Topic: How do I know if my swingarm bushings are bad?

[Rgconner]

Is there a way to test them short of pulling them?

[Bankerdanny]

If you remove the rear wheel and shocks can you move the arm up and down? Can you wiggle the arm from side to side (have a friend around when you test this so the bike doesn't fall on you).

If the arm moves properly up and down with minimal effort and there is no slop in the fitment on the shaft, then I would say the bushings are fine.

[Gordon]

If they're worn badly enough you don't even have to remove the wheel or shocks to tell.  Just put the bike on the center stand and try moving the wheel back and forth sideways.  Before I got the Hondaman swing-arm rebuild I could move the rear wheel on my K1 back and forth at least a quarter of an inch. 

[Johnie]

Gosh Gordon a quarter of an inch...yikes. I just got mine back from Hondaman. He did my K1 for me and I had not quite a quarter inch, but with the wheel and shocks on it was close. I would imagine that if I took those shocks and wheel off it would have been much worse. Got it all put back together yesterday and took a 125 mile ride. All is well...

[Gordon]

Gosh Gordon a quarter of an inch...yikes. I just got mine back from Hondaman. He did my K1 for me and I had not quite a quarter inch, but with the wheel and shocks on it was close. I would imagine that if I took those shocks and wheel off it would have been much worse. Got it all put back together yesterday and took a 125 mile ride. All is well...

It was bad enough shortly before getting it rebuilt that in corners I could feel the back end shift from side to side.  I had gotten used to the way it felt so the difference in feel and confidence when cornering with the new bushings was amazing! 

[Johnie]

Agreed...I was coming into my driveway and felt a strange sensation in the back of the bike. That was how I found mine.

[Spanner 1]

I bet a good 1/2 of our SOHC's on the road everyday have 'shot' bushings.... especially on the chain side.... the effect is clunkier shifting, chain snatching and rear wheel 'lag' in corners....
The best test of your swingarm IMO is to deliberately ride along a road 'tar' joint trying your best to stay in the joint. If yor scared within the first 10 secs. = your swingarm bushings are shot 

[MCRider]

besides all that's been said so far, if the bike has any age to it, and ours do, the bushings seize to the "collar". Then they begin turning in the swingarm tube itself, not good.

The origianl design can be made good, by careful assembly with the right parts ala HM, but the OEM materials and execution preclude any bikes from functioning properly.

To answer the question: If they are over 30 years old (and they are) they are shot.

OCICBW but I don't think so.

[Spanner 1]

AND....... the only solution to a rounded-out chain side bushing is Hondaman's solution; i. e. custom fit the bushing to the arm and shaft .......... aftermarket bronze bushings will last about 1,000 miles ( ask me how I know ! ).

[Rgconner]

Thanks guys.

Yeah, they are shot. somewhere over a 1/4 movement, but not a half inch.

What aftermarkets can I try before sending it to HM?

Not that I would not like to do it.. but... I just bought his ignition + coils and am not able to plunk down that much dough for a while.

[HondaMan]

Thanks guys.

Yeah, they are shot. somewhere over a 1/4 movement, but not a half inch.

What aftermarkets can I try before sending it to HM?

Not that I would not like to do it.. but... I just bought his ignition + coils and am not able to plunk down that much dough for a while.

I'm sorry to say that about 25% of the arms I see had the attempted aftermarket bushings installed, which didn't work. Time was, there were companies that made good ones: this seems to be gone. That's how I got into the rebuild thing with them. These arms have no less than 4 different ID sizes in the 750 alone: that's why most of the aftermarket solutions don't seem to fit, I suppose. The same bushings are being sold for the CB350F and CB400F, CB750, CB500/550, and CB450. There are 12 different sizes in reality, for these bikes: 4 for 750, 2 for CB350F, 2 for CB550, 2 for CB450, 1 each for 500 and 400F.

[Gordon]

Not that I would not like to do it.. but... I just bought his ignition + coils and am not able to plunk down that much dough for a while.

Tighten the belt for a little while and save up.  It's worth it!

[kajtek]

damn, all the symptoms described i have on my 400 4. will stick it on the stand today to check out the wear.

so just to confirm, that if my bushings are worn, and i replace them with the OEM ones, its not going to be any good?

its not practical for me to send my swingarm to hondaman for rebuild, im in the uk, bikes a daily rider and i cant afford it at the moment. whats the best i can do to give myself as solid and stable a swingarm joint given my circumstances?

i have seen bronze bushings listed for the 400 4 specifically, can i give it a go with these?

thanks

ashley

[dave500]

years ago i tagged along with a mate of a mate who wanted to buy a dirt bike,after speaking to the owner the first thing i did was crouch down,grab the rear wheel and swing arm with both hands and shake it to death,, the owner says something like hey carefull,,im thinking your a knob,as if itll break?what i said to him was this is pretty #$%*ed out man,,,it was all worn out badly and too obvious,,the whole bike was junk anyway,on the way home the mate of the mate says to me i wish i took you along before,,you tear em to shreds,,he would have bought that bike otherwise.

