HarleyTechTalk

1999 Road king classic (TC88).

I was feeling optimistic as I went to install the cam plate today. Looking forward to starting the bike soon. Patience and time finally starting to pay off.

Sooo. Got everything aligned and snugged up the six bolts retaining the plate (in the fsm order). Started torqueing and #1 screw starts spinning without catching. Next thing I have the plate back off looking down the lower ring dowel at half the threads missing. No way I stripped this. Just not enough material came out to account for that many threads and I only snugged it up to that point. I'm doubtful that the mechanic who took it apart stripped it, he wasn't tightening anything down. I'm guessing that the bike has been running this way since only God and the hack who stripped it to begin with know.

I'm seeing only a couple of options here. Running a tap through it is pointless. Too much missing material. I could:

1) Use a longer screw. The cam cover screws are 1/4" longer and also GR8. I checked and maybe I can add a washer if it doesn't bottom out. This would grab a good piece of intact thread. Hopefully that wouldn't interfere with the cam cover. I consider this at this point only because there's really only about three good months left in the riding season and I plan to split the cases this winter anyway to have the flywheels balanced and welded. If it holds up until then I can fix the problem properly. This would be a hack to get through the interim.

2) Helicoil? If it weren't in the ring dowel I'd be less concerned. Don't really know if there's enough material in the dowel to drill and tap for a helicoil but it's an option to look at.

Any options I'm missing? Thoughts? Suggestions?

Thanks for reading.

Try the Longer bolts.   

I drilled deeper through the upper dowel ring and tapped the hole deeper. I don't remember right now why but I had to grind the shank of the tap to a smaller diameter to get this done.

QuoteI drilled deeper through the upper dowel ring and tapped the hole deeper.

Do you remember how much deeper you went (just for reference)?

I just went and looked at the tap and started remembering what I did. I drilled with the cam plate in place. I used every inch of the modified tap that I could, 2 1/8" from the cam plate to the bottom of the hole. The shank of the tap was bigger than the root diameter of the tap is the reason for grinding the shank.

Remember, this was the upper dowel ring hole, lower may have less meat in the bottom of the hole.

If you want to give it a shot I'll send you the proper drill and the tap and you need not return it. PM me if interested.

Thanks truck, Appreciate the generous offer. I'm going to have another look at this and see what I can do. I won't put you to the trouble unless it's absolutely necessary.

Since your in temporary hack mode...maybe if there is 3 or more threads in the bottom of the hole use a stud and 12pt. nut instead of a screw.  Common practice to use a stud/nut at the 2 dowel locations.  Several here order the stud/nut from Summit,  stud: Dorman #675-086,  nut: ARP #300-8330.  Hopefully the stud will reach far enough to get any good threads.  Low torque and Loctite.   Rick

No trouble at all, I hope you get it sorted out.

Care taken when studding... Don't bottom out TIGHT. That can pull existing threads out. Lock-tight (your choice red or blue I prefer Blue) Cure over night or use a heat gun to dry sooner...

Just my way

signed....BUBBIE

#1 and #2 bolt tightening sequence of the cam plate.  Those two bolts go through dowels, so there is only limited thread for those two behind the dowel.  Many have stripped those threads.  Therefore, I always use double threaded studs in those two holes ONLY.  The regular bolts in the other 4 holes of the cam plate.  The other 4 holes have a full compliment of threads and never a problem.  The automotive studs I use are 1/4"x20; 1/4"x28; 1 1/2" long studs.  One inch is too short.  I use the ARP 12-point black oxide nuts on them.  The studs I get at True Value hardware and the nuts at Summit Racing.  I always keep a stash of these in my garage.

After chasing and cleaning the bolt holes (quick dry electrical spray) I use red loctite on the (1/4"x20) threads that go into the casing, for those two studs.  I use blue loctite on the nuts (1/4"x28).  When installing the studs, I only "snug firm" by double nutting with the ARP nuts...don't over tighten.  They are studs and also bound by the red loctite so just firm snug.  It is helpful to get a 12-point 5/16" ignition wrench for the inner nut (for the thin space) when doing the double nutting.  Any wrench on the outer nut (like a 12-point 8mm wrench) works.

Using the studs, there is zero chance of stripping threads no matter now many times a person goes into the cam chest.  The little ARP nuts fit perfect into the cam plate.

Now that you've passed up the opportunity to install studs the first time, there is a good kit for putting in a coil in there prior to installing the studs.  (Do not drill deeper.)  The kit is the Perma-Coil 1208-104 (1/4-20).  I install the coils with red Loctite.

