Wrong Headbolt Torque

400D Guy · Mar 15, 2012

I torqued the head yesterday to a new gasket, and went back this morning to recheck the torque. But, I set my wrench 25 lbs too much. As I was pulling the center stud, I thought something was wrong, and found my problem. The wrench didn't click however. So I'm assuming I torqued it up to about 20lbs over. I immediately let off on the torque a bit, checked the book and found I could go up to 135lbs from the 125 I had on all the other bolts. I then pulled them all to 135lbs, and the one I messed up on appeared to spin just a little short of when I overtorqued it.

Is this bad??

rustred · Mar 15, 2012

must be a 264 diesel. kinda confusing as to what your asking. what do you mean by "spun just a little"? is the one that spun taking torque? could be the stud is streching and ready to snap off.?? i can feel when threads are pulling or stud streching.

sflem849 · Mar 15, 2012

(quoted from post at 16:44:49 03/15/12) must be a 264 diesel. kinda confusing as to what your asking. what do you mean by "spun just a little"? is the one that spun taking torque? could be the stud is streching and ready to snap off.?? i can feel when threads are pulling or stud streching.

One of the "rack" hold down bolts did that on my MD.

400D Guy · Mar 15, 2012

Yes, it's a 264 diesel. I meant the nut turned a little when I retorqued it. They all did. And, they are all new studs and nuts.

I'm just wondering if overtorque on one stud by maybe 10 or so ftlbs is a bad thing. Plus, I relieved the torque a little on that same stud. So, it's torque was 125, then about 145, then 135.

Janicholson · Mar 15, 2012

That one is for sure going to need to be taken out
of the head. If it is a headed bolt, the head might
need to be removed. If it is a stud and nut, and
the bad threads are on the nut, or on the top
threads, the situation is much better in that the
stud can be removed and replaced W/O removing the
head. Tell us what you find. (even a few degrees
of rotation with no increase in torque is a failed fastener. If the block has pulled threads, it can be repaired with a threaded insert. (Helicoil is not the only system, Thread Serts is one other that provides great service. Jim

Allan in NE · Mar 15, 2012

Darned 'M police' are gonna get ya for sure! :>)

Allan

robgIN · Mar 15, 2012

If they are all new fastners you are probably ok. I can remember some shop manuals in the past saying if new head bolts to torque them then back them off one at a time and retorque them to get the stretch out of them.

Wrong Headbolt Torque

400D Guy

Member

rustred

Well-known Member

sflem849

Well-known Member

400D Guy

Member

Janicholson

Well-known Member

Allan in NE

Well-known Member

robgIN

Member

Similar threads