Replaced Lower Head Studs

jjone20 · jjone20's Garage

I've read all I could get my hands on concerning this topic, and searched the archive. I think I want someone to tell me it's OK. I got my lower head studs out, and then chased the threads with the specified tap. Putting in the new studs (test fit first) they seemed to spin in easily. OK, I figured. But I double-checked the tap I used to make sure I hadn't screwed something up - it just seemed too easy. I installed the studs with red Loctitite to the required height, and everything seems fine. But now I read in the archive about NOT using a tap, or using a specific kind of tap. Do I proceed, or start over?

Eagledriver · 10-15-2007, 07:34 PM

Well as you surmise you probably shouldn't have used the tap. I wouldn't worry about it too much however. The main thing is that they are installed to the correct height. The red loctite should hold them inplace. Once they are torqued up they shouldn't move. There is really nothing you can do now to tighten the holes up unless you were to install time-certs or case-savers.

-Andy

jjone20 · jjone20's Garage

Thanks, Andy. Anyone else care to weigh in? Wayne?

cgarr · cgarr's Garage

Was the stud loose in the hole? in other words, when the stud was threaded into the case and before you tightened it up could you still move it? As you found out, a thread chaser not a cutter should be used.

jjone20 · jjone20's Garage

One of the studs would wiggle in the hole, the rest just spun in with very little resistance. Once they were snugged up to the right height, they seemed fine.

hcoles · 10-17-2007, 06:43 AM

I did the same thing... used a regular tap which is not correct. You are supposed to use a cleaning or thread repair type tap. Anyway I suggest you are fine. I've got 15k+ miles on my engine after using the wrong tap and cleaning out the threads 10 times with the tap and brushes and brake cleaner and then using the red Loctite.
I'm no expert.. this is just what I did..

BTW - I saw on I think it was the Sears website... a full set of metric and english thread repair kit for very low cost... I got one and have used it a number of times. Works great. A neighbor came and borrowed it and fixed his messed up boat trailer wheels studs.