Exactly what's in my truck,as for front and rear ends?I understand the vin tag but if someone replaced them at some point.also what the diffence(if it applies to my truck)between heavy duty and super duty.mine is 93 f250,4*4 auto.I do know I have the full float rear.thanks all

 

Tofigure out your axle ratio put a white mark or piece of tape or something on your drive shaft. Then roll the truck forward (or back) one tire revolution and count how many times the mark on the driveshaft goes by. I could be off a little on the actual numbers (someone here can correct me if I'm wrong), but if the driveshaft turns about 3 times for one tire revolution you have 3.08:1 gears. Three and a half times is 3.55, three and three quarters times is 3.73, a little over four times is 4.11. Four and a half times is 4.56.

"Super duty" is either a pre '98 truck that's heavier than an F-350, or else it's a '99 or newer F-250, F-350, F-450 or F-550.

As far as I know, "heavy duty" was only used officially on F-250s. There were two different ratings on F-250s, somewhere around 7000 lbs GVWR (light duty) and around 8400 lbs (heavy duty). There were also light and heavy duty half tons early on, but they were called F-100 and F-150 repectively. But "heavy duty" can just be window dressing and not really mean anything specific too.

By the way, the light and heavy duty F-250 distinction got really important in '97 when the light duty looked like the new F-150 and the heavy duty was still an OBS. Ford figured out that wasn't a "better idea" and changed the named of the light duty F-250 to be a heavy duty F-150 and the heavy duty F-250 became just an F-250. That distinction in '97 is a real pain when you're buying parts! People keep trying to sell me parts for the new body style light duty F-250.

 

IIRC, on those years, SD was F-450+ (essentially), and if your truck had a full float in the rear originally, you have an HD. There *should* be tags on each axle for ID (somewhere). You can also count revolutions of a wheel when you turn the pinion or count the teeth (hard to do with the D50 TTB you should have under the front).

-Mike

 

Good point. If you've got the diff opened up you can divide the number of teeth on the ring gear by the number of teeth on the pinion. That'll give you the exact ratio.

 

Cool thanks guys.I'm almost positive its bone stock,but never know.and I've seen heavy duty/super duty badging on my style truck,maybe some yahoo changed it??I've just noticed something on mine,when it gets about half way up on temp.gauge the abs and parking brake light comes on.it happend about 3 times in past week.I'm 99% positive I need a new tps,and that acts up to,would these two go hand and hand?if I confused the **** out of you let me know.thanks all

 

sterling 10.25 rear,
dana 44 or dana 50 ifs front.
the easiest way to tell what the front axle is is by looking at the locking hub in relation to the mounting flange on the axle
the D-44 is slightly smaller than the flange, the D-50 is the same size.
here is a pic of a D-44:

and here is a D-50-D-60:

 

Also, every Dana 50 TTB I have encountered has the number 50 cast into the bottom of the third member.

 

Ill have to look tommarrow.I have the auto locking hubs.