Jump to content

Exploding Main Bearing


Recommended Posts

Purchased an '87 a few months ago in awesome shape for 700 bucks. Great deal right? Unfortunately, on the first test ride after fixing oil leeks, replacing missing bolts and what not, my new toy locked up. After a dreadful tear down this is what I found after splitting the case. Obviously I need a crank. Anybody know if these cases are repairable, or if it will even hurt to just slap a new crank and bearings in? Notice the surface where the bearing rides on the clutch side.

http://i1288.photobucket.com/albums/b497/xrac3rx85/DSCN1139_zpse8fec000.jpg

http://i1288.photobucket.com/albums/b497/xrac3rx85/DSCN1141_zps5fee3be8.jpg

Also check out this last pic. Anybody have an explanation for why anybody would do something like this? If not I am sure you will get a laugh out of it.

http://i1288.photobucket.com/albums/b497/xrac3rx85/DSCN1143_zpsedcb37dd.jpg

Link to comment
Share on other sites

lol^^ true. Sure they getto rigged the hell out of it, But i did get a complete machine for 700. So what do you think the purpose of those sweet pepsi shims are? That crank was rebuilt at some point. Has a fairly new looking wiseco rod on the right side and a stocker on the left lol, I'm still trying to Wrap my head around why you would replace one rod and not the other. I meen its not like there made of gold.

Anyway back to the case. Is that usable? Can i just smooth that surface out and put a new crank in? or will it hurt the new bearings?

Link to comment
Share on other sites

I was figuring on new cases. Just didn't want to replace if i didn't have to. The cases are immaculate other than that damage the bearing caused. It kinda dug a trench in the surface. Now, I am a welder by profession, and i am sure that could be welded and machined back if it would have to be. But the cost! I am sure would far surpass the cost of buying used cases.

Link to comment
Share on other sites

New cases can be had for $100-200 all day. Prob not worth the time. If those are 87 cases your prob better off with newer anyway. Mine only have I think half a grove for holding some of the bearings in. I forget which ones though if its crank trans or what. I remember seeing newer ones when I had my turd apart and mine was missing a slot or two. Think maybe it was crank bearing. Slept since then though.

Link to comment
Share on other sites

I was figuring on new cases. Just didn't want to replace if i didn't have to. The cases are immaculate other than that damage the bearing caused. It kinda dug a trench in the surface. Now, I am a welder by profession, and i am sure that could be welded and machined back if it would have to be. But the cost! I am sure would far surpass the cost of buying used cases.

Check the cost of a new line bore and just replace with larger diameter bearings.

Link to comment
Share on other sites

Check the cost of a new line bore and just replace with larger diameter bearings.

This is just a slightly better jury rigg!!!!!! Then you would have to take apart ANY crank you buy to put bigger bearings on it and it will bee next to impossible to find seals to fit that will hold up. The pepsi can shims were put in there to take up the clearance from where the bearing bores were already to big. Buy a matched set of cases and a good crank and build it.

Link to comment
Share on other sites

This is just a slightly better jury rigg!!!!!! Then you would have to take apart ANY crank you buy to put bigger bearings on it and it will bee next to impossible to find seals to fit that will hold up. The pepsi can shims were put in there to take up the clearance from where the bearing bores were already to big. Buy a matched set of cases and a good crank and build it.

Agree 100% but at least it's an option for him.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...