If you like our site, please consider joining our club!
By joining you will help ensure that we can continue to provide this service
JOIN HERE!

Difficulties while crank assembly

Post Reply
User avatar
Darryl.Richman
Posts: 2141
Joined: Fri Oct 27, 2006 3:00 am
Has thanked: 1 time
Been thanked: 9 times

Difficulties while crank assembly

Post by Darryl.Richman »

Although the shop manuals say to heat the case to 100C/212F, that's not hot enough. Most people find something in the 150-175C/300-350F range to make it a lot easier. At this temperature, the crank and its bearing will just drop right into place. And the case will stay hot enough, long enough, to allow you get everything in place without rushing and worrying about it.

The quick and dirty way to tell when it's hot enough is when "spit sizzles". I bought an infrared thermometer instead, and it has been useful for other things, too.
--Darryl Richman

Allan.Atherton
Posts: 503
Joined: Fri Oct 27, 2006 3:00 am

Re: Difficulties while crank assembly

Post by Allan.Atherton »

... heated rear bearing house/cover with a torch too a much higher temperature then the 100 Celsius advised by the workshop manual... the bearing with the crank end in it stuck in about a 1/3rd of its way. What was I doing wrong? What now? ...
Guenther Wuest does his crank R/R with a grille with the top closed onto the top of the case for 10 minutes or so, which evenly heats the whole case.
http://home.insightbb.com/~aatherton/R6 ... USaut6.jpg
I don't think a torch can heat the case properly. The flame overheats a small part of the case, and then the heat is rapidly dissipated into the rest of the cold case. Most people use their kitchen oven to heat the case. Put it in your oven to get things moving again.

User avatar
TrophyMoto
Posts: 78
Joined: Sun Mar 29, 2009 9:41 am

Difficulties while crank assembly

Post by TrophyMoto »

I put a crank in this sunday ..I used a hot plate on low w/ a 14x12x1/2" alu plate on the burner. I also covered the block with a blanket ,it took about 4hrs to reach 200deg ,but when it did the block was throughly heat soaked. the cranked dropped in with little fuss , I had already pre heated the front carrier ,popped it on and pulled the crank into place.... viola!!

I 2nd the use of an infrared thermometer ,I use this tool WAY more than I ever thought I would.

User avatar
VBMWMO
Posts: 1322
Joined: Sun Aug 23, 2009 7:49 pm

Difficulties while crank assembly

Post by VBMWMO »

I inserted the crank fitted with bearings and slingers into the crankcase, heated rear bearing house/cover with a torch too a much higher temperature then the 100 Celsius advised by the workshop manual, fully turned a 10.9 strong 8 mm bolt into front crank thread and banged on it with a plastic hammer, with no results: the bearing with the crank end in it stuck in about a 1/3rd of its way. What was I doing wrong? What now? Any advice will be much appreciated.
Thank you.
Dedicated to the Preservation of Classic and Antique BMW Motorcycles.

Post Reply