Cross Threading

[pajoka1234]

New to this site so Hi people .

I have a question as cant find any think on the internet about it so I thought I would come to you lot for advice as you all know your stuff.

Basically i have a situation where I was putting in the bolt for the coil pack and then about halfway 3/4 of the way through it has resistant but then goes easy again when turning it another turn and then goes in without any resistant and can tighten up with ease.

If it was cross threaded then would it be very hard to turn all the way from the point it starts resisting until the end by hand . I always do it up by hand first before I start using a socket and ratchet.

If it was to be cross threaded , then if I was to take it back out and to put it back in again and then the point it starts resisting again would it still be hard to turn all the way through till the end of the thread

I'm guessing it could be dirt that is inside the female or male thread and the resistant would be only temporary as it going pass that part on the thread , i'm guessing when that happens and you go passed that dirt on the thread its fine as it goes easier again and no resistant until the end . Hope this makes sense and can get back to me .

[TooMany2cvs]

pajoka1234 said:

Basically i have a situation where I was putting in the bolt for the coil pack and then about halfway 3/4 of the way through it has resistant but then goes easy again when turning it another turn and then goes in without any resistant and can tighten up with ease.

That's not cross-threaded. That's just a bit of grot on the thread.

You've really got two choices - you can take it out and have a look, see if the threads are damaged. Or you can just forget about it and get on with life. If it's just retaining a coil pack, I don't think it's going to be too big a deal even if it is a bit compromised. I'm presuming it's not the ONLY fastener, either?

[pajoka1234]

It is only one , cheers for the advice . Can you or someone else explain to me though that if it was halfway 3/4 way down or anywhere on the thread, how would you know if it was cross threaded and not just dirt also would you be able to try it again like put it in thread would you still feel the same resistant Sorry to go on it just so I know in the future.

[IanCress]

Generally if it's cross threaded the further you screw it in the harder it will be to turn, as more threads get crossed.

As above, if it's in solidly then you have nothing to worry about.

[kambites]

IanCress said:

Generally if it's cross threaded the further you screw it in the harder it will be to turn, as more threads get crossed.

As above, if it's in solidly then you have nothing to worry about.

You wont get a cross-threaded screw more than about two turns in without being able to feel that something is very wrong, even with a ratchet. By hand you wont get it past about that point at all unless you're screwing it into a block of cheese rather than metal. Crossed threads will also stay stiff/get stiffer until the bolt comes out the other end of whatever it's screwing into.

[pajoka1234]

So basically what you are saying is that if it was cross threading then you would feel the bolt getting stiffer and stiffer as it tuned in your hand and then will be very hard move with your fingers.

If I was to take it back out and put it back in then would you still feel the bolt getting stiffer and stiffer or would it be alright .

And your also saying that if the bolt is down a bit or so and has resistant but then on the next turn it goes easy again and can do it all the way up then its fine.

[PositronicRay]

pajoka1234 said:

So basically what you are saying is that if it was cross threading then you would feel the bolt getting stiffer and stiffer as it tuned in your hand and then will be very hard move with your fingers.

If I was to take it back out and put it back in then would you still feel the bolt getting stiffer and stiffer or would it be alright .

And your also saying that if the bolt is down a bit or so and has resistant but then on the next turn it goes easy again and can do it all the way up then its fine.

It's when it won't tighten that you have to worry, then it's stripped.

[E-bmw]

There was me thinking cross threading was when someone put a question about brakes in the engines section.

[pajoka1234]

So basically when it cross threading it trying to create a new thread inside the female thread which causes the stiffness as it stripping away the metal inside around the original thread in the female thread and also causes the male threads to be stripped as well.

[TooMany2cvs]

Cross-threading means that the two sides of the bolts thread have picked up on different threads on the nut, so you're going in at a wonk. If you continue to force it in, something's got to give - because clearly it can't continue to go in on the wonk for long. It'll go very stiff, but if you continue to force it, you'll muller the threads. One side will try to pull across to the thread it should be in, but in doing so will bend over the peaks of the thread. As you continue to forcibly wind it in, that damage will cause more damage all the way down.

[pajoka1234]

Thank you for all getting back to me appreciate your help


So if the bolt had a slight resistant, then on the next turn it was easy to turn and then all the turns all the way up to the end was easy then it's okay or if the same situation occurred again on the same bolt and still went easy on the turns afterwards it's okay until the end.


Or on the other hand if the bolt was still resisting on each turn after starting to feel the resistance on the thread on the turn I felt it on . I am starting to cross thread

Last question promise haha

[StoatInACoat]

Having cross threaded a coil pack bolt in an aluminium head what you will probably notice is that the bolt wont tighten up enough to retain the coil pack properly and then when you take it back out to find out why it'll be covered with aluminium swarf. The more you try to tighten it the looser it'll get until the thread in the head is completely gone as the bolts will be made from a harder material than the head. Cross threading a bolt feels obviously wrong when you're tightening it which is why you feel such a spanner if you ignore your instinct and do actually manage it.

If that does happen then panic not and buy a helicoil kit.