cut down leaf required a cert as well... I'm amazed if they are getting that strict that you can replace the leaf pack with an aftermarket and not need a cert!

But yeah, those leaf packs look about right from where my experience of these things go - they aren't that dear as indicated. But add to that price doing the rear shocks as the factory gas struts just won't handle those springs at all, the biggest single change you can make is replacing the shocks and even just doing the shocks will make a hell of a difference to how the factory springs behave.

I think that the main issue with the factory shocks is that they are designed and calibrated for the vehicle unloaded and they do that well, expect that we in NZ suddenly hang towbars on the back and expect the vehicle to suddenly do the work it's designed to do empty but at full axle loads. Something has to give, and in this case the gas-oil factory shocks suddenly find their operating cycles go up a huge amount and the result is heat. Heat is the enemy of shock oil, the viscosity lowers as the oil heats up and it passes through the shocks valving much more quickly and reduces the damping effect. This in turn means that the springs start getting smacked in to next week with no damping, and this is how the springs end up going past their elastic limit.

The next problem is the suspension at both ends must work together to keep everything pointing the same way - if you upgrade the back end the front will feel like absolute garbage. As a minimum get the matching set of front struts to the back, and retain the factory springs. You may require a spacer on the spring to increase the preload slightly - my understanding of the rules is that provided you don't increase the lift past 50mm and don't have anything adjustable without disassembly you are able to do this without cert. For reference, most of the ute double wishbone front ends run a 2-1 design ratio which roughly means a 10mm spacer increasing the preload on the factory spring gives about a 20mm lift at the wheel. You won't notice the effect of the spacer on travel or articulation in normal conditions.

Quote:

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Originally Posted by Quackers

Go to a decent spring / suspension shop.and ask for some advice. I did this with my navara and it tows way better. But these have coil spring rear end . I'm sure there will.be a heavy duty spring set that can be offered. It's no different than any industry .the best advice is professional advice. It's a good starting point you can always decide upon what to do on your budget. I wonder why they flip the leafs..we use to do this in our cars back in the day to lower them.lol

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I have been to 3 tyre shops & Toyota (witch I have tried twice & they haven't bothered to come back to me with anything) in town and the only 1 has come back to me & they are saying just to replace the rear springs and putting lot bigger shocks in and priced around $2000 we don't have any specialised suspension shops in the town that i live in

I'm not putting airbags in I know off other Utes with them & they all hate them & wished they had saved there $1000 & are getting sick off taken them out for wof because they haven't cert them lol

Who makes the best springs is it is it best to go out off town to the likes off arb I have never change the springs or shocks in a vehicle before so that's why I'm asking on here as with only 1 shop coming back to me I'm not getting much advice sure i could chasse them up but I'm more like if they want my $ they will do what they say they will & if they don't I'll go elsewhere lol

@hunt08

Mate, this is not a difficult problem to solve.

Get in touch with one of the suspension specialists in Hamilton. I recommend Automotive Solutions Hamilton. They carry Lovells springs which is a superior brand used throughout Australia for commercial vehicles, not a flash Harry 4WD product but a proper working vehicle product. Tell them what you need, they will tailor the right package, you drive up from Wanganui early on the day, drive home later that afternoon in what will feel like a completely different vehicle.
@MSL is someone to ask, pretty sure he used these guys in Hamilton as well. Maybe someone else. Either way he was very happy with his Hilux suspension upgrade, also for loads & work use.

Like I say, not hard, it’s gonna cost you but it will it will transform your Hilux and last forever.

Ring auto lighn mt wellington In auckland and talk to Ian.

Quote:

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Originally Posted by Flyblown

@hunt08

Mate, this is not a difficult problem to solve.

Get in touch with one of the suspension specialists in Hamilton. I recommend Automotive Solutions Hamilton. They carry Lovells springs which is a superior brand used throughout Australia for commercial vehicles, not a flash Harry 4WD product but a proper working vehicle product. Tell them what you need, they will tailor the right package, you drive up from Wanganui early on the day, drive home later that afternoon in what will feel like a completely different vehicle.
@MSL is someone to ask, pretty sure he used these guys in Hamilton as well. Maybe someone else. Either way he was very happy with his Hilux suspension upgrade, also for loads & work use.

Like I say, not hard, it’s gonna cost you but it will it will transform your Hilux and last forever.

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Thanks for that I know it's not hard thing to solve but it's finding the right people to do the job that know what the talking about is the hard thing when I don't know enough about it to know when sales people are talking shit to make a sale lol

I will make some phone calls when I get a chance next week

Quote:

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Originally Posted by Flyblown

@hunt08

Mate, this is not a difficult problem to solve.

Get in touch with one of the suspension specialists in Hamilton. I recommend Automotive Solutions Hamilton. They carry Lovells springs which is a superior brand used throughout Australia for commercial vehicles, not a flash Harry 4WD product but a proper working vehicle product. Tell them what you need, they will tailor the right package, you drive up from Wanganui early on the day, drive home later that afternoon in what will feel like a completely different vehicle.
@MSL is someone to ask, pretty sure he used these guys in Hamilton as well. Maybe someone else. Either way he was very happy with his Hilux suspension upgrade, also for loads & work use.

