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Engine rear mian seal..."new" style vs "old" style

Posted: Thu Apr 28, 2011 9:47 pm
by moosehead
The bike 1978 R100/7 -- "under the plywood behind the drive shed" find

Been sorting out ths bike last few weeks. Surprisingly in pretty good shape both mechnically and cosmetically...considering

Checking clutch etc and loads of engine oil in case pointed me to rear main seal and/or oil pump O ring. So off with the flywheel and ..bingo...both were shot.

Had order into Motobins for few other parts so was adding new main seal and O ring etc to order. However they list a "new, improved, BMW recommended " replacement seal (teflon?) as well as the old style with garter spring.

Question...guess I'll go with "new improved" one. Is installation of these newer type seals pretty straight forward as older ones? Any special "tricks" Think I read they should go in dry?

I can't find my old main seal installer tool I last used about 10 years ago...think after 2 house moves in last 5 years it found itself in the trash somewhere as I can't find the bugger anywhere. It was a beauty my old neighbour made for me. O well, have to dig through the hockey puck bag as I think they would work with a little alteration....maybe :roll:

Re: Engine rear mian seal..."new" style vs "old" style

Posted: Thu Apr 28, 2011 10:10 pm
by dougie
http://www.motobins.co.uk/motobins-hints-and-tips.php
Look for "rear crankshaft seals"
I used the "new" style, soaked it in oil for 1 hour, it doesn't leak so far.

Re: Engine rear mian seal..."new" style vs "old" style

Posted: Thu Apr 28, 2011 10:40 pm
by moosehead
Yea, Motobins is where I;m ordering the new style seal from.

Soaked in oil for hour? Thought I read somewhere they go in dry but I could be mistaken, Seem to me to oil it up first makes sense to me.

Did you use a seal installer?? I lost, mispalced an old one a friend made for me so was wondering how you put these new ones in? With new ones I was thinking to just tap it in to correct depth but an automotive gearhead friend said the new teflon ones are hard to put in without a proper seal installing tool.

PS: Dougie where are you located? Ontario or out west? Just wonderin', maybe meet up for a ride sometime...if we actually get any kind of decent weather here on Canukstan...ha ha...

Bob

Re: Engine rear mian seal..."new" style vs "old" style

Posted: Thu Apr 28, 2011 10:43 pm
by moosehead
Stupid me, I see your located in Burlington in your listing! I pop down to Belfountain to meet a few friends the odd time. If yo go up there let me know...lotsa airheads there last time I was there!

Re: Engine rear mian seal..."new" style vs "old" style

Posted: Fri Apr 29, 2011 4:39 am
by dougie
Yes I used a homemade seal installer. I will dig out the picture and specs and post it later today.

Re: Engine rear mian seal..."new" style vs "old" style

Posted: Fri Apr 29, 2011 7:12 am
by moosehead
That would be great...thanks!

Back to THE WEDDING

Re: Engine rear mian seal..."new" style vs "old" style

Posted: Fri Apr 29, 2011 9:22 am
by SteveD
moosehead wrote:That would be great...thanks!

Back to THE WEDDING
15 yo old oilhead bike escorts! Nice touch.

Re: Engine rear mian seal..."new" style vs "old" style

Posted: Fri Apr 29, 2011 10:27 am
by dougie
moosehead wrote:That would be great...thanks!
Well I tried to get this drawing into the computer without any success. Unfortunately I have very limited patience with computers when they don't do what I want.
Someone on here originally sent it to me so hopefully they will show up with the drawing.

Re: Engine rear mian seal..."new" style vs "old" style

Posted: Fri Apr 29, 2011 3:24 pm
by mattcfish
dougie wrote:http://www.motobins.co.uk/motobins-hints-and-tips.php
Look for "rear crankshaft seals"
I used the "new" style, soaked it in oil for 1 hour, it doesn't leak so far.
The instructions used to say to soak them in hot oil. If I recall, when the first Teflon seals came out they were very stiff and even seemed brittle, so soaking made since. The newer ones are much more pliable. I've been putting them on dry with no issues.

Re: Engine rear mian seal..."new" style vs "old" style

Posted: Fri Apr 29, 2011 3:32 pm
by Garnet
I installed the new style dry about 6000 miles back in one of my /5 engines and the old style on my other about 2000 miles back. Neither leak so I can't tell which is better. :?