Having split the cases, it appears that the bearing at the drive sprocket has been spinning. That can't be good. Shiny aluminum showing in the pocket and a ridge I can feel to the rear.
Should I use a little Loctite of some sort?
Remembering having to use it on the H1 triple crank bearings long ago [Why do I remember that from 36 yrs ago? Because I used a little too much, locked down the crank and had to take it apart again]:
Yes, red loctite is what I have used on crank bearings missing pins in the past as well. Have not had issues.
Obv should look into why your bearing was spinning. Hopefully you are already going to replace it.
I believe there may also be more specific products out there. Hopefully someone else chimes in.
What Loctite number did you use motodreams?
That bearing rolls smooth as butter and the circlip half is there on the bottom case half like it should be. I guess it could have happened before some previous owner got into it. They must have replaced the crank seals at least once since 1977. Those are still quite pliable.
I see your crank seal replacement thread. Will add a pic to it.
I use Loctite 620 green retaining compound, high temp for slip fit cylindrical applications.
There may be another version of the formula that works better, but I haven't had any issues.
I used it on my crank bearing journals.
I wanna say Chuck Quenzler tipped me in on it when I noticed some fretting in my cases.
I don't see why you couldn't use it in the trans, it should work well.
(https://uploads.tapatalk-cdn.com/20190421/d56e1625a9ae9181c714207646f1de42.jpg)
(https://uploads.tapatalk-cdn.com/20190421/6e29104dd9248107df24b974f13de7da.jpg)
Quote from: motodreams on April 20, 2019, 06:05:07 PM
Yes, red loctite is what I have used on crank bearings missing pins in the past as well. Have not had issues.
Obv should look into why your bearing was spinning. Hopefully you are already going to replace it.
I believe there may also be more specific products out there. Hopefully someone else chimes in.
No! Don't Use RED!!
Use 620 or 640 green retaining loctite.
The only difference from the 620 to 640 is the 620 is for high temp.
I use 640 as the more expensive 620 not needed for RD engines.
Chuck
I found the drive bearing had spun on my 77 400 had 28,000 miles don't know if I was the first to split cases or not, replaced bearing like $28.00 and used loctite sleeve retainer 640 it says " high strength" the 620 says for high high temp and large gaps
Heave - we use the Loctite retaining stuff (green) at work with decent results. Do not use the red stuff that is made for bolts. My RZ cases had a similar problem to yours and I put it together with the green Loctite. Long term durability yet to be determined as I only have about 15 miles on the rebuild. I didn't sweat it too much as there aren't many good alternatives to bearings moving in cases, so we'll see. Sorry can't give the definitive answer yet.
I'm gonna proceed with getting some 640 and some Yamabond or equal.
Thanks for the help guys!
Will chalk it up to many abrupt 1st gear roll-ons at 5500 rpm to make the front wheel come up.
Since Chuck did his thing to make the cylinders pump air better :thumbs:, it might not take as much coaxing now, so I'd better lock that bearing in.
Loctite 620 is some badass stuff. Like the others said it's the proper stuff to use on cylindrical bearing journals etc.
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Do you guys recommend the locktite for general purposes on a stock rebuild with all new bearings in an r5?
Doesn't hurt to, but not as critical on 350 cases that have steel line bores in them.
When the 400's cases were made, Yamaha did away with the steel line bores and with the +8mm bigger stroke crank we see more wear in the line bore so it's really needed from them IMO.
Another advice...retaRD is going to regret using WAY TOO MUCH, he's never going to split those cases again...
3 drops max each case half for each bearing. 6 drops total for each bearing and do the lab seal as well.
I even cream it thin with my finger to the point you don't see much of it on there, that is perfect amount.
Chuck
Quote from: SUPERTUNE on April 20, 2019, 10:05:49 PM
Quote from: motodreams on April 20, 2019, 06:05:07 PM
Yes, red loctite is what I have used on crank bearings missing pins in the past as well. Have not had issues.
