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LD innocenti: o-ring seal on the retaining plate

PostPosted: Fri Dec 12, 2014 1:37 pm
by sillywalker
Hello,
I have to restore an engine from a 1956 LD 150 innocenti.
I know french LD better than italian (I'm a french frog!), and you know better italian ones
There are a few things different

One of these things that don't appear on french ones is the retaining plate of the crank seal on the gearbox side
As you know, there is normally a specific - "u" shaped- oil seal on a circular lip located on the gearbox side of the plate
This seal must be renewed by an o-ring (47x2mm) supplied by casalambretta

My problem is that I don't really know how to put that ring. On the outer border of the lip, the o-ring seems too tight (it doesn't stay on place after fitting), is that the correct place, have I to stick it with loctite?
Or is that a wrong place? Or have I to stick it with loctite on the lip of the plate? or is the inner border of the lip the the o-ring the right place? (then the size of the o-ring is really wrong)

Tanks for your help and advices

Alex'

Re: LD innocenti: o-ring seal on the retaining plate

PostPosted: Sun Dec 14, 2014 9:23 pm
by sillywalker
Well, anybody seems to have any idea about that

Maybe I look at that problem in a wrong way
I thought I have to fit the O-ring on the retaining plate before fitting the plate in the crankcase (like it was maybe done in 1956 with the 'u-shaped' seal).

But it looks easier to put the o-ring first in the crankcase and then, after that, to fit the retaining plate
Am I right?

In that case, is that better to stick the o-ring seal with loctite or not? the o-ring seal is 2mm thick, it seems big, I wish it won't change the perfect location of the crank after fitting.

If you have some experience of that, thank you for informations or your advices

Re: LD innocenti: o-ring seal on the retaining plate

PostPosted: Mon Dec 15, 2014 8:55 pm
by Rob Miller
Assemble the plate,the bearing, any shims and the bevel gear onto the crankshaft and tighten the (left hand threaded) nut. Then slide the o ring over the bearing, up to the plate. Then assemble the crank into the casing. I usually loctite the bevel nut as well as using the lockwasher.
I hope this helps.
Rob.

Re: LD innocenti: o-ring seal on the retaining plate

PostPosted: Mon Dec 15, 2014 9:27 pm
by Steve J
Rob Miller wrote:Assemble the plate,the bearing, any shims and the bevel gear onto the crankshaft and tighten the (left hand threaded) nut. Then slide the o ring over the bearing, up to the plate. Then assemble the crank into the casing. I usually loctite the bevel nut as well as using the lockwasher.
I hope this helps.
Rob.


Yes, that's exactly what I do with the later Mk2 & Mk3 LD engines - there is no need to use Loctite or any other sealant on the 'O' ring. As long as the rubber ring is new and is the correct size, there will be no problems with sealing. I have used non-hardening sealants (Red Hermetite or similar) in the past, but it's not something I would now use.

Re: LD innocenti: o-ring seal on the retaining plate

PostPosted: Tue Dec 16, 2014 12:36 pm
by sillywalker
Thank you!! Then I know I won't do any mistake with it.
The O-ring should be the correct size (if casalambretta is not wrong). It is 2mm thick.
I really appreciate your help
Have a good day
Alex'