FireDemonSiC

Hey guys. Just picked up a nice LS1 driveshaft a few days ago for my turd. I've had another LS1 driveshaft and a thirdgen 1LE style shaft in the past that I didn't have the best of luck removing the U-Joints from. I'd like to attempt doing this one now, but wanted to get a little diverse feedback first and see what everyone has to say about the subject.


It is a very well known fact to use a torch to heat the U-Joint cap and the "ears" of the driveshaft in order for the nylon retainers to melt and allow the U-Joint to come free. Now, I have seen a FEW people mention this and honestly I thought the same myself. The million dollar question is, what is heating the driveshaft sufficiently enough to cause the nylon to shoot out doing to the grain structure and integrity of the driveshaft?

Do you really NEED heat to get the old joints out? Nylon is a plastic, and relatively soft. Can a press "shear" off the nylon retainers and free the U-Joints without using any heat? Or is melting the retainers out the only way?

TTOP350

iTrader: (8)

I have always melted the nylon out. No issues.

FireDemonSiC

This driveshaft is being used on a 10.5:1 stroker sbc running nitrous. So I'm being very particular about details. Also, here is the other million dollar question. When heat is used, do the U-Joints HAVE to be pressed out while everything is still hot or can you wait until the driveshaft cools down?


I think putting that kind of force on the driveshaft while the metal is still hot is what I am most uncomfortable with.

RamIt

You are not putting much force at all when its hot. My caps came out very easy with just a little pressure when the plastic started smoking.

TTOP350

iTrader: (8)

A little propane torch from a hardware store will do it. Heat it till the nylon pops out like a zit then press them out hot or cold.

Is this a 3rdgen aluminum DS or 4th gen?

FireDemonSiC

It is a 4th gen shaft. 3" diameter.

TTOP350

iTrader: (8)

You'll twist that thin tube b4 you have Ujoint problems.

92RS_Ttop

iTrader: (3)

I didn't heat mine when I changed them last winter. I just stuck it in the press and the nylon broke pretty easily. Granted, I used a 12-ton HF hydraulic shop press instead of the little 1 or 2 ton arbor presses I saw most people using in the YouTube videos I watched prior to attempting it, so that probably made it a lot easier. I have the steel driveshaft though, the aluminum one may bend a little if you don't heat it first

FireDemonSiC

4th gen shaft is actually NOT weaker than the 1LE shaft as is commonly claimed.

TTOP350

iTrader: (8)

I just said its tube is a thin wall and that it will let go b4 the Ujoints will.
Buuuuut It is thinner. Compared to the smaller diam thicker wall 3rdgen shaft.
Any shaft can break/twist like a pretzel at any time.

FireDemonSiC

Do you have anything that shows the difference between the wall diameters of the two shafts? Always something I've wondered about.

TTOP350

iTrader: (8)

I used to have one of each shaft that was cut apart at a salvage yard.
The jys would cut them off right behind the trans yoke to keep them from leaking when they pulled the drivetrains. wasted a lot of good driveshafts.

FireDemonSiC

Wow...

Did you take any measurements? It is possible for the 4th gen shaft to be stronger even with a thinner wall.

TTOP350

iTrader: (8)

No I didn't but
4th is a larger diam but thinner wall
3rd is a smaller diam but thicker wall

Could be a toss up on strength but I'm not a engineer.

Night rider327

iTrader: (13)

Press or heat both works just fine. No you do not have to remove U joints while still hot. The heat is just to melt out the plastic that acts as a lock ring.

The temp to melt it out is very low. I can't remember the temp right off hand but I have used a harbor freight 1500 watt heat gun to do it in the past, also used a propane plumbers torch many times, even uses an oxy/fuel torch w/o turning the oxy on in the past.

Once the plastic crap is out, you can almost push the old U joint out by hand. I just used a socket and 16 oz. hammer to knock the joint out.

FireDemonSiC

FYI for anyone wondering, I stopped at the parts store yesterday and rented a balljoint press. I originally intended to torch and then remove the U-Joints. I started heating the driveshaft, but before it got hot enough to melt the nylon I decided to stop the heat and try without.

The U-Joints came out of both sides of the driveshaft WITHOUT the use of heat. Nylon retainers still fully in place. You just have to crank down on the press and after about 2-3 turns they'll "POP!" right out. The two U-Joint caps in the yoke would NOT budge this way. I actually observed the yoke ears beginning to flex a bit and the joint still wasn't showing any signs of moving. I'm guessing it is because both the joint caps and the yoke were steel/iron and corroded together a bit.


Anyways for the yoke, since it was cast iron I didn't have much of a worry about torching it. I heated that SOB until the nylon shot out and the rubber seals on the backside of the caps caught fire. Lol!

After I gave it the next 40 minutes to cool down, the U-Joint came right out with the press.