750 Final Drive enigma

[MAXIMAN]

Chop

When I pulled mine I had about 5000 on it. Obviously the "Feels about right" torque method is not kosher unless ya get lucky. Proving once again I'm not a lucky man.

[pggg]

Good ole Patricks lips are sealed...

[MAXIMAN]

Ok smellers ...eh er fellers... here's the gig. I disassembled my "first" 750 Drive. The pinion retainer nut was loose...I mean HANDY type loose.

MY BAD! I simply did not torque it to spec and that is why the entire drive coupling was loosey goosey. Due to the slack it chipped one of my pinion teeth. That was the chip I saw on my magnetic plug.

No one else has had this problem probably because they actually tightened their pinion nut!

Won't happen again. I got the torque exactly on the money and the bearing pre-load was right at 4 - 4.5 inch-pounds as per spec for the type two drive.

PS: It would be a good idea to use lok-tite on the threads when re-installing the pinion retainer nut.

[mro]

Good ole Patricks lips are sealed ... .....

Gotta be a first.
pgg probably just got his fingers stuck together
from using to much duck tape and is having trouble typing....


mro
btw, been watching this thread.
Might like to mod one of my specials some day.

[Rubin]

I must have the worst luck in maintaining my bike. I received my replacement drive shaft and middle drive gear on Monday, and I have spent so far 3 hours trying to put it together. It seems I cannot get the drive shaft to seat properly in the yoke. I am holding the U joint with one hand and trying to insert the shaft with the other. I can get it so it catches, but I cannot get it to fully seat. I have tried to press it in with clamps and I have tried a BFH (rubber). No luck yet. Any tips I could try to get this to insert easier? Is it really this hard to do or am I as inept as I think I am???

[MAXIMAN]

Originally posted by mro
Good ole Patricks lips are sealed ... .....

Gotta be a first.

Rubin...are you sure you are using the Eleven shaft and not trying to seat the 750/850 shaft in the yoke?

Also...when I did mine I had a friend hold the yoke centered in the shaft housing while I stabbed it on the other end. The first one I did seated on the first try. The second one I did took a good 20 minutes of clouding the air with profanity before it seated.

[Rubin]

It is the XJ replacement shaft. I measured the two and they are the same length and what not. If it is just a matter of shoving it in, perhaps I have just had bad luck so far and will continue to try it. I suppose I could remove the middle gear a little to get a better look at what I am doing due to lack of space, but I really don't want to do that unless I need to. The splines on the original shaft on the middle gear end were perfect so there should be no wear on that part. I tried to insert the original shaft with the same results. Perhaps I have something blocking it or I am just not aligning it correctly.

So close to getting back on the road, yet so far!!!!

[mro]

I've only had a few shafts in/out, and beyond normal trouble getting it aligned went right in.

Would look closely at end of shaft. Sounds like you tried installing with a bit of force and if there's an issue may find a mark (or galling) in the metal.

Off the wall thought, did you grease the splines? Could there be too much stuck up in the female end keeping it from going in all the way?


mro

[xschop]

c-ring

make sure that c-ring around the Drive shaft splines is off (you don't need it)

[Rubin]

There must be something preventing me from getting it to fit correctly. The circle clip is off, so there is nothing ion the shaft causing the problem. I think I need to get a closer look at the socket to see if there is a problem on that end. Thanks for the thoughts guys!

[Rubin]

Well, I dropped the swingarm and checked the U joint. There was definitely some damage there but just to the outside of the splines - kind of like cross threaded. This could very well have been me in my attempts to reinstall the shaft, but it would have gone in easy if it was fine the first time. Needless to say, I aligned the best threads on the bottom and gently placed the shaft in the threads. A small tap with a hammer helped it cross the bad area and it seated well. I tried it with the swingarm partially attached and I was able to repeat my first attempt. Once I figured this out, it took me about an hour to put the bike back together.

I must say chop, this was a brilliant discovery!!! She just seemed to settle down while riding, very smooth throughout. I did not push it yet, going to recheck everything in about 1000 km or so to ensure I tightened everything down correctly. This was easier than I was expecting, especially if you did not have to replace your driveshaft as I did. I think I will start looking for a replacement U-joint and repair it when it needs servicing next.

Thanks again for all the help, your tips and suggestions were all right on the money!!

Cheers, I am back on the road!!!

[jurgenkoppen]

Just did my FD, modified the modification

Gentlemen,

thank you so much for this discussion and the idea. I just completed my 1980 XS, using a $65 Ebay aquired XS850 FD.
Here is what I came up with to avoid loosening the pinion nut and causing all kinds of uncertainty with proper torque upon reassembly:
I took my 850 FD, cleaned the area around the spooge holes thoroughly with carb cleaner.
I filled the holes with gasket sealant, and once set , I proceeded to mix up a small amount ( 10ml) of very liquid epoxy. Not the stuff from the tube, but the stuff you can get in marine supply stores to do epoxy repairs on boats. I used a syringe to squirt it around the washer, build it up to about the height of the washer (Base of pinion nut)
Voila, holes sealed with a full seized washer poured in situ. No need to dis- assemble the critical parts.
The rest was a breeze, done in 1.5 hours.
Awesome, the change. Now the bike is geared the way I like it.
Thanks again to the inventor and promoter of this mod.
Jürgen

[MAXIMAN]

Jurgen

That's XSactly what CHop did initially. It has worked fine for him.

I just wanted the extra measure of security by installing the larger washer to cover the holes.

Once I got the drive manual and learned the proper procedure for tightening the pinion nut and determining the bearing pre-load there has been no problems.

Several other members have done same with the larger washer and proper torque with no reported problems.

YMMV

Cg