So McPherson struts are only used in the front suspension, never in the rear?
A strut controls the dynamics of the wheel through its movement. It generally bolts directly and robustly to the steering knuckle in a way that keeps the spindle at the angle the designer intended throughout its vertical movement. A strut will rotate only around the steering axis.
A ācoiloverā does not control the movement of the axle beyond absorbing bumps. It simply combines the spring, which supports the vehicle as well as absorbing shocks, and the shock, which ādampsā oscillations inherent in springs. Itāll rotate freely with respect to the spindle, the spindleās movement being controlled by control arms.
While Iām not a stickler for nomenclature, the āstrutā in the recent post (three posts prior) really is just a coilover shock and not a strut. It does not control the movement of the spindle other than to absorb and dampen impact. I felt it important to point that out I order to be clear regarding the difference.
1 Like
What does part 7 in the diagram above bolt to, top and bottom? The top I presume bolts to the body or chassis, and the bottom bolts to what? The lower control arm ? The steering knuckle?
Bottom hinges at number 4 on the diagram.
Exactly.
It bolts to the lower control arm exactly where the arrow from the number 4 is pointing.
The top bolts to the upper mount in the strut towers.
So is part 7 a strut? Or not a strut? Since it doesnāt bolt to the steering knuckle, Iām presuming it is not a strut, right?
Itās certainly not a McPherson strut.
1 Like
Not a strut.
Simply an air shock.
Used front and rear (look at your Corolla).
1 Like
But no steering knuckle in the rear? I thought it had to bolt to the steering knuckle to be a McPherson strut.
They can be used in the rear. They can be bolted to the hub
However, the 2005 Corolla (and probably other Corolla years of that era) uses a coilover shock, not a strut. Attached is a 2005 Corolla rear end.
I see. So if a rear strut is bolted to the hub it would still be a McPherson strut. Iām pretty sure the rear strut on my early 90ās Corolla is bolted to the hub assembly. So that makes it a rear McPherson strut then?
The 2005 Corolla design the corresponding part appears to be bolted to the axle assāy, right? Not the hub. I wonder why motivated the design change?
Not necessarily.
The thing that makes a strut a strut is not what itās bolted to. The thing that makes it a strut is that it controls the movement of the wheel through its suspension travel rather than simply absorbing bumps and damping oscillations. To do that it needs to be bolted solidly to the hub or steering knuckle, but a shock could also be bolted to the hubā¦ with the wheelās movement controlled by control rams.
Focus not on where the damper is bolted, but rather what it does. What it does is what makes it a strut. Or a shock.
Did you mean to type ācontrol armsā?
On my Corolla it is bolted on the top to the body, sort of in front & even with the trunk lid. On the bottom it is bolted to the hub assāy. But the hub has arms fore and aft that control its movement relative to the body, as well as a bar from one side to the other that controls lateral sway.
LOL, yup. Nice catch.
What year is your Corolla? Iāll post an image of its rear suspension.
- That is, I must say to reach the 10 character limit, 1992
Itās a strut.
The best way to tell is that it shows the āclampā with the two bolts that secures it solidly to the hub, allowing no movement between the strut and the hub. A shock will have only one bolt and a bushing to allow movement of the hub relative to the shock.
2 Likes
Very informative TSM. Thanks for taking time to explain. Yes, that diagram you posted is what it looks like. Now I think about it, rather than dual arms going fore and aft to control the hub geometry, thereās actually two parallel arms going forward from the hub to the chassis, presumably 48710J and 48780A, and part 48730A is actually vertically oriented, and attaches the hub to the sway bar which goes over horizontally to the hub assāy on other side of the car.
Iām not sure why they show 710 J at right angles to 780A. I think those parts are parallel. Thatās a curious thing.
I think 780A is a fore-aft link, and 710J and 730A are the lateral links. Slide under your Corolla and have a look.
;-]
1 Like