Author Topic: Worn swing-arm collar - 75 cb750f (Read 3773 times)

Kickstart · « **on:** July 12, 2011, 10:36:23 PM »

I didn't do my homework and thoroughly search this site before diving into my swing-arm bushing replacement. If I did, I would have known that the collar is usually worn past it's serviceable limit.

I get everything apart, and it looks like my collar is shot (see attachments)

I measured it with my mic that I bought on ebay 15 years ago, which I never had adjusted, nor really know how to use, so I'm not sure how accurate my measurement is. But if my measurement is correct then I'm out of spec per the shop manual (manual states 0.8452 in)

I've got the new "Parts+Plus" bushing... which look nice (with internal grease grooves!), but I assume putting everything back together would be a waste at this point, as I would probably have too much play.... Is this correct, or can I get away with using the old collar?

Any suggestions on what to do now? I was hoping I wouldn't have to do a full-out older style collar conversion on this bike. I was also hoping this wouldn't take more than a week before I got back on the road.

Bodi · « **Reply #1 on:** July 13, 2011, 04:13:00 AM »

Contact Hondaman. He was servicing swingarm pivots and may still do it. I've heard only good about his work on these. You send the entire swingarm, collar, maybe even the bolt and caps. It comes back working properly with bronze bushings.

MCRider · « **Reply #2 on:** July 13, 2011, 06:46:36 AM »

You can put it back together and it will likely work better than it did. Was it seized up before? Once a steel part seizes to its counterpart I don't think you can ever really refurbish it to new. I would use a fine strap of emery paper and shoeshine it as best as possible to get the seized material off. Then use the new bushings. Driving in the new bushings will often distort them and without a proper ream, you'll be driving the collar back in as well. Freeze the bushigns and heat the swingarm may help.

I had mine done by Hondaman, per Bodi. He would use a new collar, checks the swingarm for roundness and corrects if necessary, and makes the bushings of oillite bronze (?) to match the collar, reams them to within spec, uses special design to get the lube in where it needs to be, (both need to be grooved to carry the grease where it should go) oversize zerts, etc. See "services offered" forum. Guaranteed for life.

But the turnaround may not suit. If you need quick, do what I said, do the best you can and go ride. Upgrade later.

Kickstart · « **Reply #3 on:** July 13, 2011, 09:08:01 AM »

It wasn't seized up. I was actually able to push the collar out part-way with my finger, and then pull it out the other side by hand.

I was just doing a suspension tune-up: I replaced the front steering bearings (with tapered), new progressive front fork springs, and have Ikon rear shocks arriving soon.... and figured I would replace the swing-arm bushings as well (not realizing there was a high probability the collar would be worn past the service limit, and no longer available - so I didn't plan appropriately).

I do have a Hondaman swing-arm on my wishlist (as well as an ignition unit) when I rebuild my other bike, but I was hoping to get away with just replacing the bushings on this bike. Maybe I'll pull the collar out of the other bike to see if it's in better shape (doubtful as it has around the same mileage on it.)

I didn't even think about having to ream the new bushings. I'll try freezing the bushings / heating the swing-arm. Hopefully everything will go together without too much trouble.

Thanks

Johnie · « **Reply #4 on:** July 13, 2011, 09:17:12 AM »

So just how much play is allowable in the swing arm? I can move my K1 back and forth a little...is that allowable? Miles on the bike is about 30,000 and would not think they could be worn yet.

bryanj · « **Reply #5 on:** July 13, 2011, 09:21:56 AM »

You can put the pivot in the opposite way round to that which it came out with the wear at the bottom instead of horizontal and pump with grease every week or max 1,000 miles. That will last for quite a while till you can get it done properly.

Jonnie 30,000 is about it from original when not greased often enough, supposed to be every 1,500 service but weekly is better

MCRider · « **Reply #6 on:** July 13, 2011, 09:26:29 AM »

Quote from: Johnie on July 13, 2011, 09:17:12 AM

So just how much play is allowable in the swing arm? I can move my K1 back and forth a little...is that allowable? Miles on the bike is about 30,000 and would not think they could be worn yet.

Oh yeah, worn or seized, you're overdue for inspection replacement. IMO ASsuming they haven't been looked at.

30K is enough for them to be worn. 40 years is enough for them to be seized.

AS to how much, with the pivot tightened to spec, and the lower shock mounts removed, it should be only the very slightest of nearly imperceptible movement. A new, of fresh, set up would have no movement perceptible. (Having the lower shock mounts tight can mask the movement.)

Johnie · « **Reply #7 on:** July 13, 2011, 09:33:50 AM »

Excellent info...correct, with my lower shock bolt tight I still have what I think is a lot of play, especially compared to my KO and K4 which don't move. I better think about doing it soon. Do I need special tools and a press to do this. Have not done a swing arm yet. The K1 has the grease zerks on both ends. One last question...should I buy them from Honda or are you saying Hondaman has something better? I apologize for the hijack...it just caught my eye.

MCRider · « **Reply #8 on:** July 13, 2011, 09:55:33 AM »

Quote from: Johnie on July 13, 2011, 09:33:50 AM

Excellent info...correct, with my lower shock bolt tight I still have what I think is a lot of play, especially compared to my KO and K4 which don't move. I better think about doing it soon. Do I need special tools and a press to do this. Have not done a swing arm yet. The K1 has the grease zerks on both ends. One last question...should I buy them from Honda or are you saying Hondaman has something better? I apologize for the hijack...it just caught my eye.

here is the link: http://forums.sohc4.net/index.php?topic=58828.0

Most recent post May 2011, so he must still be doing it. PM him (HondaMan aka Mark) for details. He makes his own bushings to fit your swingarm and collar. They are sized AFTER installation, to close tolerances, no warping or oblonging.

