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RD400 crank install question

Started by JBeasty, August 24, 2022, 07:03:27 PM

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JBeasty

I put new outer main bearings on my RD crank, and it rocks just a little bit resting in the bottom case. It's the bearing on the left side (gen side) that doesn't use the 1/2 circlip. I can press down on the outer shaft and make it drop down a bit. If I put the top case on and press down on it, it nearly goes away. I'm thinking (hoping) it will go away entirely when I install the new seals and torque down all the top and bottom case bolts/nuts. Still, it has me concerned. I pressed that left bearing on as far as it could go. There is a slight gap between the bearing and the side of the housing (you can see it in the second pic) - Can you press them on too far?
1977 RD400

m in sc

no you can't. its fine. do a test bolt together of the case w no sealant,  check for free spinning, I'm sure its fine

JBeasty

1977 RD400

rodneya

Do those bearings have the little locating pins? are the centre ones in their pockets?

1976RD400C

After setting the crank in the lower case I take a wooden hammer handle and tap the bearings and center seal down so it settles in nice.
'76 RD400 green  '76 RD400 red   '84 RZ350

m in sc

Quote from: rodneya on August 25, 2022, 10:50:07 AM
Do those bearings have the little locating pins? are the center ones in their pockets?
^ this, but i assumed you knew that. good point though.

JBeasty

Quote from: rodneya on August 25, 2022, 10:50:07 AM
Do those bearings have the little locating pins? are the centre ones in their pockets?

The new outer bearings don't have the locating pins, and the center ones are in their pockets. But don't assume I know anything  :huh:
1977 RD400

JBeasty

Quote from: 1976RD400C on August 25, 2022, 05:51:50 PM
After setting the crank in the lower case I take a wooden hammer handle and tap the bearings and center seal down so it settles in nice.

I will give that a try, thanks  :like:
1977 RD400

rodneya

Quote from: JBeasty on August 27, 2022, 03:39:19 PM
Quote from: rodneya on August 25, 2022, 10:50:07 AM
Do those bearings have the little locating pins? are the centre ones in their pockets?

The new outer bearings don't have the locating pins, and the center ones are in their pockets. But don't assume I know anything  :huh:

What are you using on the flywheel side to stop the bearing spinning in the case if it does not have a locating pin?

JBeasty

So I've read 2 schools of thought on this. One is that if the bearing freezes and it has the locating pin, it'll just tear up your case. And the other is the bearing can potentially spin around in the housing (if it doesn't have the pin) causing damage that way. In any case, apparently people have done it both ways without issue? I went ahead and got some cheaper NACHI bearings with no pins. Hopefully I won't regret it   :undecided:
1977 RD400

m in sc

chuck q used to talk about this. just use a tiny drop of loctite on the bearing saddle in the bottom case. itll be fine.

rodneya

Koyo max Load 8 ball banshee crank bearings are only about $30 each and come with an o ring. Quality bearing and no worries about a locating pin or locktite

JBeasty

Thanks guys. Probably should have asked. I'm trying not to ask about every little thing. I'll do the loctite trick.
1977 RD400

Striker1423

Loctite green, retaining compound 680. Just a tiny drop as Mark said. I saw a picture of someones with it gobbed on... don't do that lol.

JBeasty

#14
Quote from: rodneya on August 29, 2022, 05:53:04 PM
Koyo max Load 8 ball banshee crank bearings are only about $30 each and come with an o ring. Quality bearing and no worries about a locating pin or locktite

I ended up pulling my cases apart again and I'm gonna send the crank to John Ritter. Are these the right bearings, and can they be used to replace all 4 (inner and outer)?
https://www.amazon.com/Yamaha-Banshee-Crankshaft-Bearing-6305NRC3/dp/B07PYKD3BG
1977 RD400