TRD OR springs

Are the coil springs in the TRD OR suspension (The red Bilstein shocks, not the Fox Trd Pro) different than coils on a regular 4x4?

If they aren’t, does the red Bilstein coilover set up provide any lift over the regular coilsovers?

 

Neither setup are coil overs. All stock suspension is struts. Not entirely sure if the TRD Off-road spring rates in the struts are identical to non-offroad on the springs, but I know there is no difference in ride height between TRD Off-Road and non Off-Road.

 

That's not quite correct. Struts locate the knuckle; the front of the tundra indeed has coilovers - coils over shock - and do nothing to locate the knuckle or a-arms. They simply supply spring and damping between the frame and A arm. The rear is simply a coil and shock separate.

To the original question, I believe the TRD OR springs are variable rate whereas the base non-TRD 4x4 are straight rate coil. I don't recall exactly where that info is posted, but if you look at the coil springs and see an equal gap between each coil, they are straight rate; if you see a tighter gap between a few coils and then a slightly larger gap between the rest, they are a variable rate coil.

 

I'm probably a dumbass.. had that mixed up...always thought coil over meant adjustable...
https://www.shocksurplus.com/blogs/shocks-101/shocks-vs-struts-vs-coilovers
https://performance.bilstein.com/en...n (also called,thread on the suspension strut.

 

Adjustable coilovers are adjustable; but coilovers need not be adjustable to be coilovers except for purebred enthusiasts. Hah. Coilover literally means coil-over-shock. Older vehicle designs utilized a spring and shock separate from each other, and not always a coil spring. Combining the two in to one unit not only saved on space but allowed the spring and shock absorber to travel in sync for better ride control and more predictable handling. They work independently of the axle/wheel locating parts of a suspension such as A arms, pan hard bars, parallel bars, links, etc. and only control movement but don't dictate it.

Struts were originally designed by a guy named McPherson and were and integral part to the suspension geometry. See the graphic below - particularly the two bolts fixing the strut to the steering knuckle. Struts take the place of some the axle/wheel locating parts and both locate the wheel and control movement. In effectively becomes the upper control arm.

If you remove the strut, the wheel is no longer held in place in space and it will flop around, usually laying down sideways. If the strut brakes while you are driving, it is catastrophic and you usually lose the entire wheel and hub and knuckle and brake. If you remove a coil over, by contrast, and replace with say, a 2x4 or hockey puck, the wheel is still held in place by the other suspension components and you could drive, steer, etc. If your coilover were to brake while driving, you would simply bottom out the suspension but retain the ability to steer and stop the vehicle.

Not trying to be a jerk or anything, so don't take it the wrong way. Just trying to provide accurate info.

 

I know you're not trying to be a jerk, I'm not either. What fun is the the internet without people to disagree with???

Technically a Macpherson Sturt is a Coil over too because well the coil is over the shock. @blenton looks like most companies are just using the wrong terminology then...

 

Haha. No joke! I was just cruising through some 3rd gen discussion and shaking my head, think, wow - I really don't want to turn this thread in to piss and vinegar. Perhaps we should talk clips and magazines...?

IME, most car guys will use the term interchangeably. I had a performance shop guy get after me for calling struts coilovers and coilover struts one time. He's a buddy so it was in jest, but he builds race cars and grew up in a family owned and operated shop so I deferred to his expertise. I know I'm plenty ignorant on my own

 

To me it seems like most companies in the suspension industry only bring "coil overs" into the name equation when they are adjustable and anytime a shock and spring are one unit they are struts no matter what your buddy has said that seems to me to be pretty industry standard to call a spring and shock assembly a strut. When its a Macpherson strut you call it so and when the shock and spring are assembled they are struts and sometimes they are a Macpherson strut. The word Macpherson wouldn't' be needed if you could just say strut.

 

Thank you!

 

Right. What industry does and what industry should do are two separate things. "Made In America" shouldn't come with an asterisk, but unfortunately it does.

The distinction between a strut and coilover as explained to me was whether or not it located the wheel or played a part in suspension geometry (other than ride height). Struts locate and dictate geometry, coilovers do not.

The McPherson strut was the original and others have modified to their needs. It simplified car suspensions and made them cheaper to build. Though it has a coil over a shock absorber body, that shock absorber is integrated in to the geometry components rather than being an independent entity, if that makes sense. As noted above, you can remove the coilover assembly entirely from a vehicle and the suspension geometry would remain the same and functional. That's really the gist of of it - again, as it was explained to me.

 

If you remove the shock and spring (which I'm referring to as a strut here), the wheel would push all the way into the fender when the vehicle is set down, potentially putting a lot of stress on the CV axles or even breaking a CV or ball joint. In a double wishbone suspension, the strut helps align the upper and lower control arm ball joints with the wheel hub and ensures proper CV alignment. If the geometry stays the same, you wouldn’t need an alignment after a lift. At the very least, you need a shock in place; I learned this when young and dumb when I helped remove the springs from a car to lower it because with no springs your stance was sick.... Without a shock, the wheel can easily blow through the fender and damage the CV axle.

Without a strut the upper and lower control arms won't really function.....off to go yell in the wind...