Got it. I'll suggest an alternative to Andrew's suggestion, to get at the same issues he's after in another way. I do think you should try both and do what works for you.
1.) Make it a habit to practice broken octave scales at a relaxed and comfortable tempo, trying to maintain legato and evenness at all times.
2.) With a metronome set at one tick per 16th note at a relaxed and comfortable tempo, practice the passage in exaggerated 2-note slurs that start on the low note and end on the high note, with the hand dropping from the air and landing ff on the low note, then lifting up into the air as you play the high note pp. The 16th note metronome is to verify that you are absolutely even. This step gives you practice keeping a beat with the low notes.
3.) Do the same thing, but this time the slurs start on the high note pp and end on the next low note ff. Now the slurred groupings are not the same note. Some of the stretches will be a little big but it looks like the largest is D to B flat, which will be fine for you if you have a comfortable 10th. Since you're now ending the slur ff on finger 5 (or 4 if you prefer for the black keys), use a different hand movement: drop down gently on the high note, then swing your hand and arm sharply down and to the left like you're trying to swat a fly that is sitting on the low note. This gets the weight of your arm and hand behind the finger. This step gives you practice arriving decisively on the low note to help you keep the beat with the low notes, and gives you practice maintaining legato between the notes that are not exactly an octave apart.
4.) Practice as written. Keep the 16th note metronome until it's easy to stay even, then switch to 8th note, then quarter note, then no metronome. Musically, I'd recommend placing slurs like so
clementi.png [ 566.78 KiB | Viewed 2070 times ]
and use finger legato during the slurs, maybe a little pedal for color, but don't rely on pedal for legato. Find a hand movement that supports what you're playing. My teacher would probably want me to use wrist rotation like turning a doorknob back and forth, unless finger 5 or 4 sounds too weak, in which case the fly-swatting movement works better.
Arrive decisively on the downbeats (that's what step 3 was for) and make little crescendos during the slurs. You might choose bigger crescendos on the slurs in which the right hand is helping to emphasize arrival on downbeat with those chords, smaller crescendos on the slurs with no RH involvement. Or you might choose to do the opposite.
PS Since I don't have a comfortable 10th when it's a major 10th, I'd probably move the slurs over one 16th note so that the finger legato concludes with an octave leap and the leap of a 10th occurs in the air. Musically that would still support arrival on the downbeat.