|
|
Post by Doo640ER on Feb 7, 2021 17:18:21 GMT
|
|
|
|
Post by 775 on Feb 7, 2021 17:31:56 GMT
Great photos! Thanks for sharing. Let us know what the issue was.
|
|
|
|
Post by olyman on Feb 7, 2021 18:20:27 GMT
Right on! Great photos! That looked like it was a riot, even though the ego took a hit. My wild guess is the chain broke and jammed it up tight, but could be wrong. AND you still got a trophy! My 70 left me stranded 3km from home today too  so I know the feeling! Sounds like a wrenching day for both of us. |
|
|
|
Post by ericr on Feb 7, 2021 20:21:39 GMT
That's only 1.863 miles  |
|
|
|
Post by olyman on Feb 7, 2021 22:41:18 GMT
That's only 1.863 miles uphill both ways .... in the snow ... |
|
olympic
Full Member
Fresh gas first pull got be a DOOO
Posts: 201
|
Post by olympic on Feb 8, 2021 4:19:43 GMT
Cool photos there Doo640ER my 69 did the same thing years ago seized the upper bearing in the chaincase and bent the secondary clutch shaft also.
|
|
|
|
Post by joeolympique on Feb 8, 2021 21:34:41 GMT
My wild guess is the chain broke and jammed it up tight, I wouldn't be surprised if the chain is, indeed, the culprit. From personal experience... When restoring the '71 292 a few years back I discovered a link with a hair line fracture. I felt very fortunate to see it. The chain was just sitting there on the bench minding its own business. I wasn't actually inspecting it but somehow it was looking up at me. It was just a little glint in the light and it caught my attention so I put my zoomies on for a closer look. Sure enough that link was bad. I went into my stash of spare chains and found three of the correct length. Two of those had the same problem. So out of a total of four chains three had the same affliction...that's a pattern not a coincidence. I had no idea to look for that in the first place or that this might be a common failure. It got me thinking that maybe original chains should be replaced as a matter of rule. |
|
|
|
Post by Doo640ER on Feb 14, 2021 0:06:10 GMT
Hi gang! Happy Saturday evening! Thanks for all of your thoughts on and comments on my little ordeal. Also glad you liked the pictures. So this morning I went out in the garage and dug into the Oly. Damn, I had to drill-out those rivets! Now I have experienced the exact reason why most people use screws or update the chassis and cowl to have the 70-style clasps to hold the hood down. When I took the upper large plug off the chaincase I was happy to see that the chain was still in tact, and my first guess was correct. The inner top bearing of the chaincase was trashed. When I finally got the shaft out, all of the rollers fell out onto the top of the tunnel, LOL. Well, somewhat of an easy fix. Cleaned it all up and changed the bearing and race and there you have it. Now the question is why did this happen? My thoughts are 1. Cheap bearings? I used KML bearings, made in the USA. 2. Clutches not properly aligned? I know the sled was surging ahead a little at idle. 3. Oil not getting to that bearing? I used 80w90 full synthetic Amzoil gear oil. I had this left over from my 4-wheeler differentials. Maybe its too thick? Might switch to tranny fluid? On another note, how tight is the nut supposed to be tightened on the upper chaincase sprocket. I know I did not overtighten it when I put the sled back together. Maybe I had it too loose? Maybe there was some grit inside the chaincase from when I beadblasted it? The oil looks a little spent right now, so I will change it out regardless. Well here are a couple of pictures.   |
|
|
|
Post by olyman on Feb 14, 2021 0:41:52 GMT
Hey thats not too bad at all to deal with! I think you had the right oil (80/90)... not sure what synthetic does? I can see the bearing heating up based on being held too tight, but sounds like you didnt do that. When I tighten up that top nut I go slow when its starting to snug up. Use one hand to turn the clutch back and forth to feel for friction, and once it starts to show friction tension, back off just enough to get the cotter pin in. That "should" be enough to not heat up and it should turn easily by hand. The spring washer should hold enough tension to keep it happy.
Maybe you had a bad bearing or maybe it got something in it that made it unhappy. But I think it should work fine with new bearing and oil after a good cleaning.
|
|
|
|
Post by powerwagon75 on Feb 14, 2021 7:21:00 GMT
...On another note, how tight is the nut supposed to be tightened on the upper chaincase sprocket. I know I did not overtighten it when I put the sled back together. Maybe I had it too loose?...
Not for sure with yours being a ‘67, but a few years newer manual shows both eccentric adjust and non-eccentric call for the top sprocket nut to be tightened down completely, then backed off 1/6 turn (one hex flat). I put 80/90 Yamalube synthetic in mine, and I can assure you that oil gets around in there plenty well. I would think if the bearings were too loose, you would have gotten other symptoms first, like a rattle or vibration from the driven shaft at certain times. Just some thoughts that came to mind. |
|
|
|
Post by ericr on Feb 14, 2021 13:35:22 GMT
Ahhh powerwagon may be on to something- it's tapered like a wheel bearing, snug to seat then backed off a hex- perhaps not enough bearing clearance?
I will be making my hood a lift off and swapping to a '68 style helix secondary for better back shifting.
|
|
|
|
Post by 1970tnt on Feb 14, 2021 20:25:40 GMT
BEARNG DEFINATELY GOT HOT, I WOULD SAY NO OIL OR BAD BEARING UNLESS YOU REALY TIGHEN THE HE!! OUT OF IT. LIKE OTHERS HAVE SAID TIGHEN AND BACK OFF A BIT. IS THERE ANYWAY YOU MIGHT HAVE PT IT BACK TOGETHER WRONG???
|
|
so I know the feeling! Sounds like a wrenching day for both of us.
