Vin

[rolltider]

I have a 77 EB and am wondering about some of the codes in my vin#. It says it is a U151 and in the Bronco Graveyard catalogue this specifies a heavy duty model are these common or rare and what makes it heavy duty?

 

[Viperwolf1]

It's pretty common. The difference was in the spring rates mainly. Some of the HD packages came with a heavier duty rear axle. U151 didn't require an axle upgrade but the 3300 lb axle became optional with it.

 

[Viperwolf1]

I'd be interested in seeing your rear axle code (from VIN tag) and the rear gross axle weight rating (GAWR) from the driver's door sticker.

 

[rolltider]

The door sticker is missing but the riveted tag in the glove box says the axle code is J18 and the GVWR is 4600. Thanks for the info you gave me.

 

[Viperwolf1]

18 is the lighter duty (2900 lb in '77) axle with 3.50 gears and an open diff. J is the code for power steering.