There's gotta be a trick to this...

[dbeardslee]

So I'm changing my FD to one off a 750 and everything is going sooooo smooth until I try to get the shaft back on the %$#@^&%$##@#$ u-joint. I can get it to where it feels like it's starting to line-up but then it won't go any further. I can spin the middle drive a little with finger pressure on the end of the shaft, but it just won't go in the hole. I tried tapping it with a hammer and a wood block on the end of the shaft, and I swear I can hear the thing laughing at me. I thought about using a BFH but I don't want to damage anything. Anybody have any pearls of wisdom they would care to inject here?

[Getty]

I had the same problem. In fact I think I tore muscles in my neck from that damned drive shaft. Got some great prescriptions out of the deal.

Your on the right track with the wood and hammer. I had to get it lined up, hold in place with wood (2x4 i think). Then knock that SOB in like I meant it. The first hard whack and it started to go in. One more whack and presto. That was such an accomplishment for me.

[jjwaller]

Take the clamp off the boot on the middle drive and seperate the boot.
It's tight, but stick a small finger in there and check the position of the universal joint. Make sure it is horizontal pointing at the shaft!!!!! Do not use a hammer until
it is definetely pointing at the shaft.
Like I said it is real tight in there, but it must be done!
Make sure to grease the spline before inserting it also.

[dbeardslee]

JJ and Getty - thanks for the replies. While I was waiting for a come-back on this thread I went out and did exactly what JJ suggested. Undid the clamps and took a look from the other end. I think I'm going to follow Getty's lead and hit it like I mean it. Very few problems can't be solved by the proper application of force

[dbeardslee]

I GIVE UP!!!!!...

...not really, but if I was a quitter, now would sure be the time. I'm pretty sure I'm getting it lined up, it just won't let it to go in the hole. This thing's starting to remind me of my ex. I've tried a BFH. I took the other shock off and moved the arm around and smacked it at different angles. I put a wheel puller on it and tried pressing it in. Even prayer doesn't work on this thing. I'm thinking about sacrificing a virgin to it - if I can find one, but that's my last resort. I'm getting pretty close to the stumped plateau.

[TopCatGr58]

Hey there DB,

Okay, there is that retaining compression ring that is at the end of the driveshaft, and that's what's NOT compressing to allow you to drive home the tip of the shaft. As was stated before, a liberal amount of grease on it, and the inside edge of the U-joint fitting can help it to slip/compress easier. Also, just as a thought, try rotating the ring so that the GAP is UP, so that with gravity, the ends of the ring will be laying deeper into the channel that the ring fits in. Perhaps the ends are HANGING up on the edges of the splines/shaft???

That's about all I can suggest, cause as long as you have it positioned into the U-joint end, then it's just a matter of the BFH being able to apply enough force to cause that compression ring to compress to allow the rest of the shaft to slip into position!
T.C.

[bikerphil]

750 FD

If I understand correctly, you are doing a 750 FD conversion and can't get the driveshaft into the u-joint because the locking clip won't compress. BTW, throw that clip away, it isn't needed anymore. It won't line up with it's original slot anyway because of the spacer you have added. Use the spring from the 1100 FD (one that slips on the pinion shaft) when re-assembling. It is slightly longer than the 750 spring, and it will shove the driveshaft forward nice and tight. HTH

[dbeardslee]

good thinkin', but...

...took the clip off as per the excellent instructions on the new website (nice work, bye the bye), and discarded it. I can feel the tip of the shaft enter the hole and it feels like the splines are lining up. I can rotate it with my hand and the u-joint moves along with it. It only seems to be going in the hole about 1/8 of an inch.

Here's the funny thing - it wasn't in there that awful tight when I removed it. I got it out by taking a piece of insulated copper wire and wrapping it once around the shaft behind the gear face. Gave a little tug and it popped right out. The only thing I can figure is maybe the u-joint wasn't perfectly inline with the shaft. Unfortunately my hands are way too big to stick any part of them in there by the u-joint to check it.

The way I aligned it was to adjust the height of the swing arm until I could see the entire end of the u-joint through the shaft housing. I then slid the shaft carefully in (kinda sounds like a B novel) until I felt it touch the u-joint. Then a little wiggling and I'm pretty sure I felt the splines mate-up. Pushed it in as far by hand as I could (which was almost nothing) tapped it a little more, rotated it to make sure I was in, put a 2 X 4 over it and whacked it. Net result - nothing. It stuck a little but I could pull it right back out with my fingers. Tried it about ten times that way, despite Einstein's definition of insanity. He was probably right.

[bikerphil]

boot

If you can't get your fingers in there to line up the u-joint, it's gonna be impossible. Try hooking a couple of bungee cords to the boot (mabye 2 or 3), and pull that friggin' boot towards the rear of the bike. Gotta get your fingers in there to line up the u-joint while looking up the swingarm tube with a flashlight. With the bike in neutral, you should be able to find the "sweet spot", where the u-joint is balanced so it is straight. Good luck, keep trying, you'll get it.

[dbeardslee]

Thanks Phil (and all). I hadn't thought about reaching through the boot. Might be able to get a finger or two in there that way. I'll give 'er a try.

[xschop]

assembly tip

The last one I did, I assembled the U-joint and drive shaft with the swingarm on the bench and then installed swingarm, then bolted u-joint to the Middle drive....JAT....chop

[dbeardslee]

Chop - I was hoping to avoid removing the swing arm, but if all else fails I'll give it a try. Since I've only got one other thing to try in my bag of tricks, all else may fail tomorrow morning The old girl beat me up too bad today and I had to retreat to the la-z-boy. Man, that Active On is good stuff.

[dbeardslee]

OK, so maybe prayer did work...

Chop - Can't thank you enough for your advice. I needed that little push. Took the gloves off this morning and removed the swing arm. Probably shouldn't have done that as now my hands are all greasy Anyway, here's what I discovered: The splines on the end of the u-joint yoke were totally ate-up.

I'm sure I caused some of the damage, but equally sure it was damaged to begin with due to the depth of the manglement. If I had managed to get that shaft to slide home with the spacer on it I would only have engaged about 1/4" of good spline. Pretty sure it would have failed.

I took my trusty dremel tool and cleaned up the splines enough for the shaft to slip easily into the yoke. There's plenty of spline for use with the original setup, but I'm going to have to replace the u-joint before I will be able to complete the 750 conversion.

Additionally, the swing arm bearings are looking a little rough. Still serviceable, but when I replace the u-joint they're going away too. I repacked them and reinstalled in the swing arm, and am about to put the whole thing back together.

Here's my advice to anyone doing the 750 FD conversion. Plan on removing the swing arm as it's the only way you can check the swing arm bearings, and makes access to the u-joint easier. Carefully inspect the end of the splines as once the conversion is done it's going to be less forgiving of chewed-up splines.

Thanks for all the great advice, folks. You saved my life - maybe literally.

[bikerphil]

750 FD tip

Do not use a BFH to install the driveshaft. Glad you got it figgered out, Dbeardslee. I got a few good extra u-joints layin' around if you need one.

[xschop]

Tech tip update

I have done 3 swaps personally and the very first one I did, I had to take a small-fine triangular file to all the U-joint splines because if you don't line up the splines very well then the Driveshaft is SO HARD of a metal that it will mushroom and smash the U-Joint splines at the tip if you take a hammer to the other end.....I have seen quite a few posts about this and think one of our XSellent moderators should add this addendum....Glad you got it squared away...Also cheching your swingarm bearings and adjustment is smart at this teardown stage...My 2 cnts......chop