You can DIY. A lot of struggle and bloody knuckles. I've done 2. After having Mark do the last one, never again DIY. Just removing your swingarm to ship out will give you an idea of what you're up against, once you can see the collar and bushings are likely worn out and seized. You'd need hack saw to cut the old bushings out, a BFH Hammer and various drifts. A press helps, but can also hurt.

willbird · « **Reply #9 on:** July 13, 2011, 09:56:00 AM »

You can check a 0-1" micrometer by running it closed on a sheet of paper, pull the paper out to clean the faces (zig zags work great for this)..then gently run it closed, it should read 0.

Bill

Johnie · « **Reply #10 on:** July 13, 2011, 09:59:53 AM »

Thanks MC I will contact Hondaman. I think I would rather send the arm to him.

MCRider · « **Reply #11 on:** July 13, 2011, 10:06:48 AM »

On your K0 and K4, they are likely seized, though not worn. The seizing occurs between the collar (odd name for that part) and the bushings. The bushings then begin to turn in the swingarm tube itself, masking the condition. Yuk

A fresh set up is soooo nice, and that's just from my experience doing it myself. Can't wait to ride on the HondaMan set up.

bryanj · « **Reply #12 on:** July 16, 2011, 07:17:39 AM »

Replaced more than i care to talk about but only with Honda parts and always the collar and bushes together, sometimes easy often a real pain and this was when the bikes were new enough not to have worn the swing arm which is the main reason for sending to Mark

Johnie · « **Reply #13 on:** July 16, 2011, 07:28:54 AM »

I sent my K1 swingarm to Hondaman (Mark) on Friday. Looking forward to the feel of new bushings. May end up sending him my KO & K4 arm in the future.

Kickstart · « **Reply #14 on:** July 16, 2011, 09:01:30 AM »

Everything went back together pretty easy.

Thanks MCRider for the recommendation on heating the swingarm.

I cleaned up the collar ends with 00 steel wool, and then rinsed with carb cleaner. I also lightly sanded the ID of the swing-arm with wet/dry sandpaper to clean-up some scratches I made when removing the old bushings.

I put both the new bushings and old collar in the freezer for about an hour. And then I "baked" the swing arm in the oven for 20 minutes at 170F - yes the wife was out of the house

I pulled the swingarm out of the oven, greased the ID, grabbed the new bushings out of the freezer, put a quick coat of grease on them as well, and they easily tapped in with light taps from a wood block. One of them did require more force after going half-way in, but I believe that was because of bump/score I made with the screwdriver when removing the old bushing (that I wasn't able to sand down all the way.)

Nice thing about heating up the swingarm, was once I got the new bushings in, they absorbed the heat from the swingarm and got pretty warm themselves. I then grabbed the old collar out of the freezer, generously applied grease, and it slid in with no problems (completely by hand).

Bolted everything back on - and so far so good. (I'll to a test rider later today.)

BTW, how does one measure swingarm play? I assume you have to unbolt the bottom of the shocks and loosen the chain. Even with just the swingarm on (no shocks or wheel) I couldn't really noticed any play (after putting the new bushings in). Not that it had any noticeable play before I replaced the bushings - I did this as more of a suspension tune-up measure.

I'm happy I did this maintenance, but all said, I'll be sending the next one to Hondaman as well.

CycleRanger · « **Reply #15 on:** July 16, 2011, 09:08:33 AM »

Check the swingarm bolt for straightness.
Mine was bent.
The first replacement I got was bent as well. The next one was straight.

Ira · « **Reply #16 on:** March 19, 2012, 07:39:32 AM »

Topping this thread because I'm in a similar situation. The collar on my '77 750K was seized and i had to drive it out. I cleaned it up and it looks pretty ugly- pitted and discolored.

I have aftermarket bronze bushings, which i'll be installing this week. I'm worried though, because if I slide the bushings onto the collar (uninstalled), it's not a smooth fit- there's a little play.

I noticed a few people alluding to the bushings compressing slightly when installed, but is that true? Should I expect the tolerances to change that much?

If I put this back together, am I throwing good money after bad, so to speak? Will the worn collar damage the new bushings?

Milkman666 · « **Reply #17 on:** March 19, 2012, 10:00:53 AM »

Hey Ira,

That one looks pretty nasty to me. It looks as though it was not greased for a long while, and maybe seized for a while. I'd measure it at least, but I think I'd be looking for a new one.

Using the Hondaman Bible as a guide, I cut grooves into my 750F collar myself and got new bushings etc., so if you can't find one of the old style collars, get a newer one and fire up your Dremel.

One thing I'd check though... make sure the swingarm tube is still round(ish) and in good condition.

Ira · « **Reply #18 on:** March 19, 2012, 10:09:51 AM »

Do you know if the old-style collar (which it looks like I could purchase OEM) will work with the 77-78 bushings ("top hat" style) or should I return them and order the old-style bushings for my 77 swingarm?

Ira · « **Reply #19 on:** March 19, 2012, 10:34:17 AM »

Actually, never mind the last question, I think this explains it:

Quote from: HondaMan on February 14, 2009, 12:54:37 PM

...All of the bushings are interchangeable size-wise, and the older style holes-and-grooves collars (like in your pictures) will work with ALL years and models of the SOHC4s...

http://forums.sohc4.net/index.php?topic=46432.0

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Author Topic: Worn swing-arm collar - 75 cb750f (Read 3773 times)