Obv should look into why your bearing was spinning. Hopefully you are already going to replace it.
I believe there may also be more specific products out there. Hopefully someone else chimes in.
No! Don't Use RED!!
Use 620 or 640 green retaining loctite.
The only difference from the 620 to 640 is the 620 is for high temp.
I use 640 as the more expensive 620 not needed for RD engines.
Chuck
Red works. You are in need of a small amount of friction over a large surface area that already have substantial amounts of pressure on it.
Is green better? Probably. Is it more applicable here? Definitely. Is red wrong like you have stated? No.
The loctite product descriptions would indicate red is applicable here as well.
Will it work? Sometimes. In more worn cases with a gap.
But it can dry too fast and lock up the crank bearings and that is a no no.
So why take a chance and have to re-do it all over? MY OPINION ONLY.
Quote from: SUPERTUNE on April 23, 2019, 08:26:43 AM
Another advice...retaRD is going to regret using WAY TOO MUCH, he's never going to split those cases again...
3 drops max each case half for each bearing. 6 drops total for each bearing and do the lab seal as well.
I even cream it thin with my finger to the point you don't see much of it on there, that is perfect amount.
Chuck
Hey Chuck it's not piled on, the picture makes it look like it is. A dab will do ya.
Yeah, I didn't do the lab seal...
I used red on my H1 crank long ago. It did lock up.
Disassembled and reapplied less and it was okay after that. It can set up quite thick after you close the case.
I used green in a mechanical assembly job many years ago to fix precision bearings onto shafts for a commutator block. This stuff will not set up properly unless it is under pressure. Any over-application outside a tight-fit joint will stay liquid for hours or days. The amount required to cement is almost invisible. You can't have enough to squeeze out of the joint or it will end up in the bearing. Nearly impossible to get it out of a small bearing once it's in.
It doesn't fill gaps very well either and when it does it isn't as strong as it is under a press-fit.
Looking at this application I would say that it probably would be good enough on one side of the case only and applied with a swab to the center of the case journal. You don't need a proud bead as long as there is a good match between surfaces. Oil free everywhere and I might buff the outside of the bearing with scotch brite to break any glaze.
If the application is done correctly you need a torch to get it apart without damaging things. Especially on threaded joints. Probably have to put the case into an oven at about 500 degrees if you cemented the whole bearing.
IR8D8R
^ correct. ive used it a few times, the stuff is ridiculous but behaves exactly as described.
Sometimes, its hard to keep stuff from spinning. :taz:
(http://www.2strokeworld.net/wp-content/uploads/MISC-BS/spinning.gif)
:haw:
There are different formulas, one is press fit, one is slip fit.
Quote from: IR8D8R on April 24, 2019, 10:14:41 AM
I used green in a mechanical assembly job many years ago to fix precision bearings onto shafts for a commutator block. This stuff will not set up properly unless it is under pressure. Any over-application outside a tight-fit joint will stay liquid for hours or days. The amount required to cement is almost invisible. You can't have enough to squeeze out of the joint or it will end up in the bearing. Nearly impossible to get it out of a small bearing once it's in.
It doesn't fill gaps very well either and when it does it isn't as strong as it is under a press-fit.
Looking at this application I would say that it probably would be good enough on one side of the case only and applied with a swab to the center of the case journal. You don't need a proud bead as long as there is a good match between surfaces. Oil free everywhere and I might buff the outside of the bearing with scotch brite to break any glaze.
If the application is done correctly you need a torch to get it apart without damaging things. Especially on threaded joints. Probably have to put the case into an oven at about 500 degrees if you cemented the whole bearing.
IR8D8R
When dealing with pressed bearings on shafts for pressed fit repair that have spun and worn really bad to the point there's gaps and slop in the bearing race or housing and not even close, Use Loctite Quickmetal 660 press fit repair.
I have used it for at least 20 years with really good results.
There is a few Youtube videos too.
Chuck