I have a 1996 LS 400 and want to get an opinion/explanation on changing my front struts and strut mounts according to an invoice from my mechanic. On the invoice my mechanic printed out he has gas charged struts listed for replacement as they are completely worn out on the front. Plus my rack and steering pinion system needs replacement but for another post. Is there a difference between gas charged struts and just regular struts? If this question is making you laugh (i assume struts are operated on some type of gas cylinder), I am newbie so laugh and educate me I am going to fix them soon but my brother has now raised my curiosity with coil overs. Things I would like to know: What exactly is the difference between coil overs and gas charged struts? Strut mounting and struts all came to a grand, pocket-tingling total of $985. So my brother suggested the coil over kit and how much would that go for as for you all that might have converted.

Mileage: 312,000 respectively on the car except the engine and transmission which was replaced around 290,000 miles. (engine, 60,000 and transmission: 110,000 rebuilt)

 

To start, gas-charged strut is just the long form name for strut. All struts are filled with fluid to achieve the damping affect. The gas is what makes them work and prevents the car from bouncing on the suspension springs uncontrollably. No doubt you have seen the occasional car on the road that looks like it is riding on pogo sticks? That is because the struts have worn out seals and the gas has leaked out, rendering the strut useless.

If you just replace the struts with original Lexus replacements, you will retain the original Lexus springs that are currently installed along with your bad struts. Keeping the springs is completely fine, as metal coil springs don't "wear out", unless they are visibly cracked and/or broken. This is what your mechanic is recommending, and this will help restore the amazingly smooth ride that the LS400 is known for.

Now, a gas-charged strut is also a component of a coilover. Coilover is short form for 'coil-over-strut'; with a coilover system the strut and the spring are a package deal, so if you convert to a coilover you will not only be replacing the old Lexus struts but also the Lexus springs. Coilovers are also typically manually adjustable in two ways: 1) vehicle ride height, and 2) damping/rebound stiffness.

In other words, with coilovers you can raise or lower the vehicle to your preference, and control how responsive the strut is to keeping the springs from the bouncing that we mentioned. In other other words, coilovers are for automotive enthusiasts who want to modify the appearance of their vehicles and change handling characteristics.

It is commonly known/accepted that coilovers provide a less comfortable ride quality, partly due to their dedicated purpose, and partly due to the fact the no aftermarket company is as good as making a smooth suspension as the original equipment engineers. This varies widely between brand and model of coilover, but no coilover system will EVER ride as nice as the original Lexus strut and spring setup...

If you aren't big into the car modifying world / scene / lifestyle / whatever, I would highly recommend sticking with just replacing the struts with Lexus equipment instead of going the aftermarket coilover route. Coilovers are a commitment and certainly not for the typical daily commuter.

 

Wow thanks a lot Ethan. That helped me understand a whole lot more. I always thought that the springs was the only component of a suspension system that wasimportant. Didn't know they can last so long. I am some what of a car enthusiast but i would not call myself dedicated. I do like to work on cars/do my own jobs depending on the work and time. I do LOVE the look of lowered cars but i am a student, work full-time and always out and about. So this is pretty much my everything car and would go with the dependability route. Plus the cost for the conversion kit, i am sure, is more expensive than to just change the struts in the front. Now, when i change the struts in front, is it one of those things where it is a good idea to change the rear ones as well? My mechanic said they were in good condition but i would hate to change the front struts and mounts just to have the rear ones go out (hopefully not) a few months or a year after I change the front. How would i test the life of the rear ones if possible?

 

Yes, good practice to change all the shocks at the same time.

KYB made the original shocks for Toyota/Lexus, their GR2 shocks are the most popular aftermarket shock choice for the LS400.