Like I say, not hard, it’s gonna cost you but it will it will transform your Hilux and last forever.

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Yep, good advice. I found exactly what you did, about 3 shops/dealers including Ford's local walked away and couldn't sort it after the uprated rear leafs were installed (they were done leaving the factory shocks at the back and front untouched due to smashing towball shanks on driveways and not being able to connect trailers up as the jockey wheel would not wind down enough to unweight the trailer coupling). This is why I'm saying you need to do the front at the same time, what happened to mine is the rear lift through fitting the 7-leaf pack took the front end past the limits of the alignment devices and effectively turned the vehicle into a widowmaker - the front end would just depart control with zero warning and slide to one side or the other. On gravel, ended up needing to operate it like a rally car - in 4wd and the boot hard up the boitch to pull the front end straight. Total pain in the arse...

Ford left the chat at this point, so I had to find someone to fix it which is when I found out I couldn't as basically there wasn't anyone with the knowledge on the PX ranger at that stage. Imported a set of foam cell shocks and struts and front springs - fitted them which meant it went a lot better but the front end on heavy springs without a bar or winch meant there wasn't enough weight over the front axle so it drove like a forklift. Cornered amazing though haha.

Took the aftermarket coils out, and put the standard back in - luckily I had dimensioned everything prior to doing the mods so a bit of a run with the calculator and a few well aimed guesstimates was how I ended up with a 10mm spacer on the front strut to slightly increase the front end preload. Next problem is the spacers were not available in NZ and on 3 month backorder in Aus, so I had to bloody make them! Another pain in the arse. All done, it was a massive improvement in ride quality, compliance when hitting bumps etc and also road manners - the interesting one is the traction control was a lot more gentle and smoother when engaging rather than the crash when it was on factory gear.

As @Flyblown said, I had automotive solutions fit some EFS uprated leaf packs and KYB scortched earth shocks to the rear of my 2014 hilux. My Old man emu uprated leaf packs had done the sad face bend.


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Huh, didn't know that airbags require a cert. Also didn't know that a cut down leaf required a cert as well...
I'm amazed if they are getting that strict that you can replace the leaf pack with an aftermarket and not need a cert!
--https://vehicleinspection.nzta.govt.nz/virms/in-service-wof-and-cof/general/steering-and-suspension/steering-and-suspension-systems
the springs or shock absorbers are direct replacements, and
replacement springs are contained within unmodified OE seats throughout full suspension travel (Note 8), and
replacement springs are self-retaining in their seats at full extension, without the use of non-standard devices such as wire-ties, straps, or external spring locators, and
replacement springs have not been heated or cut, and
springs and spring seats are not height adjustable by any means (unless OE) (Note 9), and
replacement shock absorbers, including air-adjustable units, fit unmodified OE mountings (Note 8), and
suspension maintains sufficient travel for safe operation (Note 10), and
suspension components maintain sufficient clearance from unmodified bump stops when fully laden (Note 11), and
Suspension retains at least 40mm of rebound (droop) wheel travel (Note 12), and
a minimum of 100mm ground clearance (unladen and without driver) exists below any part of the vehicle structure, or any steering, braking or suspension component (Note 13) and
the normal relationship between front and rear suspension height is not unduly affected, and
clearance is maintained between all components, when tested from lock to lock at full droop

But yeah, those leaf packs look about right from where my experience of these things go - they aren't that dear as indicated. But add to that price doing the rear shocks as the factory gas struts just won't handle those springs at all, the biggest single change you can make is replacing the shocks and even just doing the shocks will make a hell of a difference to how the factory springs behave.
Yup, you'd chuck some decent shocks at it too
I think that the main issue with the factory shocks is that they are designed and calibrated for the vehicle unloaded and they do that well, expect that we in NZ suddenly hang towbars on the back and expect the vehicle to suddenly do the work it's designed to do empty but at full axle loads. Something has to give, and in this case the gas-oil factory shocks suddenly find their operating cycles go up a huge amount and the result is heat. Heat is the enemy of shock oil, the viscosity lowers as the oil heats up and it passes through the shocks valving much more quickly and reduces the damping effect. This in turn means that the springs start getting smacked in to next week with no damping, and this is how the springs end up going past their elastic limit.
Yep

The next problem is the suspension at both ends must work together to keep everything pointing the same way - if you upgrade the back end the front will feel like absolute garbage. As a minimum get the matching set of front struts to the back, and retain the factory springs. You may require a spacer on the spring to increase the preload slightly - my understanding of the rules is that provided you don't increase the lift past 50mm and don't have anything adjustable without disassembly you are able to do this without cert. For reference, most of the ute double wishbone front ends run a 2-1 design ratio which roughly means a 10mm spacer increasing the preload on the factory spring gives about a 20mm lift at the wheel. You won't notice the effect of the spacer on travel or articulation in normal conditions. Again, that's going to require cert - "Note 8- Strut or spring spacers always require certification."