[HondaMan]

damn, all the symptoms described i have on my 400 4. will stick it on the stand today to check out the wear.

so just to confirm, that if my bushings are worn, and i replace them with the OEM ones, its not going to be any good?

its not practical for me to send my swingarm to hondaman for rebuild, im in the uk, bikes a daily rider and i cant afford it at the moment. whats the best i can do to give myself as solid and stable a swingarm joint given my circumstances?

i have seen bronze bushings listed for the 400 4 specifically, can i give it a go with these?

thanks

ashley

The main problem is that Honda has changed the material of their replacement bushings to be powdered steel composite. This makes a steel-on-steel bearing, which is impossible to lubricate. (Even the Machinery's Handbook, bible of automation machinery, says to NEVER make this combination). It's a mystery why Honda has done this, but it sure has kept my lathe busy with repairing torn-up swingarms from those steel bushings.

If you have a machinist friend, you could have him make you some bronze bushings and could install them with pretty good results. He has to be smart about it, as the holes in the swingarm are often now tapered wider toward the outside ends, so he may have to taper the bushings, too (more than 50% of the ones I make are like this).

Here's the specs he needs for a CB400F:

Length: 1.70"
Installed Clearance to collar: 0.0008" to 0.0012"
Interference fit to ID of swingarm: 0.0006" to 0.0008"
Material: 841 Oilite Bronze or SAE660 bearing bronze
Bearing should be straight, not flanged, and recessed 0.210" into the swingarm tube.

You will also need:
2 each end caps (Honda calls them a "bush"), #52109-283-300
2 each felt washer seal #52145-283-000

These parts will comprise a watertight, grease-holding seal like the early 750 had, greatly extending the life of the system. Look at a parts diagram for the 750 swingarm (1969-1974) to see how the parts will assemble.

Finally, make SURE the grease can reach the bearings. Using Oilite will help when you forget for a while, but not forever. The grease fittings and involved clearance must feed the grease all the way out to the seals when you reassemble everything. Here in the USA I ad the North American grease zerks, far superior to the old Japanese types, because grease can easily be forced through the system that way.

[kajtek]

damn, all the symptoms described i have on my 400 4. will stick it on the stand today to check out the wear.


so just to confirm, that if my bushings are worn, and i replace them with the OEM ones, its not going to be any good?

its not practical for me to send my swingarm to hondaman for rebuild, im in the uk, bikes a daily rider and i cant afford it at the moment. whats the best i can do to give myself as solid and stable a swingarm joint given my circumstances?

i have seen bronze bushings listed for the 400 4 specifically, can i give it a go with these?

thanks

ashley

The main problem is that Honda has changed the material of their replacement bushings to be powdered steel composite. This makes a steel-on-steel bearing, which is impossible to lubricate. (Even the Machinery's Handbook, bible of automation machinery, says to NEVER make this combination). It's a mystery why Honda has done this, but it sure has kept my lathe busy with repairing torn-up swingarms from those steel bushings.

If you have a machinist friend, you could have him make you some bronze bushings and could install them with pretty good results. He has to be smart about it, as the holes in the swingarm are often now tapered wider toward the outside ends, so he may have to taper the bushings, too (more than 50% of the ones I make are like this).

Here's the specs he needs for a CB400F:

Length: 1.70"
Installed Clearance to collar: 0.0008" to 0.0012"
Interference fit to ID of swingarm: 0.0006" to 0.0008"
Material: 841 Oilite Bronze or SAE660 bearing bronze
Bearing should be straight, not flanged, and recessed 0.210" into the swingarm tube.

You will also need:
2 each end caps (Honda calls them a "bush"), #52109-283-300
2 each felt washer seal #52145-283-000

These parts will comprise a watertight, grease-holding seal like the early 750 had, greatly extending the life of the system. Look at a parts diagram for the 750 swingarm (1969-1974) to see how the parts will assemble.

Finally, make SURE the grease can reach the bearings. Using Oilite will help when you forget for a while, but not forever. The grease fittings and involved clearance must feed the grease all the way out to the seals when you reassemble everything. Here in the USA I ad the North American grease zerks, far superior to the old Japanese types, because grease can easily be forced through the system that way.

thank you very much for all the detailed information, its of great help! that is crazy regarding honda's change in materials for the bushing, i can only assume that a bushing from another manufacturer/bike is not available that would fit.

i dont have a machinist friend, but i live in a town with a lot of small businesses and helpful people so im going to ask around and see what i can work out, as what you have described is way beyond anything i could do!

ashley

[Rgconner]

3 hrs or so of cutting and pounding and the old ones came out.

New brass bushings are in, and the rear tire does not move a millimeter. Very, very nice.

Still working on the head and carbs, so no idea when I will get to really test it. Right now I am a rolling chassis.

[DJ_AX]

Replaced mine a few/several thousand miles ago...
With the available cheap ones.
Was tight then...
now I've got a little play.
 
Winters only a few months away...
I ..... may be getting some HondaMan bushings along with some of the other HondaMan stuff.