rocketman4321

Well, five out of six ain't bad--but I've rounded one of the cap screws holding the front end of the driveshaft to the transfer case flange. So far I've tried other 6mm hex tools, drove in a piece of 1/4" hex, tried a screwdriver bit across the hex points, and tried knocking a groove in the lip of the cap and driving it with a chisel or screwdriver. No joy. A torx 40 is too small and a 45 too big. I can grab the head with the tip of a vise-grips but it just laughs.

I don't have a welder to make a hex shaft one with the bolt. I have an extractor but I'm pessimistic it'll work and the bolt looks hard to drill. I guess my next options are to dremel-tool a slot across the head and try a big-ahem screwdriver (I have one with a square shaft I can put a wrench on) or drill the head off. That would free the shaft, but will it move back by the height of the CV joint to clear the remaining stud? If not, should I drop the driveshaft or pull it back, cut the bolt a bit above the flange, move end of driveshaft aside, and remove flange?

Any other ideas? And yes, I did buy new bolts!

Thanks for the help!

georgeb944

Try inserting a fresh 6 mm hex tool and grasping it with a Vise Grip (the WR-7 is about the right size) and rotate both at the same time. Use a real Vise Grip with the rounded jaw.

If that fails, drilling out the head of the cap usually is enough to pop the head off. Choose a drill bit that is the same diameter as the shaft of the bolt. Once the head is loose, the rest of the bolt will spin out with ease (usually)...

tester123

WOW! I am not the only one that faced this problem. Here is what worked for me:

If you rounded out the bolt head, take the next appropriate Hex socket (bigger than hole) and pull out the bit from socket. Hammer that bit into the rounded bolt. Make sure the hex bit went all the way or as far as possible. I just did a simple measurement of the depth of "hole" and made sure the bit went in. After that it was just ratchet it out.
Like georgeb944 said, a vice grip would also add extra torque to turn the bolt loose.

I remember being so exhausted after getting this far and stuck with that bolt. Can understand... you can get through it .

rocketman4321

Thanks--appreciate the support! Maybe I'll go back and try the 1/4" hex again. Stepping up to the 7 mm is too big. I've cut down an allen key so it's straight--can pound that in and then just use a socket to drive it.

SloopJohnB@mac.com

New, the allen wrench or socket hex wrench has a chamfered edge that isn't conducive to broaching into a worn hex socket. The idea is to get a really good/tight fit into the rounded mm size socket head cap screw with a slightly larger SAE-size wrench.

Alternatively you can dremel a slot in the cap screw and use a flattened cold chisel to drive the bolt directly in (a couple whacks) and then angle the flattened chisel against the slot to drive the cap screw counterclockwise.

Another alternative is to use a hammer-driven manual impact wrench once you've either dremeled a slot or driven in a slightly larger hex key wrench. The trick is not to use a big ratchet or breaker bar, normal hand torque coupled with a small sledge (don't use carpenter hammers on cold chisels or on screwdrivers or impact wrenches!) will break loose or twist of the head of any socket head cap screw. This one is by Lisle but they're usually for sale at any automotive parts store with several heads for the ⅜ or ½" drive, including a couple of screwdriver heads. I've used this tool for over 40 years on British (Triumph) motorcycle and Jap bikes with those @@%% phillips-head cap screws on the primary cover and other places. I generally replace the phillips-head cap screws with hardened socket head cap screws and use blue loctite. The blue loctite will hold most anything and you can still disassemble without heat or corrosion, which is the real problem with steel caps crews into aluminum. If the aluminum is stripped out, helicoil thread repair works well but I don't think you'll have that problem with your driveshaft flange plate.

rocketman4321

I'll need to pick up one of those impact tools to have in the arsenal. But here's the trick that worked for me. I pried the flat metal "washer" strip (that goes under two screws) outboard, then hammered it back inboard. The strip slips outboard, but grabs the bolt a bit coming inboard and turns it a few degrees. Repeat and repeat. After about 90 deg of rotation the preload was off and I could rotate the bolt with a vise-grips or with the 1/4" hex I'd jammed in.
Obviously this is specific to the driveshaft bolts, but it's another trick to try.

Prospeeder

You should be able to use parrot pliers or super gripping channel locks to grab the head and twist them out. Vice grips dont have a grippy enough jaw compared to parrot pliers. other wise drill or chisel the head out, and then remove the axle> the bolt remains should spin right out not under load anymore.

tester123

Will have to remember this trick. When I did the way I mentioned, I was praying to GOD that this worked and what a relief when it finally turned.

tester123

This sounds logical to me. Since the bolt is not under tension, it should turn loose. It maybe a problem if there is some corrosion etc. holding the threaded portion...?