Topic: Help! Rear wheel is drifting left - With Pictures!

[Bad Man]

You can see how the clevis on the bottom of the shock has been crushed. You're supposed to use a spacer in the clevis (a couple of washers works) along with a longer bolt, to keep that from happening. Detail.

Ah! So that explains it! I thought the cycle shop just threw some on. Would have been nice if they put in the proper washers.

Thank you MCRider! If you do get a photo of yours, I'd love to see it as a point of reference!

[MCRider]

You can see how the clevis on the bottom of the shock has been crushed. You're supposed to use a spacer in the clevis (a couple of washers works) along with a longer bolt, to keep that from happening. Detail.

Ah! So that explains it! I thought the cycle shop just threw some on. Would have been nice if they put in the proper washers.

Thank you MCRider! If you do get a photo of yours, I'd love to see it as a point of reference!

My spacer measures 5.2mm proud of the retainer. is yours? I'm using period S&W shocks on my project. Long springs. See my spacer? That's just a detail though and not your problem. The stock shocks clevis would fit tight on the swingarm with no spacer.

[MCRider]

In one picture it looks like your chain hits the shock. In another picture it looks clear.

If you look at the bottom of my shock you'll see the clevis is offset to the side. The CB750 shocks are left and right, the clevis is not symmetrical. I have a set of progressives but they are out of reach at the moment to confirm this, but I'm 99% sure of it.

Your shocks clevis is dead center on the bottom. If it was offset like mine it would kick the shock body away from the chain a bit.

[Bad Man]

In one picture it looks like your chain hits the shock. In another picture it looks clear.

It has always been a bit clear, my photography skills are even worse than my mechanic skills. 

I am thinking it was the chain guard (?) that was more of an issue (?)

Here is the chain guard:


Inside, the guard was pretty gouged.

I removed the Swingarm, I took pictures. The end caps were there, but not much else. Here are all the pieces that WERE there:

Side view:


I may be mistaken, but, it looks like I am missing my bushings completely. Wasn't I supposed to see felt rings ro rubber rings?

MCRider, thanks for that pic. Everyone's bikes look so pretty and clean! My rusty heap will get better!

[MCRider]

Where the chainguard was mashed up against the shock, that's where you'd notch it out with some sheet metal shears and hack saw. But it can become weak and crack over time. I think i have one that's been notched you can have for shipping.

The swingarm looks OK as far as the hard parts are concerned. Does the tube on the left (aka collar) fit nicely in the swingarm? If so then the bushings are in the arm OK. If it rattles around then the bushings may be missing but more likely very worn. Once they are in the swingarm they are very difficult to remove. The felt washers are nice to have but are for sealing out the water and don't do anything about the spacing.

On second look, there are some "top hat" end pieces that seem to be missing. they would account for several mm of play in the swingarm, side to side. But the wheel would be moving with the swingarm, so all those pieces, chain shock, guard, would maintain their relative position.

As to mine's cleanliness, it is a work in progress and after many years of flogging and abuse is being completely reconditioned, What you see has never seen the street.

[Bad Man]

Does the tube on the left (aka collar) fit nicely in the swingarm?

No, Sir, the collar falls out very easily. I ordered some bushings from here:
https://www.partsnmore.com/cat_index.php?model=cb750_sohc&category=chassis
I got part #28-1025

I am wondering if it was a combination of things, because it is looking less and less like it was any one thing in particular. When the chain threw, it was mashed between the sprocket, chain guard and shock so tight I had to take the rear wheel off to get it free.

I found an inexpensive set of stock shocks on eBay.

[MCRider]

Does the tube on the left (aka collar) fit nicely in the swingarm?

No, Sir, the collar falls out very easily. I ordered some bushings from here:
https://www.partsnmore.com/cat_index.php?model=cb750_sohc&category=chassis
I got part #28-1025

I am wondering if it was a combination of things, because it is looking less and less like it was any one thing in particular. When the chain threw, it was mashed between the sprocket, chain guard and shock so tight I had to take the rear wheel off to get it free.

I found an inexpensive set of stock shocks on eBay.

It should fall out side to side fairly easily. But when its in the arm it shold be snug radially. But if you're getting new bushings you're better off.

It'll be good to go when you're done.

[Bad Man]

Thank you for your outstanding input! I am now awaiting the delivery of some parts    I should have updates and photos by Sunday.

I also got that EvapoRust you recommended in another thread so I can clean up this bike a bit!

[Bad Man]

Well, got stock shocks on it now. New front and rear sprockets. New Swingarm bushings, rinsed out the tank with EvapoRust, treated the oil with seafoam and changed the oil afterward. IT is ready to go..... EXCEPT...

My dumb ass lost the bold and locking washer used to secure the front sprocket!!! WTF was I thinking?!?!   

AND

Some one ran into my bike, knocking it off it's center stand and cracking the clutch cover (?) as well as bending the side stand. Now it leaks oil when running, or when tilted sideways on its bent kickstand. Ugh.

Here is a picture of the leak... I am open to suggestions...   




This is the sprocket piece I am now missing:

[MCRider]

Man you're ....    You do have a 74 CB750 right?
Well that's the alternator cover, the clutch cover is on the right behind the kickstarter. Alternator covers are $$ tho if you start looking now you might find one for less, ebay etc.. I've got a chromed one that is scratched and the chrome is messed up but it doesn't leak, I'll let go for ... PM me.

That isn't anthing like what holds on the sprocket. Those two bolt holes in the sprocket itself is the holding point, along with a heavy splined washer hold down tab thingy.

