Just thought I'd post these as a conversation starter for those interested in the workings of the 360 Box. Note the 3/4 and 5/6 layshaft gears just pressed onto the pinion shaft. No splines, no keyway...... Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
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Interesting. I am not sure I'd know where to start putting it back together - but that's why you're you and I'm me, right! Thanks for sharing, Phil. What was the problem that caused the box to be stripped and is it evident in the pics? Philip
very interesting, thanks Phil. Nice to have a REAL transaxle a la Porsche/Hewland, I didn't like the "T" boxes as much. brian
VERY NICE WORK. Must pay due respect. I hate gearboxes. On the three occasions I've actually tried to repair/rebuild a gearbox (and I hasten to add, very simple Ford units) they ended up making more noise afterwards than before. I'm too impatient to do the lash shimming and gear tooth contact patch checking at the right level of accuracy. Out of interest, why have you stripped it ? What was the problem ? Thanks, RF.
No major problem. Just a 360C check and refresh. (5000 track Km) New Bearings and 3rd/4th selector mainly. Also changed 5th/6th Ratios for 1.1:1 and 1:1. The std gears in a road car are a bit long and badly spaced for the track.
Phil, I've never cracked a 360 box. You say "3/4 and 5/6 layshaft gears just pressed onto the pinion shaft". You mean this doesn't have typical layshaft main shaft with 3/4 5/6 splined on the layshaft and all this going to pinon shaft to the ring gear? You gotta picture? Also, there is a way to alter the lockup of a limited slip. Can you describe how to change the lock-up and what effect would be noticed on the track. I've always had LSD but never really been without it so I really don't understand the real benefits I have.
Fatbilly I dont have any more pictures, and this box is all back in and running now. You can see the pinion shaft in one of these pictures. There isnt much else to see. Its smooth. The 3rd/4th layshaft gears are one item, as are the 5th/6th. they just have (different) interferance fits onto the pinion, and they do turn a little occasionally on 360C and GT (slicks). I've done one particular box 3 times due to it's mileage, and I really don't think it'll go again. But Ferrari say it only goes once anyway. There has been a small change in that there is now a snap ring to prevent longitudinal movement of the clusters along the pinion, but it still does not stop it rotating a little. Also note the burst loads of both pinion and crownwheel act directly on the bolts, and not on a referance casing surface, which means some considerable variation of mesh occurs under shock loadings....(The 430 has a much tougher side cover which incorporates the E diff mechanisms, but still has bolts bearing the burst loads.) The diff can be rebuilt with simply re-arranging it's own parts, or adding/replacing the shims and plates for different thicknesses. This only effects the static slip preload starting point, not dynamic lock up, although this will raise itself by the same amount static has been raised. % wise this is minimal compared to the effect of the ramp angles. Dynamic slip control is done most effectively by the ramp angles of the spider gear shafts and cups, and are not adjustable on a std car. However, Alternative spider cups and shafts are available now which can be configured in any number of ways.... But to be honest the 360 diff is actually pretty good in terms of its function anyway. It's just a little weak and expensive. It does benefit from being 10-20% stiffer on the static preload, but that's about it. Tightening the static preload improves traction/exit speed, and can reduce the instability under heavy braking. The 10-20% really increase I tend to do mostly has no negative side effects, but to lock it any more could induce understeer, most noticable in tight turns when wet. Depending on ramp angles in a race diff, you can run with zero static preload (like a 246) if you like, but the diff behaves better if kept tight with preload on a std car. All of this however is massively uneconomic to experiment with, as the diff bolts are stretch and can only be used once, and access on most models is labour intensive. The 360 however is actually quite asy and can be done between sessions at a race meeting if you like, but tuning the car elsewhere (shocks, springs, geometry, aero) reaps much higher reward.
