case bolt stripped
#1
case bolt stripped
Hi
I need a bit of help here. All last season I had a oil seep from the upper right side case bolt , primary side, the one to the right of the timing hole on top.The bottom end was rebuilt by a qualified harley mechanic ( ya ya I know ) and I put a good 6000 miles on the motor last season without a problem other than the bolt seepage.
It was suggested I pull the bolt and smear some silicone in the hole and reinstall the bolt torqued to spec which is about 17 lbs. So I went ahead today and pulled the bolt and to my surprise it was snug tight only. I smeared the bolt and hole with blue Hylomar and when I attempted to torque with my inch pound torque wrench I got the dreaded feeling that it wasn't torquing.
I tightened it back up snug and here I sit.
So question what are your thoughts on this situation?
Kind of the way I see it is it is at least at the top of the case and the cylinder studs are taking alot of the stress. I really really don't want to strip this motor down splitting the cases for this bolt. Perhaps some positive feedback would take this knott out of my stomach.
If the picture uploaded it is the bolt circled in red.
I need a bit of help here. All last season I had a oil seep from the upper right side case bolt , primary side, the one to the right of the timing hole on top.The bottom end was rebuilt by a qualified harley mechanic ( ya ya I know ) and I put a good 6000 miles on the motor last season without a problem other than the bolt seepage.
It was suggested I pull the bolt and smear some silicone in the hole and reinstall the bolt torqued to spec which is about 17 lbs. So I went ahead today and pulled the bolt and to my surprise it was snug tight only. I smeared the bolt and hole with blue Hylomar and when I attempted to torque with my inch pound torque wrench I got the dreaded feeling that it wasn't torquing.
I tightened it back up snug and here I sit.
So question what are your thoughts on this situation?
Kind of the way I see it is it is at least at the top of the case and the cylinder studs are taking alot of the stress. I really really don't want to strip this motor down splitting the cases for this bolt. Perhaps some positive feedback would take this knott out of my stomach.
If the picture uploaded it is the bolt circled in red.
#3
After giving a great deal of thought to the situation I decided to pull the bolt back out, strangely enough there is quite a bit of motor oil on the bolt. So I got the vernier calipers out to measure the hole depth compared to the bolt depth and just as I thought the shaft and threads of the bolt is actually about 3.50 inches the hole depth is about 3.75 inches so I think I now have a couple options, I can try red lock tighting in a a stud about 4.25 inches and put a washer and nut or try a longer bolt. I may get lucky enough that when company that manufactured the cases drilled and tapped the holes they tapped right to the bottom.
I was also thinking to go get a helicoil kit for the bolt thread size and get a 4.5 inch long drill bit if they exist to drill the hole for helicoil, but I'm thinking stud might be a better direction to try first.
Any thoughts?
I was also thinking to go get a helicoil kit for the bolt thread size and get a 4.5 inch long drill bit if they exist to drill the hole for helicoil, but I'm thinking stud might be a better direction to try first.
Any thoughts?
#4
You may be able to get a slightly longer bolt to catch some more threads at the bottom of the hole. You don't need a whole lot of thread to accommodate the 17ft lbs. General rule of thumb is if you have a 1/4 in bolt you need a minimum of 1/4 worth of threads, so on a 1/4-20 bolt that would be 5 threads. Hope that helps.
#5
You may be able to get a slightly longer bolt to catch some more threads at the bottom of the hole. You don't need a whole lot of thread to accommodate the 17ft lbs. General rule of thumb is if you have a 1/4 in bolt you need a minimum of 1/4 worth of threads, so on a 1/4-20 bolt that would be 5 threads. Hope that helps.
I believe the bolt for the case is 5/16 fine.
Last edited by RidemyEVO; 02-15-2011 at 10:52 PM.
#7
Trending Topics
#9
Nope not too late. All day today at work I was thinking of different ways to go about this. I was thinking of using a bottoming tap and heli coil , getting the heli coil to the bottom wouldn't be a problem nor drilling out the old threads, I'm just not so sure I can get a tap that would be long enough to get to the bottom. I'm also thinking if its possible and the cam side case allows it, to drill right through and use a threaded rod or nut and bolt.
#10
After giving a great deal of thought to the situation I decided to pull the bolt back out, strangely enough there is quite a bit of motor oil on the bolt. So I got the vernier calipers out to measure the hole depth compared to the bolt depth and just as I thought the shaft and threads of the bolt is actually about 3.50 inches the hole depth is about 3.75 inches so I think I now have a couple options, I can try red lock tighting in a a stud about 4.25 inches and put a washer and nut or try a longer bolt. I may get lucky enough that when company that manufactured the cases drilled and tapped the holes they tapped right to the bottom.
I was also thinking to go get a helicoil kit for the bolt thread size and get a 4.5 inch long drill bit if they exist to drill the hole for helicoil, but I'm thinking stud might be a better direction to try first.
Any thoughts?
I was also thinking to go get a helicoil kit for the bolt thread size and get a 4.5 inch long drill bit if they exist to drill the hole for helicoil, but I'm thinking stud might be a better direction to try first.
Any thoughts?
If you go the stud route flush the hole w/ contact cleaner and use green loctite it a bit thicker and stronger. Good luck.