Volks,
As a result of my transmission failure... not my month to say the least but
hey... I need to install a new transmission in my camper.

The tires are 215/85R16 - circa 30.3" tall

With a GPS reading 100km/h, the tachometer says 3050 rpm in 4th

The transmission is an AAN which is supposed to be 4.86:1 - same as any
north American gearbox

Both the transmission and front differential were rebuilt in 2000 in Germany
so who knows what has been done to them R+P wise.

Plugging these numbers into a calculator, this should result in (with a 0.85
4th) 2840 rpm and not 3050.   If you put 5.43:1 in the calculator, it
results in almost 3200 RPM.

So, I figured I could tell by putting the van in 2WD (via decoupler) and
lifting a front wheel and count how many times the drive shaft turns when
you turn the wheel once.   less that 5 means a 4.86 and more than 5 is a
5.43 right??? nope... I get about 2.4 turns of the drive shaft.  Now... in
my garage I have a 4.86:1 front diff... same test (hold one flange while
turning the other) results in about 2.4 turns of the drive shaft flange....
what gives?   Without lifting the vehicle totally off the ground and locking
all differentials and giving the wheels a revolution by hand, how are you
supposed to tell?

The last thing I want to do is install my spare AAN in there and have it
breaking because the front R+P doesn't match.
David Marshall

Fast Forward Automotive Inc.
4356 Quesnel-Hixon Road
Quesnel BC Canada  V2J 6Z3

Internet: www.fastforward.ca   Email: sales@fastforward.ca
Phone: (250) 992 7775

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