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problem with crank main bearing locktabs

Posted: Fri Sep 01, 2006 8:29 pm
by nleader
Dear all,

I am rebuilding a 1098 and have got stuck on the locktabs for the crank main bearing caps. As you can see from the pics on the site (link below), when I try and tighten down the bolt, they are crumpling, and rings are being gouged out by the bolt head, creating tiny bits of swarf, not good as I understand in the sump


http://www.communityfora.plus.com/mm.html

I have tried two different suppliers (though the tabs seem very similar, maybe same manufacturer?) and two differet torque wrenches (though same make).

Any ideas gratefully recieved. I'm sure I'm making an elementary mistake somewhere.

Nick Leader

Posted: Fri Sep 01, 2006 8:54 pm
by bmcecosse
No - that's normal i'm afraid!! Sure you are using the correct torque setting ? Just use a magnet to collect the unwanted bits.

Posted: Sat Sep 02, 2006 7:48 am
by Innovator
I leave them out and use hardend washers instead.

I do not believe in lock tabs and never use them for the following reasons

1) For them to bend they have to be soft, having a soft washer under a fastner head is a bad idea as it will creep over time so reducing the clamping force. This is worse with a on and off load.

2) A properly torqued fastner should not require any other locking.

3) Lock tabs, lock wire etc will only stop the fastner dropping off / out and not help retain the clamping load.

John

Posted: Sat Sep 02, 2006 9:08 am
by nleader
ah. my mistake was to think there was a mistake, hardened washers sound a good idea.

Posted: Sat Sep 02, 2006 5:24 pm
by bmcecosse
Mini engines have no tabs. If you are worried - clean the threads and use a spot of Loctite.

Posted: Sat Sep 02, 2006 9:54 pm
by les
Have you tried a smear of oil under the bolt heads? Or you could use loctite threadlock

Posted: Sun Sep 03, 2006 10:25 pm
by nleader
thank you to all, I think hardened washers and maybe locktite sounds the way to go.

Nick Leader

Posted: Mon Sep 04, 2006 9:26 pm
by les
test

Posted: Mon Sep 04, 2006 9:30 pm
by Kevin
test
And what sort did you have Les :wink:

Posted: Mon Sep 04, 2006 9:53 pm
by les
A test to test if I could post the word test, and when I saw the word test in the post I knew my test tested positive!