I have a 1979 FLH with a 1984 evolution engine i fitted to the frame i have a problem with the pinion shaft key after about 150 miles the pinion gear shears the T KEY and it throws the timing off ! this has happen twice since i built the engine , first thing i noticed is the the pinion shaft nut was completly loose and on the 2nd time i so called fixed it, it happened it was very loose !!now i want to add the the crank assembly is the 90-92 assembly that uses the smaller skinner pinion shaft and T key, i noticed the the t key goes into the worm drive the spacer and the pinion shaft gear ,but it doesnt seam to go into the pinion shaft gear very much at all?? so here is the question im asking
(1) What is causing the nut to loosen up i used lock tight on the threads but i didnt have the right socket to torque the nut but i did do it up super tight ?? i have now ordered the correct socket !

(2) because the t key doesnt seam to go into the pinion gear very much i was thinking of machining the spacer so that the key will enter the pinion gear more , but doing this will also move the pinion shaft gear inwards but this still will allow plenty of gear surface to mesh

any ideas??

 

No ideas?

 

Well, i don't know for sure about the problem you are facing specifically, but I do know that without the right socket, it's damn-near impossible to get the nut tightened up to the proper torque spec. That is probably the main root cause of your problem. Shafts with keys are super-sensitive to the torque and usually need really high torque to stay put. Clean it all up, use a fresh key, fresh keyway, clean threads and red locktite, get the proper socket and torque the nut to spec. I'll bet it stays put.

 

What's concerning me the most is how much of the key it left for the pinion gear to lock in I'm sure your correct about the tool I've ordered it and it's on it's way I'll take a pic and post it here to show what I'm talking about

 

Here a pic showing the pinion shaft and the worm gear and spacer you can see that there is only a little piece of the key for the pinion gear to grab

 

Another pic

 

I think there may be some mixed up parts in there...early motors use 2 keys and a two piece pinion gear (gear + spacer) later ones use one key and a one piece pinion gear....not sure if it is possible to mix them up but that is how it looks to me from here.

I haven't had an early bottom end apart lately and so can't really be sure but it does look that way.

 

Wouldn't be possible to mix the 3 different generation up , the first has the larger tapered shaft like on the shovel that ends in 89 that uses the 2 semi circle keys ,the second generation has the smaller pinion non tapered shaft that uses a single t key this what i have mine bike has the early cases but the later assembly , the third is similar to the 2nd but the pinion shaft is 1/4 longer and has a corse thread the reason its long it to acommadate the pinion shaft which i think is longer thats also the reason the 93- on nose cones are different !

 

Sweet, Looking at the pics again I thought that might be the case but your shaft looks like its single key and has the 2 piece pinion though.......

 

Your correct I have the 90-92 pinion shaft assembly with the 93 on pinion gear and worm gear I don't know how I ordered the wrong gears I have to see my receipts