What engine is in the 9400 combineIJ JDparts shows a 6359. Is that the engine that is actually in it. If so, it shows a 6359 crank new from JD for $1,830.oo. I might be able to help you out if i know what engine you have for sure.
That's a known problem with those engines caused by a loss of torque on the cap screw that holds the damper on the front of the engine. It's either that or the other known problem, which is an incorrectly made damper. Either way, the result is the same, and you need a new crankshaft. There is a complete kit available to replace the crankshaft, bearings, and damper. Get with your Deere dealer for the rest of the info. It's easy to find on DTAC.
I can get you a brand new 6359 crank for $1000 plus shipping which will depend on your location....I can also get you the kit and bearings to rebuild your engine. If you are interested just send me an email.
The crankshaft_damper_bearing kit is available from Deere for $1830.00 under part number RE502190, or part number RE502191 for $1990.00. If you go through a Deere dealer and use OEM Deere parts, you might be able to get some relief on the parts and_or labor, as it's a known problem. I think we've had a couple of 9400s here do the same thing, but I'm not sure what if anything they did as far as warranty or picking up part of the tab. If you stick with Deere parts you'll know you have the correct parts to solve the problem. Who knows with will-fit parts if you're considering that option. I recently had a 4630 engine that had been overhauled with will-fit parts back apart and was not impressed with the quality of the kit.
I would say it would be in the ball park of about $1990.00 for the crankshaft its self. You will also have to take into consideration the bolts and labor too. Good luck Brent
G-man,, if you look at JDParts.com the part number RE502190 is just the crank alone....no aother kits with it....$1830 for crank alone through JD parts