Is it possible? I cant break those flange bolts loose, ive exhausted all options. Those things are the devil...

 

No, you must have DS removed to service the Ujoint. Also keep in mind you want the vehicle pointing downhill (or put the back on jackstands) as the slip yoke of the transmission will pour fluid out when you pull the driveshaft.

Companion Flange bolts should have blue locktite and torqued to 80 foot-pounds. If they are rusted, you will likely need a yellow MAPGAS torch and a large Impact gun (something capable of 250+ ft lb). MAPGAS gets much hotter than propane, and you'll need a bunch if impact force to knock the rust loose down there.

Just did the pinion Ujoint on our duramax tow pig this week - amazing it hadn't exploded. There was nothing left, the needles had chewed away at the Ujoint itself. We did one in the dragster last year.

If you have a tool with lifetime warranty (snapon, craftsman, ect), put a wrench on the bolt, then another wrench (double wrenching) then smack it with a hammer. Either the bolt will come loose or it will bend a wrench. If it bounces too much, try with one wrench. You can also try a 3 ft breaker bar and some bodily force.

 

​​​​​​Its *** end is on stands, i double wrenched and my pneumatic is only 150 PSI also i only have a propane torch... Only a 3 ft breaker bar as well. I guess I dont have enough *** on hand to break these bad boys. Any other suggestions or tips or at this point should i just hire a hand? Bent a few wrenches and my gun sheared a couple sockets.
​​​​​​

 

How big is your air impact? A good name-brand 1/2" one and a set of black impact sockets should either remove the bolts or twist the heads off. I just bought a Milwaukee M18 2767 1/2" impact and it just laughed at the lugnuts on the dragster (150 ft-lbs 5/8" thread) with one impact hit. It buzzed off the trailer lugs like they weren't even tight. Our air impact isn't quite as strong at 120psi line pressure. (Never use chrome sockets, much less chrome wobblies, on an impact - they will explode easily)

I mean realistically speaking - unless they were given a bath of red locktite then ran in, they should come out super easily. The ones on my truck I don't even have torqued, just double wrenched.

All of the heat at the same time as the impact should have knocked them loose. Issue with heat, you don't want to burn the pinion seal.

When I've had to knock stuff loose on the truck without power tools, I lay on my side and put one or both legs against the frame rail and pull with both arms on the 3 foot breaker. Never had an issue.

 

I soaked mine in pb blaster a while then used a big breaker bar an had no trouble.Hitting it a few times also helped .
The press tool came in very handy on the u joints -the bigger pain to rereplace.

 

I had a devil of a time getting the bolts out of my '03 Ram 1500. Between the blue thread locker and a little rust on the back of the bolt, I really had to honk on them to get them loose. Once they broke loose, they came out okay. I was using an 18 mm ratcheting box wrench and a large pipe for leverage. I was using a 4 foot cheater pipe and it was still tight until they broke loose. I was afraid I'd have to get "Big Jess" out which is a driveshaft with the ends cut off. Now, I did wire brush the back of the bolts to remove surface rust and soaked them with penetrant.

 

When I have stuck bolts, occasionally I can break them loose by tightening them up a bit. Try tightening just a bit, if it moves at all try loosening. It's like they're friction locked, and going in the opposite direction breaks the lock. Word of warning, this can just as easily snap the head of the bolt off. I've also had luck using a sledge hammer on them. Put a 6 point wrench on, make sure it's good and solid, then hit the side of the wrench in the direction of travel with the sledge hammer. This is another one that can just as easily pop the head off as break the bolt loose.

 

+1 to using heat on tight rusty bolts. I don't think heat has ever failed me. Buy yourself a can of mapgas and give it another go. You can probably use your same torch head.
Fixed a car this weekend and the bolt holding the harmonic balancer on was super tight, 1/2 dewalt impact (330ft/lb) wouldn't take it off. Hit it with mapgas, tried again, and it came off.
​​Putting a wet towel near parts like seals will reduce the risk of hurting them.