There is no need to wait until the red cures.  You can install the plate and bolts/nuts right away.  Just make sure the leave it a day or two for everything to cure before starting the engine.  Good luck and next time use the studs the first time, and every time...give the next guy a break.

I drew this to scale a long time ago to show the thread engagement difference between a normal hole and a dowled hole.

Stud them the first opportunity and never look back.

I like the stud idea a lot. Good advice.

Quote from: les on July 06, 2014, 05:13:07 PM

The little ARP nuts fit perfect into the cam plate.

I got the studs and nuts ready to go with my upgrade.
I used a Delkron cam plate and the nuts are a neat fit into the cam plate but not enough room to get a socket on them.
I might look at drilling oversize to get a socket on them next time but I went with bolts 1/4" longer for those two.

I've never used the Delkron plate, but yes I've heard there is not enough room for the nuts with that particular plate.

Incidentally, when using the Perma-Coil Kit, you leave the [old] dowels in place to guide the drill.  Then remove the dowels, tap, install the coil, and install a new set of dowels.  Again, if installing the studs the first time you don't need to R&R the dowels or use a coil...you eliminate the hassle all together.

Quote from: les on July 06, 2014, 05:13:07 PM
#1 and #2 bolt tightening sequence of the cam plate.  Those two bolts go through dowels, so there is only limited thread for those two behind the dowel.  Many have stripped those threads.  Therefore, I always use double threaded studs in those two holes ONLY.  The regular bolts in the other 4 holes of the cam plate.  The other 4 holes have a full compliment of threads and never a problem.  The automotive studs I use are 1/4"x20; 1/4"x28; 1 1/2" long studs.  One inch is too short.  I use the ARP 12-point black oxide nuts on them.  The studs I get at True Value hardware and the nuts at Summit Racing.  I always keep a stash of these in my garage.

After chasing and cleaning the bolt holes (quick dry electrical spray) I use red loctite on the (1/4"x20) threads that go into the casing, for those two studs.  I use blue loctite on the nuts (1/4"x28).  When installing the studs, I only "snug firm" by double nutting with the ARP nuts...don't over tighten.  They are studs and also bound by the red loctite so just firm snug.  It is helpful to get a 12-point 5/16" ignition wrench for the inner nut (for the thin space) when doing the double nutting.  Any wrench on the outer nut (like a 12-point 8mm wrench) works.

Using the studs, there is zero chance of stripping threads no matter now many times a person goes into the cam chest.  The little ARP nuts fit perfect into the cam plate.

Now that you've passed up the opportunity to install studs the first time, there is a good kit for putting in a coil in there prior to installing the studs.  (Do not drill deeper.)  The kit is the Perma-Coil 1208-104 (1/4-20).  I install the coils with red Loctite.

There is no need to wait until the red cures.  You can install the plate and bolts/nuts right away.  Just make sure the leave it a day or two for everything to cure before starting the engine.  Good luck and next time use the studs the first time, and every time...give the next guy a break.

            Good stuff Les..................... 

Any special tools involved in pulling the dowels?

If I can't find perma-coil, is helicoil compatable?

I pull the dowels using a pair of vice locks.  I use them sideways and using the teeth.  I'm careful with not scratching the surface of the casing.  Be patient and careful working them out.

I meant vice grips.  Any appropriate coil will work.  I just like the Perma-coil kit.

Thanks Les, you have been a big help. I really appreciate the input that you and the other posters have given on this.

put a bolt into the dowel before you put vise grips on it so that it doesnt fully collapse

Good idea. Thanks.

Quote from: FSG on July 08, 2014, 04:36:53 AM
put a bolt into the dowel before you put vise grips on it so that it doesnt fully collapse

Thanks for the tip!

QuoteAny special tools involved in pulling the dowels?

Run a 5/16th tap in the ring dowel a few threads, just enough to get a good bite on it, then wiggle and pull it out.

IIRC, someone on here repaired one of these stripped holes with a heli-coil and didn't remove the dowel, just went right through it.

this apply to 07 up motor as well? just had same thing happen on a 120 case alwasy torqued it to spec 3 time changing cams im get my torque wrench recalibrated to see if thats the reason,i like stud idea dose work on SE plate?

Quote from: WideWildGlide on July 09, 2014, 08:42:46 AM
this apply to 07 up motor as well? just had same thing happen on a 120 case alwasy torqued it to spec 3 time changing cams im get my torque wrench recalibrated to see if thats the reason,i like stud idea dose work on SE plate?

Forget about getting the torque wrench recalibrated.  That's not the problem.  The problem is that the first time you take the cam plate off you should install the studs...which eliminates the thread stripping problem.