Transfer case operation ABC's?

[Wolfy]

Will someone please explain the workings of the "transfer case"? (Re. 07. 5, 6. 7, 68RFE, 4WD, 3. 73)



Assuming functions are the same, whether electronically or manually controlled (correct me if this is not so) , ... exactly what is the gear-ratio change between Hi and Lo? (I. e. , how is the overall drive-train ratio affected?)



Is this change effective in both 2WD and 4WD?



Is there a link to some info-source for transfer case specs(Ram site, etc. ) ?



I am too ignorant of this feature to know what other questions to ask.



Any explanation of the workings of the transfer case would be appreciated.

 

[Jeff_K]

Assuming it is the same transfer case as used on the 03+ trucks the gear reduction is 2. 72:1 when in 4lo. There is no gear reduction in 4hi or 2hi.

 

[RodMorris]

Well, it works like this:

4HI basically connects the front and rear driveshafts together so there is power going to both axles. There is no differential front-rear like there is in the axles side-side, so 4WD can't be used on hard, dry surfaces or there will be major binding in the transfer case gears.

4LO does the same thing except it adds a 2. 72:1 gear reduction to both axles. With my G56 and 3:73 axle gears that's almost a 70:1 reduction at the wheels! Needless to say, that torque is amplified through the whole drive system so it can be pretty easy to break something if abused with the Cummins power.

 

[Wolfy]

Thank You

Well, it works like this:



4HI basically connects the front and rear driveshafts together so there is power going to both axles. There is no differential front-rear like there is in the axles side-side, so 4WD can't be used on hard, dry surfaces or there will be major binding in the transfer case gears.



4LO does the same thing except it adds a 2. 72:1 gear reduction to both axles. With my G56 and 3:73 axle gears that's almost a 70:1 reduction at the wheels! Needless to say, that torque is amplified through the whole drive system so it can be pretty easy to break something if abused with the Cummins power.

Thanks Jeff and Rod,



I appreciate the replies!