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Why is the Centre of the Diff nose on an Atlas Off set?
Antnicuk - 16/5/11 at 09:02 PM

Been looking at getting my atlas diff and my gearbox a bit better aligned in attempt to address the vibration i have and noticed that the diff nose if off set from the centre by about 2-3 inches and just wondered why? Was the original ford engine/gearbox set up not in the middle of the car? i cant think why else the diff wouldnt be in the centre?

Does it matter if i have the diff and gearbox offset both vertically and horizontally if the angles at each end both match?

deltron63 - 16/5/11 at 09:16 PM

So the uj's can work properly

blakep82 - 16/5/11 at 09:16 PM

think its just because the half shafts are equal length, which means the crown wheel is slightly off to one side, and so the pinion is off to the other?
since the crown and pinion are individual items (there's only one of each in the axle) maybe it makes it cheaper to make all half shafts the same? i guess its more expensive to make them different lengths.

i understand you shouldn't really have a prop perfectly in line as it has asome bad effect on the UJ bearings (so i've heard) maybe it also ensures the prop is never perfectly in line and perhaps the bearings last longer if thats the case

ashg - 17/5/11 at 07:38 AM

nope all wrong they did it to reduce noise

adithorp - 17/5/11 at 08:20 AM

quote:
Originally posted by ashg
nope all wrong they did it to reduce noise


Yep, it's a hypoid gear and they're offset in order to be quieter. There's an explanation in CompleteKit Car mag a couple of issues ago.

The Prop flanges should idealy be offset but the centre lines parrallel. This means the needle roller bearings in the UJ's move, so don't wear as quick as they would if continually sat loaded in the same position. The flanges/centre lines have to be parrale lto cancel out the movement in each other. Have a look at BaileyMorris site for an explanation.

Antnicuk - 17/5/11 at 04:46 PM

thanks chaps, very helpful

MikeRJ - 18/5/11 at 08:18 AM

quote:
Originally posted by adithorp
quote:
Originally posted by ashg
nope all wrong they did it to reduce noise


Yep, it's a hypoid gear and they're offset in order to be quieter. There's an explanation in CompleteKit Car mag a couple of issues ago.


A hypoid gear will have the pinion set below (or above) the centerline of the crown wheel. I was under the (possibly incorrect) impression that Antnicuk was wondering why the pinion isn't centred between the wheels, rather than top and bottom of the axle?