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Drive side crankcase - help with identifying broken part

Submitted by david_henshaw on Sat, 17/04/2010
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Commando

Hi,

I am in the process of dismantling my commando crankcases and have noticed a broken part on the drive side between the oil seal and the main bearing. I need help with identifying it and finding a replacement. I've tried the usual place (Parts Manual, Haynes and Google searches etc) but cannot find any information. My fear is it's a non-replaceable item....

I've attached a photo. Any advice is greatly appreciated.

Kind regards

Stuart

Attachments missingPart.jpg

Submitted by keith_glassborow on Mon, 19/04/2010

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Is it broken or has someone removed/bored the diameter and does the seal still locate OK? Do you have a pic of the outside? It seems you might only have a couple of mm of face for the seal to seat on. I'd say you have to see if a good aluminum welder can build up the inner diameter and then get it bored and faced both sides. It doesn't look irrepairable but it is quite thin there as you know.

Submitted by david_henshaw on Mon, 19/04/2010

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Hi Keith,

Thanks for responding.

It looks broken rather than bored. The original makes it look like a part that fits in between the oil seal on the outside and then the bearing inside but I can't be sure.

Submitted by keith_glassborow on Mon, 19/04/2010

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Stuart,

Unfortunately it's all one piece, machined externally for the chaincase spigot and seal recess with a slight raised step on the inside where the bearing seats, to provide clearance. The machined area is very thin there as you can see and they often have radial cracks from the bore. The thing is, will the seal seat OK on the outside? You might be OK.

Submitted by david_henshaw on Tue, 20/04/2010

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The seal sits on the outside but there is nothing between it and the bearing. I must admit it doesn't look like a fixed piece, it looks more like a shim that can be removed and replaced. But I don't know. I think I need to get a welder to have a look. I was just hoping it was a named part that I could replace.

Thanks again for your help Keith.

Submitted by keith_glassborow on Tue, 20/04/2010

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Definitely all one piece Stuart and it seems like someone has been overenthusiastic with a screwdriver getting the seal out sometime and they've bust the casting.I'd say that provided the seal has some metal to seat against axially it will be OK, not nice but OK. The fact that the seal in the garter/lip area has no metal between it and the bearing is not a big issue. Even without any material to press against the seal can be installed so it's flush with the outside. BTW, many car engine crank and diff seals need to be pressed to a dimension with no material acting as a stop. Good luck, hope you get it fixed. Doesn't sound beyond a good ally welder but it will need to be superclean for welding, no oil etc.

Submitted by david_henshaw on Tue, 20/04/2010

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Thanks Keith. Lots of helpful advice there. I'm going to get the case cleaned up and then take to a reputable welder to see if they can do anything.

Thanks again, Stuart.

 


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