Author Topic: DOHC CB750 swingarm in a K1 (Read 19231 times)

Industrial Cafe · « **on:** February 13, 2009, 03:41:55 PM »

I cannot get the needle bearings out of my 80 dohc swingarm.
The plan is to cut about 0.5in out of the one side and reinstall them deeper in the swingarm, so I can put it on my k1.

help!

mattcb350f · « **Reply #1 on:** February 13, 2009, 04:02:39 PM »

I think if anything, you have to cut the same amount of each side. Otherwise, you through off yer alignment...which you'll find out rather quickly after it's back together.

Does it need to be narrower to fit in the frame?

Matt.

Industrial Cafe · « **Reply #2 on:** February 13, 2009, 05:20:18 PM »

yeah, one side is longer than the other.
gots ta be narrowed- it doesn't fit by about a half inch.
take a gander at this here link>

http://forums.sohc4.net/index.php?topic=34880.0
just scroll down to the pics

Industrial Cafe · « **Reply #3 on:** February 14, 2009, 07:49:33 AM »

moved!?
Its' a single cam cb750 with an attempted dohc swing arm!!
its not "other bike" subject matter.
did you not you see the part about the K1?
oh well, maybe someone in the "other bikes" section can help. maybe someone with extensive experience in Yamaha RD350s.
I guess I should be thanking this "SteveD" character.

thank you Steve, thank you for moving my post.

754 · « **Reply #4 on:** February 14, 2009, 08:38:06 AM »

I agree this should be a comon mod for the 750. I think more/all does come off the one side though.

After reading all on this earlier posted, i am thinking that Bronze bushings are far easier to live with and get made.

I dont think that the needles come out easily and could be reused, plus they are pricey. and must run on a hardened spacer.

If I had one in hand I could probably tell you a home method for removal.. will try to get over to 1080s to look at a 800 one he has.
754

bryanj · « **Reply #5 on:** February 14, 2009, 10:31:31 AM »

From Memory its a special puller that slides through then a pilot expands the far end that has a lip and you use a slide hammer to extract the bearing----This ALWAYS wrecks the bearing as the inner end is rounded whilst the outer is flat.

Industrial Cafe · « **Reply #6 on:** February 14, 2009, 11:05:11 AM »

I figured I would need a slide puller.
I'm not worried about effin' up the bearing... there's some bearings on ebay for $19.99.
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=250365129276&fromMakeTrack=true

I also noticed the inner race(tube the bolt goes into) has a little over a half inch of space to move the bearing (on the cut side) in.

But I'm not yet sure if I can press the bearing a half inch further into the pivot tube without machining it inside...
methinks the end cap should fit fine after the cut.
$:-\$

754 · « **Reply #7 on:** February 14, 2009, 07:45:21 PM »

Cut a disc, just under the size of the bearing out of 1/8 or thicker metal.

slit down the centre, then nick the corners off...install in back of bearing.. wiggle in place.

Insert rod near bearing ID size.. and wail away...

MRieck · « **Reply #8 on:** February 15, 2009, 07:04:46 AM »

Quote from: bryanj on February 14, 2009, 10:31:31 AM

From Memory its a special puller that slides through then a pilot expands the far end that has a lip and you use a slide hammer to extract the bearing----This ALWAYS wrecks the bearing as the inner end is rounded whilst the outer is flat.

Exactly. I just removed the needle bearings in a JMC swingarm with the blind puller attachement on the slide hammer. Keep in mind the bearing housings have a "thick" end (the code is posted on it)....that's the side you push against when installing them

Industrial Cafe · « **Reply #9 on:** February 15, 2009, 03:57:15 PM »

uh... i Got it out

I felt like such a dumb hillbilly pounding away with a hammer 'n' chisel.

oops...

all better $:-\$

well after all that, it looks like I did ok.
Although I had to grind off the chisel burrs on the swingarm, it's only .001 out of round.
now I just need to press the new bearing in, when it gets here.

Industrial Cafe · « **Reply #10 on:** February 15, 2009, 03:59:38 PM »

MRieck's idea would have been great, if I read it yesterday

754 · « **Reply #11 on:** February 15, 2009, 09:01:01 PM »

Shoulda tried Mikes method or mine.. & saved scarring up the swingarm...

Industrial Cafe · « **Reply #12 on:** February 15, 2009, 09:35:30 PM »

Oh yeah, don't I know it.

Industrial Cafe · « **Reply #13 on:** February 18, 2009, 03:58:21 PM »

I had to drill out the holes at the pivot point on the frame to 41/64 inch to accommodate the 16mm bolt. I pressed in the new bearings and did a mockup.

I gotta turn down some axle shims, cause using the late model shims doesn't work. it makes the tire a half inch off center.
maybe a late model cush drive takes up the 3/8 inch needed on the chain side... I dunno, I don't have one yet.

Industrial Cafe · « **Reply #14 on:** February 18, 2009, 04:12:15 PM »

I must admit I didn't expect the shocks to be so far back, but I'll fix that with an additional shock mount welded in later.

Industrial Cafe · « **Reply #15 on:** February 24, 2009, 08:18:04 AM »

I should have cut a 1/4 inch off each end of the inner race.
but it works.

Industrial Cafe · « **Reply #16 on:** March 30, 2009, 09:43:18 PM »

K8 carrier because I got a k8 motor. wouldn't have needed it if I had the original K1 motor.
had to put an extra 1/4 inch spacer on the other side with the oem DOHC brake side spacer.