The bolt you are pointing to was put there to seal off the chain oiler, which is what goes in that hole properly. Tho many plug it off, that's not the issue.

The issue is you don't have ANY of the hardware for holding the sprocket on. That sprocket is sitting way left of where it should be.

[Bad Man]

Thanks MCRider.... Yea... um... I meant "alternator cover".. 

Think I could braze this? It only leaks if it's running or sideways. I care nothing for the cosmetics of the bike, only the functionality.

Ranger- thank you for the link! Apparently I had been riding it the entire time with only that screw for the plug and a large washer! (anyone know what size screw that would be?

Last time I buy from a salvage yard!

[MCRider]

Thanks MCRider.... Yea... um... I meant "alternator cover".. 

Think I could braze this? It only leaks if it's running or sideways. I care nothing for the cosmetics of the bike, only the functionality.

Ranger- thank you for the link! Apparently I had been riding it the entire time with only that screw for the plug and a large washer! (anyone know what size screw that would be?

Last time I buy from a salvage yard!

Can you braze aluminum? I've never seen one repaired as it distorts and things are spinning in there. Could be done I suppose.

[Bad Man]

MCRider- that makes sense. I am just learning on the fly in an effort to have wheels, so I appreciate the knowledge you and everyone else has shared with me!

Thank you!

[Bad Man]

The issue is you don't have ANY of the hardware for holding the sprocket on. That sprocket is sitting way left of where it should be.

After re-reading this i realize it may have been part of the issue in the first place!

[2wheels]

Can you show a picture of the front sprocket area with the sprocket off so we can see the output shaft splines.
Here is a link to a 1978 which is what yours looks like.

http://www.ronniesmailorder.com/fiche_section_detail.asp?section=125285&category=MOTORCYCLES&make=HONDA&year=1978&fveh=2986

[Bad Man]

Can you show a picture of the front sprocket area with the sprocket off so we can see the output shaft splines.
Here is a link to a 1978 which is what yours looks like.

http://www.ronniesmailorder.com/fiche_section_detail.asp?section=125285&category=MOTORCYCLES&make=HONDA&year=1978&fveh=2986

I think this is where I find out that the bike is not the designation I thought it was. 


I checked the engine number: CB750E-3062628

[MCRider]

In my experience there should be a lot more shaft exposed, and that radial groove cut in the splines is where the splined hold on washer goes. The sprocket would sit completely to the right of that groove

I'm out of my league here, good luck. Others can help, I hope.

[2wheels]

Actually, this is how my 78 F looks.
The front sprocket it held up tight against the ridge shown in my picture.  Where my red arrow is.
The bolt with lock washer and large washer is what holds it up tight.
When installing this bolt I used Locktite (blue) thread locker.

[MCRider]

That's what it was looking like to me. But doesn't the 78 have a 630 chain? It appears tha Bad Man's is a 530 though that's from appearnaces and not confirmed. Certainly that sprocket he bot is an early model 530 sprocket.

[MCRider]

"I checked the engine number: CB750E-3062628"

OK that is a 1978/K8 number, which should have the 630 size chain. But the shaft and its hold down bolt is proper for the K8. Weird.

[GammaFlat]

Right - it's a K7/K8 setup to hold down the sprocket - which also gets you into more alignment issues..... let me do some poking around.  

[GammaFlat]

The 530 sprocket has a wider shoulder where it goes on the shaft but can be "bolted in place".  I believe others here have done it and I've been tempted when my K6 engine was down and I had a donor K7...  It might not be optimal because the sprocket has no lateral play like the K6 and prior but he K7 and K8 setup (even though the 630 sprocket has a narrower shoulder) is snug to the shaft as well.  I'm trying to recall which way but I believe the sprocket centerline is different between K7/K8 (630) compared to K6 and prior (530).

[MCRider]

The 530 sprocket has a wider shoulder where it goes on the shaft but can be "bolted in place".  I believe others here have done it and I've been tempted when my K6 engine was down and I had a donor K7...  It might not be optimal because the sprocket has no lateral play like the K6 and prior but he K7 and K8 setup (even though the 630 sprocket has a narrower shoulder) is snug to the shaft as well.  I'm trying to recall which way but I believe the sprocket centerline is different between K7/K8 (630) compared to K6 and prior (530).

There are or at least have been, aftermarket 530 sprockets that did not have the shoulder. But now that i think of it, using one of those would have led to alignment issues also, unless it was shimmed over. Hmmm.

But back to the OP problem... He's got two sprockets and a chain that seem to work. His front sprocket is on good, so what about the wheel to the left problem?...

[GammaFlat]

There is normally a very large fat washer holding down the sprocket on K7/K8 that appears to be missing in this case.  Also, since there is no automatic oiling system, it would be prudent to lubricate the 530 frequently.  The 630 setup did not require as much maintenance and therefore had no oiler (guessing a little here).  

I just did an "unscientific" measurement of the centerlines of the sprockets.  It appears to me that the sprocket centerlines are different by almost 1/4 inch.  The K8 engine will have a more "outboard" positioning of the sprocket.  This is increased slightly because the overall width of the shoulder on the 530 sprocket is greater.  

[GammaFlat]

What size is the rear wheel? (sorry if this was covered)  And more importantly which carrier is he using?  I believe the sprocket carriers are interchangeable and there is a marked difference between K0-K6 and K7/K8.  Cyclexchange has a picture of this - lemme dig for it.