So my pinion seal is bad and leaks out all fluid above the pinion in a day or two. My question is if I just keep it in 2wd and low on fluid in the front until I can get it fixed will it still do damage or does the front differential only spin when it's in 4wd? There is no point in adding fluid when it leaks out this fast. Just seems to be a waste of money.

 

Things are turning when the truck is moving, so, being low on fluid could indeed cause you more issues. Need to fix that seal asap. Given how bad it is, I wouldn't be surprised if the bearing right behind is bad as well.

 

Ok thanks. I'll look into it asap then