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U-joint Dis-assembly

Posted: Sat Mar 15, 2014 7:18 pm
by Bamboo812
I'm trying to remove a 1978 R100RS drive shaft from a swing arm prior to sandblast and paint. What is the preferred method of dis-assembling a u-joint? I have the Ed Korn tool for removing the drive coupling, but there isn't enough room on this drive shaft to use it, without removing the u-joint flange first. I tried punching a hole in the cap plate covering the bearings, but it's tough! Any clues before I fuck something up?

Re: U-joint Dis-assembly

Posted: Sat Mar 15, 2014 7:33 pm
by audiowize
I just painted my R50/5, and I ran into the same conundrum.

While I blasted all the other parts, for the swing arm, I heavily taped up the drive shaft, then used a wire brush on my grinder to peel the paint off and prepare it for paint.

Re: U-joint Dis-assembly

Posted: Sat Mar 15, 2014 9:00 pm
by ME 109
Isn't the 'bell coupling' (fd end) held on by a rather large nut?

Re: U-joint Dis-assembly

Posted: Sat Mar 15, 2014 9:28 pm
by Bamboo812
Yes, and it's on a tapered shaft. I gave it a few good whacks after loosening the nut, but it didn't come off. I don't want to take a chance on damaging the swing arm or drive shaft. The tool I have exerts major force to pop the drive coupling loose, but it is about 1/8" too thick to fit in the gap provided. If I can remove the X piece in the U-joint, then I can push the drive shaft further into the tube and it will work. How did you remove the end caps, or were they pounded out when your uni disintegrated?

Re: U-joint Dis-assembly

Posted: Sat Mar 15, 2014 9:35 pm
by ME 109
I did need to to some persuading with a hammer etc, but my uni-joint was no longer 'staked in place' as yours will be.

Got access to an oxy torch? Careful tho!

Re: U-joint Dis-assembly

Posted: Sat Mar 15, 2014 10:05 pm
by blitz
Gear puller.

It's been a decade, but I think i remember taking mine apart using a gear puller and heat. I had a bad cardan joint, and needed to extract the drive shaft from the swingarm. Heated the hell out of the drive coupling, and used force and impact (hit the gear puller with a hammer) to free the coupling from the shaft. impact is your friend.

Once the driveshaft was out, i was able to grind down the stakes which held the cardan joint with my dremel tool.

I used my vise and some sockets to remove the cardan from the yokes. poor man's press.

after a decade of looking, I found what looks to be an acceptable replacement for the cardan joint. theujointstore.com (why didn't i think of that a decade ago?) has a 1-0475 Neapco joint which looks to fit. My plan tomorrow is to reassemble my 4-speed trans (fit shims, put on the cover), and install the cardan into the yokes. at $28 with shipping, much cheaper than the $200+ bmw charges for a driveshaft. hopefully, i assemble it tomorrow.

As an aside, if you're thinking of using solder for measuring transmission bearing socket depth, don't. use shim plate.

Re: U-joint Dis-assembly

Posted: Sat Mar 15, 2014 11:22 pm
by melville
OK, you do have an early shaft. Gear puller, bearing separator, and hammer, working together.

First, break the nut free and unthread it about halfway off. I clamped the u-joint between a couple pieces of softish wood in the vise.

Rotate the shaft until you find the spot where it comes out the furthest.

Slip the bearing separator behind the bell, and engage it with the big 2-jaw puller. Crank on the puller bolt. Tap it lightly with the hammer. Crank some more. Tap. Crank a bit more than that. Tap. And still a bit more. I'll just say it takes a fuck of a lot of force to break that motherfucker.

Eventually it will release. Here's where you'll be glad you left the nut loosely on the shaft. It's *rumored* that without that nut the shaft might launch and leave a *barely* noticeable dent in the side of your 1965 Standard Microbus. But we're above trafficking in rumors here.

Good luck!

Re: U-joint Dis-assembly

Posted: Sun Mar 16, 2014 1:38 am
by Garnet
melville wrote:OK, you do have an early shaft. Gear puller, bearing separator, and hammer, working together.

It's *rumored* that without that nut the shaft might launch and leave a *barely* noticeable dent in the side of your 1965 Standard Microbus. But we're above trafficking in rumors here.

Good luck!
The only time I did it I fired the shaft all the way across the shop. I'm sure glad my bus wasn't parked there as I think it would have gone right through the side. :oops:

Re: U-joint Dis-assembly

Posted: Sun Mar 16, 2014 2:45 am
by Duane Ausherman
If you think that a 12 gauge slug is dangerous, experience the whole driveshaft flying when that coupling comes loose. It will sound like a 30-06 rifle.

Re: U-joint Dis-assembly

Posted: Sun Mar 16, 2014 10:29 am
by bigfella
I had access to a 50 ton press when I pulled mine apart. The 5 ton press I had at work would not budge it. And yes it did sound like a rifle when it let go.