Driveshaft adapter coming loose

[rickmiller48]

What is the trick to keeping that nut tight that holds the driveshaft adapter on the countershaft.  I was doing real tight with red lock tight, but that has failed me 3 times now.  Once with the old engine and old driveshaft, once with the new engine and old driveshaft, and now with the new engine and new driveshaft.  I must be missing something here, but I can't put my finger on what.

Thanks,
Rick

[apm motorsports]

you should have two allen screws tapped into the adpt that hold the nut from spinning out

[rickmiller48]

I guess they are the set screws this talks about -

67. SPROCKET ADAPTERS: The sprocket adapters must remain stock, within the stock dimensions, steel thickness, location and configurations of the original, as currently delivered by U.S. Legend Cars International
Set screws for the sprocket adapter nut are permitted. Lightening the sprocket adapter for weight savings in any way is illegal.

I don't have them and don't have any holes for them.  Can someone tell me the size, length, etc of these.  It sounds like a good idea and can't be too hard to drill a couple holes and tap them.  Also, do these set screws have locking nuts on them or are they just little bolts?

[apm motorsports]

you do not want nuts on them  1 and 3 oclock 1/4 20 set screw 3/4 long I will  post how far back from end of coupling tomorrow or measure where for nut ends up from front of .

[rickmiller48]

If you can measure how far from the end they go that sounds perfect.  Also, is there a torque spec on the big nut and or on the set screws?  Also, do you red lock tight the nut and both set screws?

Thanks,
Rick

[thunder938]

I use red lock tight and set screws and have never had it come loose..

[rickmiller48]

Don't mean to be dumb, but do the set screws ever try to back out?  Also, you said 1 and 3 o'clock.  That is pretty close together.  I would have thought they would be spread out more for balance.  Not saying it is wrong, just not what I would have expected.  Wrong would be mine with no holes or set screws that keeps coming loose.  Also, how much allen screw sticks out when they are tight? 

Thanks again, sorry for being a pest,
Rick

[thunder938]

Mine are across from each other and do NOT stick out once tight.  If they stick out they will / could  break  with the allen tool.  I had a buddy's break.  The new ones sink down in to the adapter to support the thin walls at the end.  I tighten the nut with lock tight annd make sure that the set screw hit the flat of the nut. 

[rickmiller48]

So the heads of the allen bolts are actually countersunk into the body of the adapter?  Or are you saying the bolt just bottoms onto the adapter with the head of the allen bolt completely above the surface?

Now I am being a pest (or dense).

Thanks,
Rick

[rickmiller48]

Ok.  Now I am home and pulled it all apart and still have stupid questions.  The engine side cover that the clutch slave cylinder mounts to is less than 3/16" from the adapter at the point that it looks like the set screw would need to go, so I would think I would have to counter sink.  Adapter is only 1/4" thick so if I go counter sinking, I won't have alot of meat left for threads.  Even if I only partially counter sink (say 1/8") then that only leaves another 1/8" of threads for me to strip out as soon as I get a little ham fisted on the ratchet.  Now if I chopped that bracket I could get another 1/8" or so but would my slave cylinder be ok being held basically by 2 of the 3 bolts?  Another option I guess would be to try to find some fairly long, 1/2" or longer I would guess, set screws that have no head like you find as set screws on some collars and sheaves.

Thanks again for all the help,
Rick

[thunder938]

"So the heads of the allen bolts are actually countersunk into the body of the adapter" Thats it and like I stated make sure the set screws hit the flat of the nut.  I had them fall on the corners once and I had to give the nut a bit more to turn it so the flats lines up

[Tornadorex]

There is no (head) on the screws they are set screws. the allen wrench fits into the body of the set screw so it can go below the top of the hole.

[Vern Houseman]

Rick did you get it ? or do you need some more help ? let me know ? Vern

[rickmiller48]

I did it last night.  Looks like it should work.  I did bugger up the one hole as my tap broke.  So I had to punch that one out bigger and helicoil it.  Thanks to everyone for their help.  As always, thanks Vern, see you at Lincoln.

Rick

[JGRacing]

If you ever have to back out a broken tap, I used this tool on my motor that worked great at getting it out without more damage.  Cannot remember the name of the product, but if you search on my post on this site it is out there.