R80/7 Rear Main Seal

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jackonz
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Joined: Sat Oct 30, 2021 5:29 pm

R80/7 Rear Main Seal

Post by jackonz »

Hi, I have finally recieved my new rear main seal from BMW Motorworks in the UK I know how to install it but according to the Clymer/Haynes manual it says to soak the seal in oil prior to instalation, now looking at others on YouTube who have installed them including the guy at Boxer2valve install them dry.
Old seal is a white one and the new seal is black and has a platic insert in it to hold the seal shape while in transit.

So the wuestion is install dry or not?

Phil J.

NZ
Last edited by Steve in Golden on Fri Jan 28, 2022 4:38 pm, edited 1 time in total.
Reason: Corrected typo in post title
Phil J

Nelson NZ.
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gspd
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Re: R8/7 Rear Main Seal

Post by gspd »

DRY
Mechanic from Hell
"I remember every raging second of it...
My bike was on fire, the road was on fire, and I was on fire.
It was the best ride ever!"
Rob Frankham
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Location: Scotland UK, 20 miles from civilisation up a dead end road!
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Re: R8/7 Rear Main Seal

Post by Rob Frankham »

This is the BMW service bulletin relating to the new type seal...
Crank seal.jpg
Crank seal.jpg (186.39 KiB) Viewed 1816 times
Rob
ImageImageImage
jackonz
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Joined: Sat Oct 30, 2021 5:29 pm

Re: R8/7 Rear Main Seal

Post by jackonz »

Than you your information is most helpful, with two long weekends back to back I have and four days leave I have 10 days to tinker as I please on the bike.

Happy times.
Phil J

Nelson NZ.
jackonz
Posts: 206
Joined: Sat Oct 30, 2021 5:29 pm

Re: R80/7 Rear Main Seal

Post by jackonz »

Well what a surprize that was replacing the seal, I thought I was going to have to battle getting the old seal out so I used a seak hook from work and a piece of flat steel to lever it off, so ready to pull hard and it came out so easily I was shocked to me it was nowhere near as tight as it should have been in the case, the old seal and O ring were the white cerity and as I understand these were the original item.

New seals in and gearbox back in.

Slow and steady rules the day.
Phil J

Nelson NZ.
jackonz
Posts: 206
Joined: Sat Oct 30, 2021 5:29 pm

Re: R8/7 Rear Main Seal

Post by jackonz »

Rob Frankham wrote: Fri Jan 28, 2022 9:51 am This is the BMW service bulletin relating to the new type seal...

Crank seal.jpg

Rob
Hi Rob, with reference to the BMW service bulletin you sent me some time ago am unsure of the correct part number I should use, on the Real OEM parts list the latest number is 11111338342, BMW Motor Works list this as a Modified scraper Type, they also list part number 11111261739 Original spring type and on the OEM parts list was replace by 338342 in February 2002.

Am I correct I should use 338342 ? as for installation some people seem to use a flat plate type (Brooks Airhead and Boxer 2 Valve) and other use a tool with a shoulder that I assume is made to form the seal during installation.

Hopefully you can guide me in the correct direction as I don't want to pull it apart a third time.

Am adding this after looking at Max BMW and the parts list they show only 11111261739 and it states that the seal needs to be pre formed prior to fitting the flywheel, they also have the service bulletin attached you sent me linked to it, they do not show the latest part number as per Real OEM parts list.

Then on Boxer 2 Valve only lists the new seal 11111338342 as an equivalent seal and is pre-formed, the tool they list to install it is a flat plate.

All very confusing.

Many Thanks.
Phil J

Nelson NZ.
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