bearing lock tabs

Discuss mechanical problems here.
Forum rules
By using this site, you agree to our rules. Please see: Terms of Use
Post Reply
martin418
Minor Fan
Posts: 327
Joined: Tue Jun 24, 2014 9:54 pm
MMOC Member: No

bearing lock tabs

Post by martin418 »

i have a 1098 engine which does not have lock tabs on the big end or main bearings but it has spring washers instead , is this normal for latter units or should all A series engines have lock tabs , i have got the engine out sorting a leaking rear block to back plate gasket and i am doing all the bottom end gaskets at the same time , i have bought a lock tab set but i wondered if it's worth disturbing the bearings as it all seems ok and has been like this for 5000 miles +
MarkyB
Minor Maniac
Posts: 7845
Joined: Thu Jan 25, 2007 3:18 pm
Location: South East London
MMOC Member: No

Re: bearing lock tabs

Post by MarkyB »

I'd fit the lock tabs, the bearings wont mind any disturbance, unlike gaskets.

"Once you break something you will see how it was put together"
bmcecosse
Minor Maniac
Posts: 46561
Joined: Wed Feb 16, 2005 11:24 pm
Location: ML9
MMOC Member: No

Re: bearing lock tabs

Post by bmcecosse »

I've never heard of a leaking rear block gasket - are you sure that's the problem? Washers were never specified - but there is an argument that locktabs are not good either - the soft metal of the tab can allow the stress on the fixing bolt to relax... Later Mini engines had no tabs - or washers. And I don't think the factory used Loctite either - although many engine builders use that as a matter of course.
ImageImage
Image
martin418
Minor Fan
Posts: 327
Joined: Tue Jun 24, 2014 9:54 pm
MMOC Member: No

Re: bearing lock tabs

Post by martin418 »

the gasket is leaking mainly because who ever fitted the back plate left out three bolts !! [ 2 by the oil pump] , there is a clear mark on the gasket where oil was leaking ,
bmcecosse
Minor Maniac
Posts: 46561
Joined: Wed Feb 16, 2005 11:24 pm
Location: ML9
MMOC Member: No

Re: bearing lock tabs

Post by bmcecosse »

Ahhh that would explain it....
ImageImage
Image
les
Minor Maniac
Posts: 9181
Joined: Tue Feb 12, 2002 12:00 am
Location: kent
MMOC Member: Yes

Re: bearing lock tabs

Post by les »

Interestingly I've also wondered about the softness of locktabs and the possibility of allowing the bolts or nuts to relax but have considered the initial compressing of the tabs is enough to compact the material to it's limit. From experience I can't recall anything I've had to undo involving tabs, to be loose. However I daresay modern locking liquids are a suitable replacement, if preferred.

martin418
Minor Fan
Posts: 327
Joined: Tue Jun 24, 2014 9:54 pm
MMOC Member: No

Re: bearing lock tabs

Post by martin418 »

i fitted the tabs and i the metal they are made from is a thick as a washer and took a fair bit of bending , they torqued down nicely ,
Post Reply