Split Lock Washers On Main Bearing Caps Of Flathead Motor
 

Hi Guys-
I'm starting to reassemble my late flathead motor after machining. This motor had never been apart since new. When I took it apart, there were split lock washers on the center and rear main cap bolts. I can't think of any modern engine that uses split lock washers there. Any opinions on whether they are necessary or not?
Thanks guys.

Re: Split Lock Washers On Main Bearing Caps Of Flathead Motor
 

Split lock washers don't seem like a good idea for this application.
Imagine what would happen if a lock washer breaks and bolt starts to loosen.

Re: Split Lock Washers On Main Bearing Caps Of Flathead Motor
 

I’ve seen that in the 8BA engines. Lock washers under the center and rear but none in the front .

Re: Split Lock Washers On Main Bearing Caps Of Flathead Motor
 

Don't do it! DD

Re: Split Lock Washers On Main Bearing Caps Of Flathead Motor
 

Split lock washers are ineffective at functioning as "lock" washers. In fact, they can lead to premature loosening of the joint. They shouldn't be used anywhere critical.

Re: Split Lock Washers On Main Bearing Caps Of Flathead Motor
 

Do you mean spring washer? If so as above don’t do it.

Re: Split Lock Washers On Main Bearing Caps Of Flathead Motor
 

That's the way they came from the factory. The 2 bolts with washers are slightly longer than the front one.

Re: Split Lock Washers On Main Bearing Caps Of Flathead Motor
 

Back in my checkered past, when I was managing a fleet of 90 pieces of heavy equipment, I always insisted that the technicians (fancy term for mechanic) would not use lock washers when installing the bolts for u-joints on drivelines. I saw lots of these washers fail when the bolts are being torqued. The operative work is torque, as that is what tensions a bolt or stud so it does not loosen. Just my opinion.

Re: Split Lock Washers On Main Bearing Caps Of Flathead Motor
 

Canadian C69A engines use the same setup; spring washers under centre and rear main cap bolts. Question is; why did Ford do that? Earlier engines used studs with tie wire to prevent nuts/studs backing out.

Re: Split Lock Washers On Main Bearing Caps Of Flathead Motor
 

The French motors use sheet metal tab devices on the mains. Maybe they decided the spring lock washers were not a good idea.

Mart.

Re: Split Lock Washers On Main Bearing Caps Of Flathead Motor
 

I was always taught to use a grade #8 flat washer, din;t always do it but on a race motor do. Not sure where this comes from but torqing to 1oo bl it doesn't make sense to use a lock washer.

Re: Split Lock Washers On Main Bearing Caps Of Flathead Motor
 

I know of a very recent case where a disc brake kit that came with a flat washer to be installed under the spring washer for the disc calipers bolts, it had not been on the road for more than a month. Epic fail as the flat washer allowed the spring washer to rotate and the hold down bolt fell out ,luckily at parking lot speed. Just use the spring washer in this case so it has the parent metal to bite into. Wire those suckers on for added security.
Apologies if this is a slight Hijack.