Half Shaft U Bolt Removal

[Mark S.]

I am having trouble removing one of the half shafts on my '67 small block. I have loosened the nuts holding the U bolts on the differential end but I can't get one of the U bolts free. I am using a pry bar to push on the nuts that are on the back of the U bolt.

Is it time to break out the MAPP Gas torch? I have been soaking the U bolt with PB Blaster and tapping with a hammer for a few days. Any advice would be greatly appreciated. Also, is there any danger of the torch hurting the differential? I am replacing the half shaft U joints so I am not worried about them.

Thanks in Advance,
Mark

[Joe L.]

Re: Half Shaft U Bolt Removal

Mark-----

I'd be very cautious and reluctant to use a torch. You may not damage the differential but you may well get the stub axle hot enough to destroy the axle seal. Then, you would have to remove the differential carrier from the car in order to remove the stub axles and replace the seals.

Is the u-bolt obviously and heavily rusted?

[Mark S.]

Thank you Joe.

Joe,
Thank you very much. Based on your comments, I will not use heat as I don't want to damage any seals and create more work. The U bolt is rusted but not heavily. I am able to wiggle one leg of that U bolt but the other leg is frozen. I will keep dripping PB Blaster on it and tapping it with a hammer until I am able to pry it out.

[Joe L.]

Re: Thank you Joe.

Mark-----

Based on you description, I think you will be able to eventually get it loose if you keep after it with the PB Blaster and keep applying pressure with a pry bar.

If, for some reason, this does not work, there's something else you could do. Use a cut-off wheel on a die grinder to cut the u-bolt. Then, the one side that's loose will fall out and you can rotate the other side until it breaks free and comes out. You may "nick" the u-joint bearing cap in the process, but that's no problem because you should be replacing the u-joints, anyway. Always replace both half-shaft u-joints if you have the half shafts out and the car has any significant number of miles on them. However, I absolutely do not recommend trying to change these joints yourself. These are WAY harder to replace than drive shaft u-joints and you may damage the u-joint flanges in the process. Take them to an experienced driveline repair shop and let them do it. The cost is usually very nominal if you get the u-joints from them.

You should also replace the u-bolts. Use GM #2066840. The driveline shop may also be able to supply to with equivalent bolts.

[Chuck R.]

Re: Half Shaft U Bolt Removal

If you can grab the edge of the u-bolt where it loops around the joint cap, use either a small punch or small chisel and try to drive it out. You can't do much to hurt anything as long as you stay away from the yoke. If you beat up the u-bolt, it's no big deal to replace. If you beat up the cap around the edge a little, again, it's not a big deal as long as you don't cave it in or shatter it.

If you can't get a purchase as described above, then personally I would use the small sacrificial screw driver and file/grind the blade super thin so that it will chase between the two. Start where the cap and u-bolt first touch and wedge it in.

Even if you spread the u-bolt open during the process, it can be easily bent back into shape with a vise. Just put the nuts back on to protect the threads and close it back up.

If that doesn't work, then as described in the other posts, just cut the u-bolt and get a replacement.

Heat on high stress components such as driveline joints and yokes is a real "no no" Mark and should be looked at as a "last resort". As Joe stated, the heat generated will usually transmit and ruin the seals and then impact the greases/oils and or fuels. Also, be aware that high heat will ruin whatever tempering metal parts may have.

Unless your adept with the use of torches, I'd stay away from it.

Chuck

[Mark S.]

Thank You Chuck and Joe

Thank you to both of you. You have some great ideas that will be very helpful. We are having a snow day today in MA so after snowblowing the driveway I was PB Blasting, tapping and prying the U bolt. I will give it another try later. I have been trying to remove the trailing arm, strut rod and half shaft since Xmas vacation to send to Bair's for a rebuild.