So I got a busted rear u joint on the front driveshaft. I understand that you can drive with 1 shaft by locking the diff, however are they negative affects of doing this for a prolonged period? Can I hit 55 mph for 60 miles or is that pushing it?

 

I did it for about 2 weeks while rebuilding mine. But then again, I'm too dumb to notice any damage until something falls off. Imagine that the rear end and that rubber disc at the end of the drive shaft might protest at some point. I stayed like 50 mph on flat ground. I guess you just have to decide how much of an emergency it is.

 

this past summer I took the frt shaft out to have a friend of mine who owns a auto repair shop replace the u-joints........It took him a month to get it back to me......meanwhile with the diff locked I drove it as I normally would.....no probs, and for what its worth...negligible gas mileage improvement.

 

Did it fail cause you haven't been greasing the u-joints twice a year, if that is the case, I wouldn't drive hast do hard excellerations or drive for long cause your other u-joints are probably just as bad.
As for replacing them, as a 96, you probably should replace all your joints to prevent this from happening again and then grease them twice a year.

 

Yes you are correct as I had not greased them. For now I have ordered 2 u joints for the front shaft. Due to my "lack of funds" I will ride the rear until it shows signs of wear (I will grease it though). As for right now, I am driving on the rear shaft. Accelaration is much quicker then before and gas milage is substantially better. However I have noticed a slight play in the transfercase while switching gears that I would usually only experience in 4 low. Anyways everything is working out. Thanks

 

Binding may have thrown off your mpg, when I had my front shaft out did not see a big change, others have reported similar.