[ozzman]

I'm new to broncos (just bought my first 79) and i was trying to figure out what my front and rear axles are and their gear ratio. the vin on the door looks like this:

U15SLEE2600
104 8M U151 DB1 G 16A
06400 1979 76

I know it has the 400m in it but doesn't the "G'' mean a C4 tranny? i thought that 400's would all have the C6 if it was automatic?

The "16" is the rear axle code but i don't know what it means?
Same with the "A" for the front axle?

Any help would really help me out. thanks.

 

[highhorse78]

That might give you a hint, but because they coulda been changed out at any time in the last 30 years the only way to really tell is by checkin the ring gear in the diff

 

[Gillamonster]

if they are stock, you got a 9 out back and a 44 up front

 

[highhorse78]

Oh i forgot there is another way to estimate by jackin the rear up and countin the revolutions of the driveshaft and the rear wheel

 

[ozzman]

How would i check the ring gear? And if it is the 9" is it tuff enough stock for a rebuilt 429?

 

[ozzman]

And i forgot to say thenks for the help!!

 

[highhorse78]

No problem. pull the front diff cover off when the truck is jacked up, spin the tires until you come to the gear ratio or i.d. stamped into the ring gear. your front ratio will match your rear.

 

[ericautopart]

How would i check the ring gear? And if it is the 9" is it tuff enough stock for a rebuilt 429?

I'd say your in good shape with the 9".