Posted by Brian in AL on Wednesday, November 21, 2001 at 1:37PM :
In Reply to: Re: PW 1976 4X4 FULL TIME driveshaft removal posted by Todd J on Wednesday, November 21, 2001 at 11:14AM :
This issue comes up regularly. Better gas milage might be expected with part time 4WD as opposed to full time. However, both the transfer case and the hubs must be converted to a part-time system in order to eliminate friction from the front drive train. Even then, the result is often no significant change in gas mileage.
Removing the front drive shaft allows the front wheels and the transfer case to rotate independantly, but does not allow the front wheels to "free wheel". Thus, much of the friction in the front drive train continues to drain power from the system and fuel consumption will not decrease.
More importantly, the transfer case must be engaged in the "loc" position in order to transfer power to the rear wheels when the front shaft is removed. Prolongled use in this manner can (and will) cause damage to the transfer case.
I don't beleive your friend is getting any better gas mileage. I'm pretty certain he's not saving any wear and tear on his front drive train (except the drive shaft). And he's probably causing additional wear and tear to his transfer case.