Rebuilding WD shift tower

Hi All, after lurking for a while i finally joined the group..mainly because I have a problem, snow plowing with my WD, she got stuck in reverse, tried all the tricks to line up everything after taking shift lever out,no go. I removed the tower and it seems like the reverse lever & fork move way too loose, no tension at all like the other two. I'm thinking theres a spring missing ?. I have several diagrams that show a spring I've searched websites for hours and  cannot find any place to buy these , Even tried E bay for a whole tower. Any ideas folks ?

No spring resistance on my original WD for R......been like that far back as can remember.Dont know if R has a detent spring but would think so? Too lazy to look in parts books.

Thanks for the replies!, I took another look at it, (you know how it's better to walk away for a while sometimes ) and I can defineatly see that a spring and ball are missing from reverse ,the lever/fork really flop around. I will give Sandy Lake a call with the part numbers suggested (Super help there !) And yes she's a 1950 regular WD with a straight shifter. BTW said shifter shows some wear at the base so will weld it build it back up to specs while it's apart..

Boy am I happy I took the suggestion to call Sandy Lake in Pa. Sarah in parts had what I needed in stock. Bill the service manager took the time to help me with repair tips and directed me to a link on there webpage to print out directions to put it all back together
Thanks to all !.. I really like this forum already   
I'll post back when parts arrive and let you know how it goes

Good morning all,
 I was able to get my WD up and running, was indeed the detent ball and spring that popped out, I don't know why reverse shaft over traveled , causing that to happen, but I put a sleeve on the reverse shaft so as not to happen again. Bill at Sandy lake suggested 1/2" EMT conduit which in my case was too small. I used a piece of brass pipe roughly 5/8 ID cut 2 1/4" long, slid over nicely.I had to loosen the set screws for the fork and collar and use a punch to get both end caps off so shaft would move far enough over to slide it on . 18g wire was perfect for rewiring through set screws.I can say  it went together pretty well, I had to move around the gears in the case a bit to have them line up with the forks,which I had set in 2nd gear. Biggest problem was getting the spring and ball set ,and after about and hour and a half of that nonsense, I took it to my local tranny shop ,5 minutes and no charge !,( so I'll send him some cookies) Building up the end of the shifter with weld helped a lot, shifts nice and tight now.1st pic is brass sleeve 2nd shaft over travel ,if you look at the upper right you'll see hole where sping& ball popped out)uploads/20472/leverovertravel.jpg