hp loss

[Greg Hermann]

>> >On Fri, 12 Mar 1999 Jason_Leone at amat.com wrote:
>>
>> >A big factor is the rear axle gearset and especially if it is a hypoid
>> >design and also [I think] how much the actual offset is between the ring
>> >and pinion centreline; the greater the offset, the longer the pinion tooth
>> >becomes, thus increasing friction. I notice spiral bevel gearsets coming
>> >back into production and I believe it is because of the greater drag of
>> >the hypoid design.
>>
>
>Someone is making a 9" Ford center section that takes 12 bolt GM ( or maybe it
>was Dana 60 ) R&P gears because they were slightly more efficient. If my memory
>is correct, it was due to the dimension differences , maybe the pinion was
>mounted lower............  don't know about these things    Tom S

A twelve bolt and a Dana 60 both have about half of the pinion axis drop
below the centerline that the Ford 9 does. Guess would be that a 12 bolt
ring is nearly as strong as a 9, Dana 60 is a BUNCH tougher--but neither
has the nose bearing for the pinion--which adds a LOT of stability to the
gear mesh under load. (If you doubt the significance of the nose bearing
for taking heavy torque loads well, check out the design of any heavy truck
or heavy equipment center section, Rockwell, Eaton, ZF, anybody's1)

No question that less pinion drop in a hypoid gear set= less sliding = less
friction = less heat & more efficient, but as Gary pointed out, how much??
I dunno!

Regards, Greg