Fan Bracket Stud Question 5vz 3.4

I stripped a nut on a stud reinstalling the fan bracket on my 3.4 5vz. I torqued the nut on the stud and the bolt that holds the fan bracket above it to 38 ft lbs. The top bolt felt good and my torque wrench clicked at a comfortable feel. The bottom nut on the stud kept spinning. I took it out and it looks like the nut / stud connection is stripped since the nut is spinning in place.

I was concerned the stud may have stripped out the threads in the block, so I measured the depth of the hole for the stud and marked it on the stud. This is how close it got - roughly half way to bottoming out. The threads are sunk in the block. There couldn't be any more resisting torque to be gotten I'm assuming. Maybe if the stud was sunk to be bottoming out in the block? But threading it any further into the block felt like I was chasing the threads and I've had bad experiences doing that with a regular bolt.



So I tested the similar stud and hole that the other stud goes through the fan bracket and the power steering pump into the block. I got roughly the same result with both studs and the top bolt threading roughly the same distance into the hole before I felt like I was overtorquing the bolt / studs.

Here's the same stud in the other hole. Remember I've gotten roughly the same result with two studs and a bolt in each hole where they would not bottom out before it felt like too much torque.



So my question is, are these studs supposed to bottom out or do they generate enough torque for the nut on the other end by just having all the threads engaged in the block? Did the nut that stripped maybe just have bad threads from the last guy that worked on it over torquing it? Is that even possible while using studs? Sorry - I'm pretty nooby when it comes using studs vs bolts. Just to confirm, everything is spinning nicely and securely in each hole until the threads are buried and at about the same depth on each the torque increases to where I'm promted to stop. Thank you.

@mechanicjon @Torspd

 

It's possible your running out of threads on the bolt. If that's the case, that's as far as they will go in. Both ends of the studs have the same length threads?

 

Good call I checked for that - there's a few threads left. I also saw that the stud on the engine in my truck was in the same amount so I'm guessing it was just a stripped nut / stud from the last guy. I've been taking it easy and using hand tools for 99% of what I'm unbolting.

 

So I used the stud from my other engine and was surprised to find that even though it didn't get to 38 ft lbs, or at least I didn't keep turning it until it felt as snug as the top bolt that did, when I backed off the nut in disappointment, it didn't spin the stud like last time and unthreaded while the stud stayed firmly in the block.

I snugged the nut up again and now I'm considering whether I should leave it that way because it's in close to the recommended torque as per my calibrated arm wrench or to heliocoil it. Nervous about drilling a hole in my block to put a thread insert though. More tools would have to be purchased (better drill bits and a tap and die set), but the main thing is me wussing out over drilling lol. I also am on a tight schedule and the bracket is held on by two other big bolts / studs. Advice? Gracias.

 

Try wrapping some Teflon pipe thread tape on the stud and threading in. Cheap fix but this isn't a highly critical joint and its relatively easy to check on it occasionally.
Other option is some of the stronger loctite products to permanently fix the stud into the engine. If I recall that might be a problem when you need to do your timing belt in the future though.

 

Thanks for the ideas Mike, got my wheels turnin'

 

Was there maybe a little burr on the threads ??

Some grit got into the hole .

Different stud going into that hole

It does not take much to cause the threads to get tight