XM757 frozen drive shaft

[rdixiemiller]

Bjorn
Knock the u-joints out. Get 2 short pieces of steel rod that will just fit through the holes in the driveshaft where the bearing cups go. Insert rods. Place a pair of 10 ton hydraulic jacks between the rods, one on each side of the shaft (use steel or oak cribbing to make up the length). Start applying pressure. That way you will apply pressure in the exact direction you need to get the thing loose. The steel rods should reduce the chance of damaging the shaft that can result from over enthusiastic use of BFH. You can apply pressure up to the point the rods start to bend, then heat with a torch. I can't see the driveshaft resisting that force.

 

[WillWagner]

How about quenching it? Get it real hot, then put it in very cold water. I've removed fan hub adjusting bolts like that.

 

[cranetruck]

Before you chop it up Bjorn, send it to me. I'll gladly drip some sweat on it. Here's an Idea I had, using the chains similar to what you did could you suspend it from the crane and attach the other end to the pintle or a bed anchor and try to pull it apart with the crane?

Did use the crane exactly like you suggested, but some unhealthy movements resulted near the crane mount, that's why I did the tree thing in image above. May try the dual chain method next.

The avatar to the left here shows how much trouble we had removing the drive shaft before the trip. We tried loosening it by towing the 8x8 over some rough terrain and ended up busting Jason's tow bars. Finally the axles separated enough to get it out.

Question: If a part like this one is torched and quenched in water, how does that effect the original heat treatment of it? Splines are hardened, correct?

Robert, I rather not knock out the "cross" if I don't have to.

 

[steelsoldiers]

If you do knock the cross out of the female end, take a look at the plug in the end of the yoke. I had an old Chevy drive-shaft that under extreme compression off-road popped the cap/plug out of the end of the yoke revealing the male splined shaft. If the cap/plug is removable on your drive-shaft, you could chuck the female yoke in a press and use a piece of bar to push the male end out.

I can't tell from the parts diagram if you have a plug there or just a zerk fitting. If it is just a grease fitting, you could drill the end out to around 1/2" so you could use a 1/2" solid bar to press. Then, once you get it apart, you can tap the hole you made for a 1/2" NPT to 1/4" adapter to put the zerk back in.

 

[cranetruck]

Hmmm..with enough doctors on the case perhaps we can lick it.
I have seen the plug and it's very small, 3/8" or so, I'll have another look.

 

[TheBuggyman]

(I love that!)

Have a new one made. Will you really trust it after all of this force has been applied to it?
Bring the old one for an example so the new one will match in appearance, what will you be out, $500? You've already spent that two times over in wasted time.

FWIW, I hope that you get it apart! (I'd still use it as a spare at that point.)

 

[Stretch44875]

Had the same thing happen to the front driveshaft of my truck, froze for no apparent reason. put a hole in my heavy-duty work bench and used a jack and chain to pull it apart. Shaft worked fine after cleaning and putting back together.

I would go with Robert's suggestion. Having spent many hours freeing stuck shafts at work, found out having a straight pull is very important. Ball joint press works nice for taking apart u-joints

I figure you did, but is the cup spun off of the yoke at the splined section?

Just thought of this, any way to put a hydraulic pump on the zerk at the splines? Maybe use the pressure from the pump to force it apart.

Good luck!

Dennis

 

[cranetruck]

It's a hobby. Time isn't the same as money, better than watching TV. I think I can find a "new" one from a parts truck anyway. Meanwhile I'd like to know what happened to this one.

 

[TheBuggyman]

I realize that it is a hobby. (I have one too!)

It would just seem prudent to pick and choose the battles as opposed to applying deadly amounts of force to free an old driveshaft.

I applaud your efforts to win the fight and agree that it is much better than watching TV,
I suppose that I do not have the patience for doing stuff like that and I wish you the greatest of luck in your endeavor!

(I still love that!)

 

[DDoyle]

My thought was similar to Chris's, but was thinking - first, grease it, a lot - if the splines have rusted in place, they will form a seal, and the incompressible grease will force the shafts apart (of course, any leak will defeat that).

Next thought, remove the grease fitting and tap hole all the way. Screw in long grade 8 bolt, and thus use it as a screw jack to force the pieces apart.

Failing that, shop for replacement.

Good luck!

David Doyle

 

[Rattlehead]

Take that grease zerk out and spray in half a can of PB Blaster, GM Heat Valve Lubricant, or whatever your favorite break-free spray is. Let it sit upright for a couple days so the solvent soaks into the contact point. Then try one of the straight line pull ideas. PB blaster works wonders if you give it a little time.

 

[Recovry4x4]

As Chris pointed out, it looks like a steel cap inside the end of the slip yoke. Removing that one joint and the steel cap sets it up for the hydraulic press. Only thing is the only hydraulic press you have there is the deuce right?

 

[rdixiemiller]

Bjorn
That slip yoke was splined with a broach. That plug is basically a freeze plug, and can be removed like one. Pop that joint out and you can put a bar in there and press it out. The plug will go back in, just smack it with a hammer to get it expanded again.

 

[TheBuggyman]

Well, I might as well pipe in with an idea other than replace it.............

I have a buddy who installs underground cabling and they have some small dozers with a vibratory "knife" that helps them ease through hard soils. Perhaps if you could find someone with one you could hook it up like in one of your first pics......
That's how they remove old pilings from the mud too.

My other idea is to get a tub of Varsol or light machine oil, place the entire shaft in it and hook some sort of high frequency "personal massager" to it and let it soak.
(Keep it clean people!) Perhaps this will work the fluid in?

Some ultrasonic humidifiers work on this principle as do jewelery cleaners.

If you can get to Fredericksburg, VA I can arrange the dozer/vibration/thingy.

 

[67Beast]

I've had good luck on a stuck shaft on my off-road Jeep using grease like David Doyle sugjested. Just keep pumping the grease through the zerk and use the grease to hydraulic the shaft out.

 

[cranetruck]

Thanks for all your advise!
We tried the grease pumping method in Oklahoma and it didn't work.
Removed the cross today and enlarged the freeze plug hole for a ram. No shop hydraulics available, so I'll try a BFH later.
As far as penetrants, I have used CLP, GM heat valve lube, PB blaster off and on for several months.
There is no trace of rust or water just grease inside.

I have found a replacement, so this is now academic, but it will come apart.

Image is view without freeze plug.

 

[timntrucks]

i dont know what to say im like you it would come apart one way or the other. TIm

 

[DDoyle]

No shop hydraulics available, so I'll try a BFH later.

Knukleboom sounds like a fine replacment for a press!

DD

 

[cranetruck]

Right you are David, just a little much to set up that's why I wrote shop hydraulics.

 

[SierraHotel]

It would just seem prudent to pick and choose the battles as opposed to applying deadly amounts of force to free an old driveshaft.

I agree with Buggyman...don't let your single minded goal to get it apart override your common sense. I know I get to the point that “it WILL happen!” Fortunately it hasn’t killed or injured me yet…but it sure has scared the shit out of me…