Quote:

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Originally Posted by hunt08

I will make some phone calls when I get a chance next week

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It’ll be all good, just explain what you are using the ute for, ute tray loads and trailer loads, types of roads. They’ll have a pretty standard product for you on the shelf, pretty sure of that. Remove the old, bolt on the new, not a big job, done it heaps of times myself at home with Hiluxs going back to the early 90s. Even did it once on a hill in Malawi. Carried spare spring packs on the front of the vehicle… very handy to stand on.

https://i.vgy.me/WCIL49.jpg

(yes, I know, posted probably a dozen times already)

Similar to the Expedition series Landies operating in Mozambique when I was there. Fully loaded with camping and hunting gear for three weeks. Plus punters on board. Pathetic front diff spider gear shaft, so better carry a spare diff head. Half shafts snap like carrots, so lets carry three spares. Wagon is now looking overloaded, so better carry a couple of spare leaf packs...and so on and so on. :o

Quote:

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Originally Posted by Tommy

Huh, didn't know that airbags require a cert. Also didn't know that a cut down leaf required a cert as well...
I'm amazed if they are getting that strict that you can replace the leaf pack with an aftermarket and not need a cert!
--https://vehicleinspection.nzta.govt.nz/virms/in-service-wof-and-cof/general/steering-and-suspension/steering-and-suspension-systems
the springs or shock absorbers are direct replacements, and
replacement springs are contained within unmodified OE seats throughout full suspension travel (Note 8), and
replacement springs are self-retaining in their seats at full extension, without the use of non-standard devices such as wire-ties, straps, or external spring locators, and
replacement springs have not been heated or cut, and
springs and spring seats are not height adjustable by any means (unless OE) (Note 9), and
replacement shock absorbers, including air-adjustable units, fit unmodified OE mountings (Note 8), and
suspension maintains sufficient travel for safe operation (Note 10), and
suspension components maintain sufficient clearance from unmodified bump stops when fully laden (Note 11), and
Suspension retains at least 40mm of rebound (droop) wheel travel (Note 12), and
a minimum of 100mm ground clearance (unladen and without driver) exists below any part of the vehicle structure, or any steering, braking or suspension component (Note 13) and
the normal relationship between front and rear suspension height is not unduly affected, and
clearance is maintained between all components, when tested from lock to lock at full droop

But yeah, those leaf packs look about right from where my experience of these things go - they aren't that dear as indicated. But add to that price doing the rear shocks as the factory gas struts just won't handle those springs at all, the biggest single change you can make is replacing the shocks and even just doing the shocks will make a hell of a difference to how the factory springs behave.
Yup, you'd chuck some decent shocks at it too
I think that the main issue with the factory shocks is that they are designed and calibrated for the vehicle unloaded and they do that well, expect that we in NZ suddenly hang towbars on the back and expect the vehicle to suddenly do the work it's designed to do empty but at full axle loads. Something has to give, and in this case the gas-oil factory shocks suddenly find their operating cycles go up a huge amount and the result is heat. Heat is the enemy of shock oil, the viscosity lowers as the oil heats up and it passes through the shocks valving much more quickly and reduces the damping effect. This in turn means that the springs start getting smacked in to next week with no damping, and this is how the springs end up going past their elastic limit.
Yep

The next problem is the suspension at both ends must work together to keep everything pointing the same way - if you upgrade the back end the front will feel like absolute garbage. As a minimum get the matching set of front struts to the back, and retain the factory springs. You may require a spacer on the spring to increase the preload slightly - my understanding of the rules is that provided you don't increase the lift past 50mm and don't have anything adjustable without disassembly you are able to do this without cert. For reference, most of the ute double wishbone front ends run a 2-1 design ratio which roughly means a 10mm spacer increasing the preload on the factory spring gives about a 20mm lift at the wheel. You won't notice the effect of the spacer on travel or articulation in normal conditions. Again, that's going to require cert - "Note 8- Strut or spring spacers always require certification."

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Ahhh - that's how those particular ones I got are able to do it then. The lower spring cup is a separate part to the shock body on the foam cell struts I got which is where the spacer goes - between the lower cup and the strut body and cup stop ring. The spring remains fully contained within the designed elements of the strut and factory upper mounting. It's a designed system and non-adjustable once the spring is in place and serves to only control the preload on the coil spring. Probably a better term is a preload adjustment element rather than spacer? It's not a spring spacer or a strut spacer according to that definition. Good to know... Thanks.

On the other hand - how in the hell do ute makers claim that their products meet WOF specs at full load when with half of them the vehicle is sitting ON the bump stops at 500Kg below max rear axle weight? I've often asked this and get the 'mumble mumble mumble' reply.