Home Technical Feature Suspension upgrade…

Suspension upgrade…

by admin

Upgrading your suspension doesn’t have to involve massive lifts, especially if it’s your daily driver and has a roof rack on board.

The boss has been on at me for ages (no, not that boss, I mean Kurt the Publisher) about things sagging a bit. I keep telling him about office boundaries, but apparently he meant the suspension on the ADVSUV Prado. He’s done about 110,000km in the last three years over a variety of roads from outback corrugations to speed humps on the school run. He’s even been towing a bit. So I’d say the springs and shocks have taken a bit of a hammering. That’s an easy fix I told him, we’ll just get an uprated suspension kit fitted, then you’ll be sweet.

After a bit of a yarn about what he wanted, I was keen to pass the buck (I mean refer him to the experts). So I picked up the phone and rang my good mates over at Tough Dog Suspension to fill them in on his requirements. It wasn’t long before the guys had come up with the perfect solution and a time was booked in for us to head over to their offices in Western Sydney.


Like many of us, the Publisher’s requirements were fairly varied and there were some absolute deal breakers. We needed to improve the ride, but he didn’t want to increase the height, as with a roof rack on already, it was getting close going into car parks. So we really couldn’t lift it.

First things first though. After giving the Prado the quick once over, the next thing the boys at Tough Dog did was to measure the existing ride height to see how much it had dropped over time. The Prado currently has an alloy bar on the front as well as ARB LED driving lights as well.

All up this has probably added over 50kg to the front of the Prado. Which on a 2-tonne plus vehicle doesn’t sound a lot, but over time it will increase wear on the front springs.

After the measurements were taken the results were pretty clear. The front had sagged by about 15-20mm over standard and rear had dropped about 10mm as well. Although this sounds a lot, to be honest with the amount of kilometres he’s done, the accessories fitted and the type of driving he does it was roughly where we’d expected it to be.


Before the new suspension was fitted we spoke with Simon and Dave again to confirm the type of driving we were likely to do and also Kurt’s requirements. One of the advantages of dealing with a company such as Tough Dog is not only their knowledge through extensive R and D but also the amount of stock they keep on hand. There’s nearly always going to be a solution for your SUV right off the shelf.


The Prado was put on the hoist and lifted. Then the front wheels were removed, which gave Pete (our installer) chance to check the components which weren’t getting replaced for any wear and tear. Good news was everything was fine.

After loosening the strut assembly, the upper ball joint and sway bar were also loosened to enable easy removal. The process was repeated on the other side and the struts were taken to the assembly room for stripping down. After removing the top caps, the old parts were laid down next to the new assemblies. The new strut is significantly thicker with a double wall to protect it against damage and also foam filled for better heat dispersion and performance. Overall, the new springs looked to be about 20mm longer than the originals, which is probably a good indication to the amount the originals had sagged.

In this instance we are re-using the strut cap as the original is still in good condition. Some models tend to wear theirs out quicker than others. If in doubt, always change it. The new spring was compressed, and the strut inserted with the cap tightened up, before being released.

With the struts assembled it was time to re-fit them. This was the reverse of removal with the exception of the lower mount which needs tightening with the Prado back on the floor.

Due to the solid rear axle and rear suspension design, the rear of the Prado is pretty straight forward in comparison. First things first though we need to support the diff – pumpkin on a jack. With the car in the air the shocks are removed and the sway bar is disconnected. Now this next step requires some brute force and usually help from someone else. We need to drop the axle down on one side in order to remove the spring. With the first one out of the way, the second came out easily.

With the new springs in place it was just a matter of re-attaching the new shocks. The decision was made to use non-adjustable rear shocks on the Prado as Kurt does very little towing and doesn’t carry huge amounts of weight in the back of the SUV, so in the end we fitted a pair of Tough Dog Ralph’s (45mm bore) shocks to it.


Once the Prado was back on terra firma, Pete checked all the bolts and made sure everything was tight, remembering the lower bolts on the front struts (apparently, it wasn’t his first install – so we didn’t have to remind him). The Prado was then wheeled out and taken for a quick test run, before measurements were taken.

So did it go up? Well, a little bit, about 20mm all round. This was about what was expected. I’d say the front has gone back up to factory height +/-5mm and the rear is sitting about 10mm higher. Pretty much exactly what the boss had ordered. We did notice a slight pull to one side just after the kit had been fitted, but were advised to check the alignment in 200-500km to make sure everything has settled correctly. After a few days of driving the SUV seems to have settled well and no longer pulls to one side when driving. We are due to get a new set of tyres soon so will get an alignment carried out then anyway, providing the pulling doesn’t return.


From the passenger seat the Prado felt a lot firmer on the drive back to SUVHQ. But passenger seat feedback can be misleading, so I asked Kurt what he thought of it. The smile on his face said it all. “It rides so much better now. Cornering is less wallowy and more controlled. It feels like a new car. It even seems to stop a lot better, due to less pitch when the brakes are applied.”

“Off road, the ride, although stiffer, is more controlled and the Prado hasn’t suffered from that bouncy feeling when the shocks go a little soft from over work. Overall the swap has been a success.”

And yes before you ask, the Prado will still fit into the local multi-story carpark.

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