Remove stuck driveshaft bolts?

[KatahGii]

Ok so I’m trying to unbolt my driveshaft at the rear diff so I can easily take out my sending unit again. I think the float is stuck on something. One of the bolts is stripped. I’d try an extracted socket but I can’t fit a ratchet and socket in there to get to the bolt. Any ideas that don’t make a spark since I’m so close to my gas tank?

[Dzimm]

Vise grips.  Next voice would be get a grinder/Dremel in there and try to grind new flat sides on the bolt and try again with a wrench.  Worst case, cut it off and drill out the yoke and go to true ubolt straps or get a new yoke.

 

I wouldn't worry too much about the gas tank.  I've had sparks flying all over around them multiple times, as long as the truck has been sitting for a day or too, there won't be too much for vapor floating around.  Just keep a fire extinguisher or two handy in case.

[Pete M]

yup, at that point I'd have to make a determination if ubolts or a new yoke is the easiest path.  and if I got a new yoke, I'd probably still drill it out and go with the little ubolts.   

[gogmorgo]

I like to use the box end of a wrench on them. A socket would be better, but you may have to spin the driveshaft to get the socket on straight. 
If you can’t grab it with vice grips, Heat. Get that bolt head as hot as you can get it. A propane torch or larger butane torch might work for something that small. Hit it with a welder, maybe. You might not have clearance to weld a nut on in this specific case, but maybe a bolt would work instead, or something else you can grab onto and spin. The heating and cooling stretches and shrinks the bolt, which can help break the threads free.

 

If heat isn’t really an option, you can take a punch or chisel and give the bolt head a good smack with a hammer, on either the face or the flats, or if you’ve got a through hole, even the tip of the bolt – just take care not to mangle threads. The shock on the bolt can also help break free any corrosion or whatnot on the threads. It’s less successful than heat, but might just be enough.

 

Your bolt is mangled anyhow, so it needs replaced. A new ujoint strap kit will come with new bolts. These bolts will have smaller heads than the standard ones out of the bolt bin for clearance reasons, so it’s worth getting the “correct” bolt.

Before you run a new bolt into the hole, chase out the threads to clean them out. Don’t use a tap, you’re only trying to push stuff out of the threads, not cut new. If you don’t have a set of thread chasers, you can make one with one of the old bolts by cutting slots into it, perpendicular to the threads. 

[AZJeff]

I use socket head cap screws in place of the normal OEM hex head Bolts.  They are normally built to ASTM std. 574, which is better than grade 8 SAE.