New style rear main oil seal

[jackonz]

Below is a message I posted some time ago and had zero response, so I have put it in a new query and it's below, as I have finished the latest task that my wife wanted done completed I now want to get back to my bike.

Well after waiting an age I have finally received the new OEM rear main seal, having looked at it it matches what is in BMW service information 00 053 88 (2324) and confirms that what was supplied originally to me was a discontinued type.

So I have questions in that it states in the above bulletin "If the shaft is rounded or chamfered sufficiently, the seal can be pushed on. If the shaft is NOT rounded or chamfered, you must pre-shape the seal prior to installation. the desired shape can usually be obtained by pushing the seal on to the drift to install it".
Now my question is as I have purchased an install tool from BMW Motorworks that had what appears to be a step that I assume match the seal face on the flywheel, if I am correct then I can use that to pre-form the seal, question is how long should I leave it in there to form it, am thinking I will push the seal in then leave the tool in there for whatever I need to then install the flywheel. Or should I put a small chamfer to the leading edge of the flywheel seal area before installing it.

[gspd]

...

[RPGR90s]

Many years ago I installed the latest seal on my '74 R90s. I remember heating the seal in warm engine oil and then installing it on the flywheel flange to sit over night. Then install as normal.

[jackonz]

Many years ago I installed the latest seal on my '74 R90s. I remember heating the seal in warm engine oil and then installing it on the flywheel flange to sit over night. Then install as normal.

Well according to the Service info relating to this seal it is to be installed dry?

[Rob Frankham]

This seems to be a very slow thread... a couple of observations.

1) The original seals were installed wet, the newer seals are installed dry. Newer seals shopuold be 'preformed' prior to installation. Some come already on a plastic former which means they are already pre-formed. sliding the seal onto a (very clean) drift will achieve the same effect. The seal should be slid straight from the drift or formerand should not be removed from one then placed on the other. The time spent on the shaping 'arbor' isn't relevant.

2) The lip on the new seal needs to bend inwards towards the back of the seal when it is installed. As received it is straight.

3) It can be theoretically installed if the end of the crankshaft is chamfered or rounded. Personally I would avoid this approach as I find it difficult to see how you can ensure that the lip bends inwards. I certainly wouldn't chamfer or round the end of the shaft as any roughness left by the gtinding process would damage the seal.

BMW service bulletin 00 053 88 refers

Don't know if that helps

Rob

My apologies for the typos... typed in a hurry

R

[jackonz]

This seems to be a very slow thread... a couple of observations.

1) The original seals were installed wet, the newer seals are installed dry. Newer seals shopuold be 'preformed' prior to installation. Some come already on a plastic former which means they are already pre-formed. sliding the seal onto a (very clean) drift will achieve the same effect. The seal should be slid straight from the drift or formerand should not be removed from one then placed on the other. The time spent on the shaping 'arbor' isn't relevant.

2) The lip on the new seal needs to bend inwards towards the back of the seal when it is installed. As received it is straight.

3) It can be theoretically installed if the end of the crankshaft is chamfered or rounded. Personally I would avoid this approach as I find it difficult to see how you can ensure that the lip bends inwards. I certainly wouldn't chamfer or round the end of the shaft as any roughness left by the gtinding process would damage the seal.

BMW service bulletin 00 053 88 refers

Don't know if that helps

Rob

Hi Rob,

I knew you would have some insight in to this thank you, the tool I have purchased for installation of the seal has what looks like a match for the seal face on the flywheel so that would pre-form the seal, I purchased it fro BMW Motorworks and it has a threaded bolt hole in the centre to facilitate removal of the tool once the seal is installed.

Cant recall where I read it but some people were saying that you should polish the seal face on the flywheel before fitting it? wondered if you knew anything about this.