Possibility of Crank Shifting???

[Coyote]

Thinking of a gear drive for my 2001 softail but I'm hearing that they can result in problems if the crank shifts. A couple of questions.

What would cause the crank to shift?

How common a problem is this or is it pretty rare?

What is the result of this with a gear drive?

Thanks for any help

'yote

[Blackpearlultra]

I'm not an expert but I will give it a shot. Due to bearing and or bushing wear your crank can shit in or out slightly. If you change to gear drive with a shifting crank , or having run out, it could cause the gear alignment to slip away from each other since the drive gear goes directly to your cam gears. If these gears slipped past each other or even walked away slightly it would cause timing issues and possible major engine damage to your ride. To determine if you have run out you need to open up the cam case and put a dial indicator to check it. Typically I think most guys change their crank bearings when they do them. The other thing to think about is if your bike has a press fit crank and you are going to build lots of HP you may want to look into a welded crank.
I have included a file that S&S have on line showing a gear drive set up install.
Keep us posted on how you make out.

[speed]

I'm not aware of such a problem being wide spread.

However, all cranks have some run out. When installing gear drive cams it's important to shim them properly. If they are shimmed too lose you will hear a lot of clatter. If you shim them too tight you will hear a constant whine. Any competent mechanic will do it properly.

Cheers,

Speed

[ritz]

What a coincidence.

After experiencing progressively rough idle issues with my 00' Fat Boy (50K+ miles), I had the problem diagnosed (by 3 shops) as due to shifting of the crankshaft.

I uncovered the following article which detailed the problem as one of the achilles heals of the Twin Cam and the remedy:
http://www.hotbikeweb.com/tech/0809_hbkp_building_a_stout_twin_cam_crank/index.html

The engine has been removed from the bike and shipped to Charlie Lawlor of 'Small Block Charlies' (http://www.motorcyclemachine.com/) to remediate the problem.

[speed]

Welcome to the Hawg Zone ritz.

Cheers,

Speed