- Joined
- Jan 1, 2012
- Messages
- 8,341
- Reaction score
- 1,183
- Location
- Eugene, OR
- My Car
- 1971 Mustang Sportroof M code
I have been reading about various front suspension upgrades for our cars for quite some time. There have been a lot of pros and cons discussed for several of the options, including heim joint strut rods, urethane strut rod bushings, strut rods with pivot joint (ball joint type) end, urethane lower control arm (LCA)bushings, spherical joints (inner) on LCAs, and pivot joint (inner) LCAs.
I've seen mention of roller bearing (inner) LCAs but haven't found any. There is a good reason for this, as the LCA swings up and down it is forced to rotate along its axis by the strut rod movement. I estimate this rotation to be around 20 degrees. If the LCA cannot rotate at the inner joint the LCA would have to twist or the strut rod would have to flex (bend). The LCA also has some side-to-side movement.
The strut rod also has to swing up and down, side-to-side, and rotate along its axis, which is why it is connected to the frame the way it is.
The new (introduced in 2015) Mustang front suspension gets around this by using what they call a double ball joint connection at the spindle, with the LCA, (lateral link) and the strut rod (tension link) both connected to the spindle with ball joints (see illustrations below). This also allows a more positive connection of the LCA and strut rod to the frame, as they only have to swing up and down and have a little side-to-side movement, but no rotation.
Another big difference is that the new suspension has front steering while ours have rear steering (tie rods behind spindles, easier with a steering box). Front steering is easier to achieve with rack and pinion steering than with a steering box.
These illustrations show the differences, and similarities, of our suspension and the new suspension.
I've seen mention of roller bearing (inner) LCAs but haven't found any. There is a good reason for this, as the LCA swings up and down it is forced to rotate along its axis by the strut rod movement. I estimate this rotation to be around 20 degrees. If the LCA cannot rotate at the inner joint the LCA would have to twist or the strut rod would have to flex (bend). The LCA also has some side-to-side movement.
The strut rod also has to swing up and down, side-to-side, and rotate along its axis, which is why it is connected to the frame the way it is.
The new (introduced in 2015) Mustang front suspension gets around this by using what they call a double ball joint connection at the spindle, with the LCA, (lateral link) and the strut rod (tension link) both connected to the spindle with ball joints (see illustrations below). This also allows a more positive connection of the LCA and strut rod to the frame, as they only have to swing up and down and have a little side-to-side movement, but no rotation.
Another big difference is that the new suspension has front steering while ours have rear steering (tie rods behind spindles, easier with a steering box). Front steering is easier to achieve with rack and pinion steering than with a steering box.
These illustrations show the differences, and similarities, of our suspension and the new suspension.