DODGE RAM FORUM banner

1 - 6 of 6 Posts

·
Registered
Joined
·
11 Posts
Discussion Starter #1
hello my 03 1500 ram 4x4 5.7l hemi quad cab with a 9.25 rear end, 12 bolt diff cover and 12 bolt ring gear i counter 47 teeth on the ring gear and 12 and the pinion gear (divide 47 into 12= 391) that would give me a 3.91 gear ratio correct? my build sheet says its a 3.92 gear ratio why is the math different from what my build sheet says? it also says its a Anti-Spin Differential Rear Axle, i am in the process of buying a ring gear carrier, ring and pinion, and master rebuild kit from rock auto, while trying to find what parts i need i dont know excately which parts i need for excample whats it mean by empty case open differential or Open Differential (w/o Limited Slip) Carrier Case. whats the difference in a TracLoc Positraction, complete; 31 Spline; Loaded and a Trac Lok; with 31 Splines; the difference is those 2 parts are 125.00 bucks. i dont want to order wrong parts and thats just for the carrier case how about the master ebuild kit what will i need for that 1. im sorry if these are dumb questions but id do appreciate any and all help info if you need my vin # just ask thank you really thanks i need the help
 

·
Registered
Joined
·
319 Posts
3.91 by math, but they may call it 3.92, why? Who the heck knows. But on the ring gear with cover off it is stamped on ring gear. Spline count would be the axle. No idea with the carrier thing.
 

·
Registered
Joined
·
2,870 Posts
Please don't take this the wrong way, but have you ever built a rearend before? Or are you having someone else do it?
It isn't as simple as ordering parts and bolting them together.

The open differential is just a housing basically. Loaded will come with gears, unloaded will come empty.

I am not sure what is the difference between the 2 trak lok units as both appear to be loaded posi units.

Have you considered a used complete rear end from a wrecking yard?

Oh and as far as the ratio - 3.91, 3.92 what ever it takes :) They are the same thing.
 

·
Registered
Joined
·
230 Posts
Because your math conclusion is off lol.....47 divided by 12 = 3.916666666666667, which is as many places as my calculator goes before rounding up. Since axle ratios are never given in more places than hundredths, 3.916 would be rounded up (since 6 is larger than 5) to 3.92.
As paco said, if this isn't something you have experience with you may not want to try it the first time on your daily. Setting up rears, gear mesh patterns etc is almost an art form. Has to be just right or at best the gears will whine, at worst they'll self destruct and take your expensive new LSD with it. Open rear means no limited slip; your build sheet says anti-spin diff so you SHOULD have LSD from the factory. One thing you haven't mentioned is, what's wrong with what you have?
 

·
Registered
Joined
·
319 Posts
I will confirm without correct tools you probably wont have success. I built gears and transmissions for a race shop for more than 5 years and also Legengs cars. You also have to know where and how to measure pinion depth. Backlash has to be correct or youll end up with clunking or if to tight gears get to much wear and can loose temper.
 

·
Registered
Joined
·
11 Posts
Discussion Starter #6
thanks for everyone's help, 1st no I'm not doing I'm only ordering and helping put it back together(me learning) by a qualified Machanic ( good friend)
 
1 - 6 of 6 Posts
Top