front drive shaft spinning while in 2wd?

[CGALATE]

on a 2003 3500 47re, is the drive shaft supposed to spin? any explainations?



On my '95 it doesn't.



Thanks

 

[jelag]

your 03 doesn't have front hubs... even though the transfer case is in 2WD the front wheels are driving the front axles and the rest of the front drive train.....

You'd need a set of aftermarket hubs to prevent these parts from turning. .

 

[SierraRam]

Nature of the design like jelag said. The 2nd gens had a CAD setup.

 

[MChrist]

For those of us who don't know, what is a "CAD setup"

 

[EDankievitch]

Central Axel Disconnect. If you'd like to save some money and make your transfercase and everything that you don't want turning last longer when in 2 WD get a set of free spin hubs from Dynatraxx or one of the other suppliers The CAD set up can not be installed on the American axel that the gen 3 trucks use.

 

[MFranz]

Would converting to free spin hubs help with your fuel mileage?Seems like with those parts spinning all the time that that would be more resistance when going down the road. Anyone done one of these conversions and notice an improvement in MPG?How much does it cost to convert over to the free spin hubs and what is the process to put the truck into 4-wheel drive?Do you have to do each wheel individually?



Thanks

Mike

 

[SierraRam]

Would converting to free spin hubs help with your fuel mileage?Seems like with those parts spinning all the time that that would be more resistance when going down the road. Anyone done one of these conversions and notice an improvement in MPG?How much does it cost to convert over to the free spin hubs and what is the process to put the truck into 4-wheel drive?Do you have to do each wheel individually?



Thanks

Mike

I feel there are a four benefits that I have realized:



1>Increased fuel mileage an average of 1MPG.



2>Able to use low range in 2WD to aid in backing heavy trailers.



3>Since my truck is lifted the truck drives noticably smoother at highway speeds, no front driveline vibration issues since its not spinning.



4> Serviceable wheel bearings and better design helps carry the load of my oversized tire/wheels than the non-serviceable stock unit bearings.



Downside the intitial cost of the conversion.

 

[MFranz]

SierraRam,

How much is the conversion$$$. Did you do it yourself?How do you put your truck into 4-wheel drive?



Thanks

Mike

 

[amsoilman]

SierraRam,

How much is the conversion$$$. Did you do it yourself?How do you put your truck into 4-wheel drive?



Thanks

Mike

I'm sure he will get back to you on the cost associated with this conversion, but to answer your question regarding "How do you put the truck in 4-wheel drive", one gets out of the truck and manually engages the frobt wheels(both), then engages the transfer case into 4-wheel drive with the selector.

 

[Tinman]

I have the Dyantrac hubs and it is turning out to be one of my favorite mods. The reasons stated above are accurate, but I think I'm seeing more that 1 mpg improvement, maybe closer to 2. It is less conveniet to have to get out an lock the hubs but its so nice to be able to turn "off" the front end. The cost is about 2K depending on the vendor (Dynatrac, EMS, or the new one SpinTech (I think)). Options can run it up to 2200 -2500. I highly recommend the Dynatrac hubs. It isn't hard to DIY but it will take a whole day. I had the local machine shop press in the wheel studs and u-joints.

 

[EDankievitch]

Last I checked the Dynatraxx kit was around $1800. But if you factor in what rebuilding your transfercase and front drive shafts and everything else that turns when you are in 2wd and the fuel savings... . Well you can do the math.

 

[DennyDay]

Just had the SpynTech system installed on our '06 - - Total cost at MAD 4WD was just under $2k - - haven't had it long enough to find out mileage savings, but just thinking about replacing both front wheel bearings on my '01, cost over $1k - - looked like it was worth it. The machine workmanship on the SpynTech kit was outstanding. They use Mile Marker Hubs, with Stainless Steel Housings. All the bearings and seals are "off the shelf" Timkin and Chicago Rawhide. Took best part of a day for shop to install - - - had new ball joints installed at the same time - - new joints are greassable - - should last a long time

 

[rscurtis]

You are correct, that is the time to do the conversion, when you're in there anyway. I've had my Dynatrac system since March of '07 and would never consider going back to the stock setup.