installing a swingarm w/ drive box in a Tonti frame

[Rusnak_322]

Is this possible?

Do I need to remove the drive box to ease installation?

I have been looking at the G5 workshop manual from thisoldtractor.com and it looks like it is supposed to be installed as a unit. But I have been having issues getting it to line up. the swingarm is very tight to the frame. So much so, that I had to scrape off the new paint on the frame (it wasn't that thick). and I still have a hard time getting into place. I can get one side in (opposite of the drive box) but then the thing is cocked and I cant get the other side in.

Plus, it seems like it is ridiculously difficult to line up the driveshaft splines to the motor and the assembly is pretty heavy.

Also, by looking at the service manual I cannot tell if I were to remove the drive box, will I have to drain the gear oil and then re-shim when I put it back together?

[rodekyll]

Take off the drive.  You need to be able to turn the drive shaft to align the splines.

Then llook at the frame where you are putting the forward end of the swing arm.  The are slots in the frame.  If you angle the tail downward the pivot tube slips up those slots and into position very naturally.

Some folks remove the lower of thos frame bolts holding the rear of the bottom rails on to help with the space problem.  Inserting should be a 30sec operation when that  downangle is right and the slots are used.

Remember that the swing arm needs to be properly aligned or you sideload your u-joints.

[Rusnak_322]

thanks,
Will I need to drain the box prior to removing it?

I did unbolt the lower frame rails, I thought they were pulling the frame in (they weren't)

[wymple]

I got mine on. The coupling on the shaft, and pressed up as far as I could go did not want to line up to slide on. Pull the plug wires to kill the ignition and bump the starter for the rotation necessary. Popped right in. I fought with it for an hour before giving up and doing that.

[Rusnak_322]

unfortunately, I have a little way to go before I start hitting the starter button. 

[Wayne Orwig]

Take off the drive. Keep the splined end pointing up and you won't lose any fluid.
You need to lube the splines in there anyway.

[nc43bsa]

I'll be doing that this week.

What is the preferred spline lube?

[Two Checks]

I use CV joint grease or Moly Lube.

[v7john]

Take the drive box off. The reduced weight makes it easier to get the swing arm on and the UJ splines lined up.

Remember when refitting the drive box to leave fully tightening the 4 nuts holding it to the swing arm till the rear wheel axle has been lined up.

[Rich A]

I'll be doing that this week.

What is the preferred spline lube?

Someone, I think MG Cycle, sells the stuff. Sticky as snot.

Rich A

[Rusnak_322]

Take the drive box off. The reduced weight makes it easier to get the swing arm on and the UJ splines lined up.

Remember when refitting the drive box to leave fully tightening the 4 nuts holding it to the swing arm till the rear wheel axle has been lined up.

I just read up on this today. Good tip. Make sure the rear axel slides out without any resistance when the bolts are tight.

[Antietam Classic Cycle]

What is the preferred spline lube?

Like many things, everyone has their own preference. This is mine:

[Rusnak_322]

Got it in, had a hard time getting it off the swingarm, the bearing box part stayed with the swingarm.
Now I have to find the article with the tips about adjusting the swing arm stub spindles that I came across last week but forgot to bookmark.

[fotoguzzi]

Got it in, had a hard time getting it off the swingarm, the bearing box part stayed with the swingarm.
Now I have to find the article with the tips about adjusting the swing arm stub spindles that I came across last week but forgot to bookmark.

just count the exposed threads on the pivot pins and make them equal.. I'm more worried about the "bearing box", so the the pinion gear came out of the rear drive? it needs to be sync'd proper to the crown gear.. right Pete?

[Tom]

 :1: on all the advice given. 

[Rusnak_322]

just count the exposed threads on the pivot pins and make them equal.. I'm more worried about the "bearing box", so the the pinion gear came out of the rear drive? it needs to be sync'd proper to the crown gear.. right Pete?

are you talking about setting the crown / piston clearance?  - like on page 94 of the pdf (page 92 of the service manual)

http://www.thisoldtractor.com/mg_manuals/workshop_manual_g5_sp.pdf

I wouldn't think that it was altered by removing the bearing box

[fotoguzzi]

maybe but I'm unsure what the "bearing box" is in your post.

[twhitaker]

I wouldn't think that it was altered by removing the bearing box

True.

[oldbike54]

 I am also curious what a "bearing box" is .

 Dusty

[twhitaker]

I think it's the part that houses the pinion and bearings.

[Rusnak_322]

Sorry, this is my second bike with a shaft drive (I also have a PW50)

I confused Drive Box and Bearing housing. What I am talking about is "E" below.

