Cross threaded tensioner 4.0 SOHC

[rangerrex]

Nice. I managed to cross thread my front timing chain tensioner. I’m not sure what to do now. I’ve taken it back out carefully and threaded it back in a few times, no change. Anyone go though this?

2003 4.0 SOHC

 

[alwaysFlOoReD]

Not on that particular application. You have compromised the thread. Probably a thread repair kit would be best.

 

[rangerrex]

Not on that particular application. You have compromised the thread. Probably a thread repair kit would be best.

I looked into thread kits, problem is there’s an oil galley that goes through the threads and a repair kit would block it.

 

[Curious Hound]

How would the repair kit block the oil galley but the bolt doesn’t? The bolt threads into the female threads. So, there has to be metal there for female threads to exist.

 

[rangerrex]

How would the repair kit block the oil galley but the bolt doesn’t? The bolt threads into the female threads. So, there has to be metal there for female threads to exist.

Well, it’s not a bolt, it’s a hydraulic tensioner. So the galley feeds oil to the tensioner through a small hole. If it was blocked then the tensioner wouldn’t get oil. Let me know if I’m wrong

 

[Curious Hound]

Ok. I mis-spoke calling it a bolt. You’re not wrong. The oil port must remain open. So there is a male threaded portion of the tensioner that must thread into some female threads. There must be a way to repair the threads, both male and female. So, in the female threads, if there is enough metal to have damaged threads, then it seems there must be a place to insert thread repair somehow.

Does the oil port enter in the side of the tensioner? Or on the end of (I assume) the threaded part of the tensioner?

 

[superj]

back it out and force thread it straight.

dude, that sucks. you may be replacing whatever it threads into. i hate when that happens to me. god dang i hate it

 

[pentode]

Is the oil hole that feeds the tensioner in a recessed area just under the hex head? If so, and if you get to the point where you definitely can't salvage the existing threads, I think it shouldn't be too hard to install a helicoil - you'd just have to get your measurements right and install it a bit below flush. The bigger problem with that I see is somehow avoiding getting the oil passages full of metal chips, which is probably going to require some creativity.

If it were me I'd try really hard to see if you can get it threaded in to the original threads securely enough. Even doing that, still need to be careful of metal chips.

 

[rangerrex]

Hey guys, thank you for all your comments!

So I had ordered a tap on Amazon, M22 x 1.5. I then thought to myself, “No way I can make that work”. So I went to the junkyard and pulled a cylinder head.

Then I was cleaning up the head and the tap came. So I figured I might as well try it. I greased it up so the shavings would stick to it and not fall in the engine. And it worked! The tensioner is back in, perfectly flush, and torqued. I put a little bit of RTV on the washer so it has a little bit of a better seal. I just have to put everything back together and see if it gushes oil

Hopefully this post give some poor sucker out there some hope after they nuked their threads.

 

[pentode]

Good work! Let us know how it goes. I bet you'll be fine.

 

[JJMaine]

Hopefully it holds up, nice work! Quick question, you "primed" the tensioners before trying to thread them in? Ive read that priming them first will make them hard to install and increase the chance of cross threading them so I pulled the fuel pump fuse and primed mine using my engine as I was advised here.

 

[rangerrex]

Hopefully it holds up, nice work! Quick question, you "primed" the tensioners before trying to thread them in? Ive read that priming them first will make them hard to install and increase the chance of cross threading them so I pulled the fuel pump fuse and primed mine using my engine as I was advised here.

I did not, as you said that makes it harder. I put them in and primed them by holding the gas pedal to the floor and cranking the ignition. On ford modular engines holding the pedal to the floor while starting disables the fuel injectors, but still runs the oil pump and primes all oil components.

 

[JJMaine]

It is a tight space to work in to get those tensioners in so I can see how it would happen. I had the fortune (or misfortune) of having my engine out for head gaskets when I did my timing components so everything was right in front of me.

 

[bobbywalter]

that will fix all of your 4.0 problems....


and you will have new and improved 5.0 problems instead.

 

[JJMaine]

Intriguing! How easy is that to bolt in and what did it come out of? Mustang?