Rear main seal -186

[FC229]

HI folks,
I am in the process of tidying up the 186. The main reason I've stripped it is to do the rear main seal, which I never got quite right the first time around. I helped a friend do his grey a few years ago with no problems, but don't remember the tricks. I think I can get it but would be interested in getting some tips on how to get it right. Don't want to do all this work and still have that annoying leak. Did a bit of a  search but found no step by step advice. Any help would be greatly appreciated.

Thanks

David

[jasonr70002]

I soak mine in oil overnight then push into the groove and then work it in with a smooth round piece of steel like a socket or extension bar until all the way in then trim slightly above the flat surface to allow for crush when the crank is in and torqued down,  probably about 1mm would be enough because if you trim exactly level it will leak from new as the crush will open a hole. Hope this helps mate.
Cheers Jason

[FC229]

Hi Jason,
thanks for your reply. I recall having to leave the top slightly proud last time I did it, and I shaped the sides so where it sat high didn't end up squash out and stop the bearing cap closing fully. I read a few tips yesterday from various web sites which added things like gluing the bottom of the seal in place, and gluing the bearing cap to eliminate oil leaks through the cap. Also something about needing a dummy shaft to get it right. I thought there would be info in the workshop manual, but there's nothing. I was thinking I might do 1 half first, tighten the cap down on the crank, trim it, then the other half, but not too sure.
I might try to get my hands on the red motor workshop manual from the library.

[simins]

I am aware there are two types of rear main seals for a 186 a graphite impregnated seal or a neopreme seal not sure if inter changeable . But the neopreme seal i used has given no dramas after using a blue silicone perma seal type of product. gluing the seal into the bearing cap and gluing both little flappy ends hope this helps
           good luck Simon Addison

[FB_MAD]

I've also used the neoprene rear oil seal in my 149 and have done around 5000 miles so far with no evidence of a leak whatsoever.I was hesitant to fit it as I've always used the rope type rear seals but it has been better so far than the old rope seals I've used in the past which by 5000 miles show some oil wetness in the general area ( not an actual leak as such ).

I glued mine ( neoprene seal ) in place with a special silicon sealant that is used on jap engine sumps with a dob of the silicon sealant  also on the end tabs before fitting rear main cap.

With rope seals I soak the rope seals in oil overnight then fit as is by pushing the seal in firmly by using my thumb.I use the graphite impregnated seals and oil soak them overnight as well.Don't use any glue as glue won't stick to an oily part anyway.I nip off the excess seal with a razor blade leaving approx 1 mm each side and on both seal halves  for crush.The crank is slightly tighter because I don't crush fit the seal with the special GMH tool that you are supposed to use.The oil soaked seal is prelubed lube on startup and it burnishes into the right seal fitment  with  its sealing effect quickly within first few minutes of engine running.

Thats how I do the rope seals and no problems to date doing them that way.