[Chuck in Indiana]

are you talking about setting the crown / piston clearance?  - like on page 94 of the pdf (page 92 of the service manual)

http://www.thisoldtractor.com/mg_manuals/workshop_manual_g5_sp.pdf

I wouldn't think that it was altered by removing the bearing box

No, he's talking about the swing arm bearing pins.

[Wayne Orwig]

Sorry, this is my second bike with a shaft drive (I also have a PW50)

I confused Drive Box and Bearing housing. What I am talking about is "E" below.

If the pinion assembly (E) stayed on the swingarm, That means it likely IS rusted to the driveshaft and coupler. Try to get it off of there and gooped up to save the splines.

On the swingarm pins, just count the threads on each side. Turn them in to remove all play.

[Rusnak_322]

If the pinion assembly (E) stayed on the swingarm, That means it likely IS rusted to the driveshaft and coupler. Try to get it off of there and gooped up to save the splines.

On the swingarm pins, just count the threads on each side. Turn them in to remove all play.

It came off with the swingarm, but I was able to get it to move about 1/16". After it came off, I didn't see any reason to pull it off.

I don't think that anything on this bike is rusted. The back story of this bike (from the seller) is that a older Guzzi enthusiast had a stroke and put this bike together with spare parts he had as a kind of physical therapy. The guy I bought it off, got it from his estate. He only wanted to buy one of the bikes, a Ducati, but the family wanted to sell the duck with two Moto Guzzi's as a set. The other Guzzi was a race bike. I wonder if he was a member here at one time??

I have never had a bike come apart so easy, and I used to take 1 year old street bikes and turn them into race bikes! I bet that there was 4 lbs of copper never seize on here. Everything with threads seems to have it, except the 4 bolts coming out of the drive box, they have what looks like blue loc-tight.

[rodekyll]

There are O-rings at either side if the bearing carrier.  Also, the carrier has only one correct orientation when you reinstall it.  Don't get it wrong.

I may be overpicky about the swingarm alignment, but if you thin so, I don't want to hear about it.  this is my swingarm alignment method:

screw in the pivot pins and check them with the depth post on your dial indicator.  If you don't have a dial indicator --- PULEEZE!  Tweak until they are exact AND the swingarm binds (doesn't drop freely).  Then a slight turn back -- just a nudge -- on both pins until the swingarm drops freely from any angle but has no 'looseness' when you rattle it -- much like setting up a steering head.

As I've said before, sideloading the ujoint causes premature wear of all sorts of things like the ujoints, carrier and tranny shaft bearings, etc.  So I take it very seriously.  ymmv, and/or some folks don't care. $0.02, etc.

[Chuck in Indiana]

I use depth mics. Don't have depth mics? PULEEZE! 
But I take it seriously, too, although I think a guy with a good eye, 10X magnifier and machinist's scale could get it close enough.

[mtiberio]

side to side equality is not critical on a big block guzzi with a double (CV) u-joint. On small blocks with their single knuckle joints, yes, the output shaft must be co-planar with the driveshaft. On big blocks, you can use the swingarm pins to move the swingarm right or left as needed. When I raced, I offset the rear wheel to the left (relative to the rear drive unit) so that fatter tires wouldn't rub against the swingarm. To bring the tire back into alignment with the front, I would then shift the whole swingarm to the right via the swing arm pins.

assuming that equal amounts of the swing arm pins showing means that the output shaft and driveshaft are co-planar is a big assumption.

[Rusnak_322]

side to side equality is not critical on a big block guzzi with a double (CV) u-joint. On small blocks with their single knuckle joints, yes, the output shaft must be co-planar with the driveshaft. On big blocks, you can use the swingarm pins to move the swingarm right or left as needed. When I raced, I offset the rear wheel to the left (relative to the rear drive unit) so that fatter tires wouldn't rub against the swingarm. To bring the tire back into alignment with the front, I would then shift the whole swingarm to the right via the swing arm pins.

assuming that equal amounts of the swing arm pins showing means that the output shaft and driveshaft are co-planar is a big assumption.

When you say you offset the rear wheel to the left, do you mean that when you built the spoked wheel that you purposely offset the rim from the hub? OR did you use a spacer?

[Chuck in Indiana]

assuming that equal amounts of the swing arm pins showing means that the output shaft and driveshaft are co-planar is a big assumption.

Agreed. After all the frame is just a big weldment with all the warping that involves. Still.. I try to do the best I can to center it.

[John A]

When you put the rear drive assembly on, tighten the axel before tightening the four nuts on the front of the pinion housing. It's in the manual to do it that way,case you doubt it