Rear Axle question

[SeanBob]

I am currently shopping for a '96 to '98 Z-71 extended cab truck ( 1500 series ), and have a question. I've found that a few of these were equipped from the factory with a 14 bolt rear axle. Was this a heavy duty option that had to be ordered, and if so, what else does this include or tell me about the truck? The vast majority of these have the typical 10 bolt with Gov-lock differential. I assume the 14 would be the more desireable. Also, what else should I be aware of in looking at these year models? Any help greatly appreciated. Thanks!

[Ben]

My bet is that those "1500's" were really 1500HD, which is a 3/4 ton truck with a 1/2 ton badge.

 

Marketing stuff this, as the 2500HD is really a 1 ton truck.

 

Difference between a 10 bolt, 12 bolt, 14 bolt is sizing. Bigger.

 

Like a 10 bolt will have an axle gross weight rating of something like 4,000 lbs and a 14 bolt FF will have a 6,000 lb gross weight rating.

 

Known weak links for any GM 1500 is the auto tranny and diff (10 & 12 bolt).

 

Exacerbated if larger than stock tires, as it reduces the effective diff ratio by same percentage diff in dia (lower numeric).

[bkoder]

It is a heavy chassis equipment option and it included a haevier spring pac and heavier rear drum brakes.

I had it on my 98 and I know the limited slip worked a lot better then the one that was in my 93 that had the 10 bolt style rearedd.

[westex39]

I had a 99 Z71(old body style) with the HD chassis package. This included the 14 bolt SEMI-floating rear axle. This was the axle that Chevy used on the light duty 3/4 ton trucks. Heavy duty rear drum brakes and heavier duty springs were also part of this package. To my knowledge this option was not available on the new model 99's. Gross vehicle weight was 6600 pounds, vs. the normal 6200 pounds for the regular 1/2 ton.