Timing Belt Tensioner Broken Bolt

[JakeRenshaw89]

Hey all!

First post here but love seeing all the help from the community so I had to join!

I bought a 2001 LC a few weeks ago with the intention on building it up to be a fun car as well as to keep some miles off my 2022 F250 Superduty.

Anyhow, I am in the process of changing out the timing belt and water pump as well as some other goodies and everything was going well until I came across a cross threaded bolt on the timing belt tensioner and the bolt head broke off leaving about 2/3s of the bolt still in the tensioner mount.

I can’t get a tap and die set in there as there isn’t sufficient room. I tried an extractor set to no avail as you can see.

What other options do you guys suggest? It’s such a tight area with very very little access…

 

[Bisho]

I think you can remove that cover so you can work on it on the bench. I don’t know what can of worms you get into, though, as a result.

 

[JakeRenshaw89]

I think you can remove that cover so you can work on it on the bench. I don’t know what can of worms you get into, though, as a result.

View attachment 3738925

Thanks, Bisho! That was my fear, what happens when I remove that cover… which was my last resort but I’m not sure if it’s my only option at this point.

Assuming it’s a bad idea to just run 1 of the 2 bolts for the tensioner? Ha

 

[Bisho]

Thanks, Bisho! That was my fear, what happens when I remove that cover… which was my last resort but I’m not sure if it’s my only option at this point.

Assuming it’s a bad idea to just run 1 of the 2 bolts for the tensioner? Ha

Yes, it’s a bad idea.

With a right angle attachment you may be able to drill it out. Tapping the aluminum should be pretty easy, but the whole thing is fraught with peril if it gets mucked up.

 

[juicemode]

I think the “cover” is actually the oil pump and i think to remove it requires both the lower and upper oil pans be removed also. Not 100% sure. It would be nice to remove to either replace or drill and tap.

 

[JakeRenshaw89]

Thanks guys. I might pick up a right angle drill or attachment and try and drill and tap it where it is now.

 

[2001LC]

I've had a lot of luck, drilling out bolts. By starting with very small bit and then drilling with larger and then larger bit, always working to center. Drilling to just the right size, so that I can clean out threads with a chase. Then reuse factory stock bolt.

But this may be to damaged already. If so. Drill and use a time-cert made for aluminum. Centerning is key.

If that fails, get a new oil pump. Pick-up tube must come off, so both pans must also.

 

[JakeRenshaw89]

I've had a lot of luck, drilling out bolts. By starting with very small bit and then drilling with larger and then larger bit, always working to center. Drilling to just the right size, so that I can clean out threads with a chase. Then reuse factory stock bolt.

But this may be to damaged already. If so. Drill and use a time-cert made for aluminum. Centerning is key.

If that fails, get a new oil pump. Pick-up tube must come off, so both pans must also.

Thanks! That’s my plan, essentially stair step up on bit sizes to bore the hole out. I’m just not sure I can squeeze in a thread chaser but I’m going to try a drill/tap bit with the right angle attachment and hope that works.

 

[2001LC]

Thanks! That’s my plan, essentially stair step up on bit sizes to bore the hole out. I’m just not sure I can squeeze in a thread chaser but I’m going to try a drill/tap bit with the right angle attachment and hope that works.

Good luck!.

As I "stair step". I only drill a dimple. Working to better center each dimple. Until I feel I am dead on center, I don't drill/cut deep or punch through.

Very good drill bits, Patient and good Lighting, are a must.

Whatever time it takes, is better than pulling oil pans & pump.

 

[Malleus]

I've given up drilling out broken bolts. A carbide burr on my Dremel works as fast and is much more controllable, and I can get it into anywhere I need to be. Once I get enough out to have only a thin wire let, I grab it with needle nose pliers and unwind it from the hole. I have yet to damage any thread using this method, and it has the added benefit of saving weldnuts that I typically broke loose, due to pressure on the drill.

 

[2001LC]

I've given up drilling out broken bolts. A carbide burr on my Dremel works as fast and is much more controllable, and I can get it into anywhere I need to be. Once I get enough out to have only a thin wire let, I grab it with needle nose pliers and unwind it from the hole. I have yet to damage any thread using this method, and it has the added benefit of saving weldnuts that I typically broke loose, due to pressure on the drill.

I need to try that.

 

[Malleus]

I got tired of the drills walking off the centerpoints, which I could never get exactly centered, and I thought I'd try to create a "better" centerpoint with my Dremel.

As I had it in my hand I realized I had the only tool I needed, so instead of trying to "centerpunch" with the carbide burr, I just drilled into the screw with it. I was done in the time it would have taken me to centerpunch, centerdrill and drill with the smallest size drill I had planned to use. And I didn't break any 3/64" drills (which was getting old anyway).

The carbide burr lets you move around inside the drill cavity you create, so there's never any chance of off-drilling and eating into the threads. My burr lets me get into an 8-mm bolt easily; there's only one potential 6-mm bolt (and that's on an 80) to worry about, so this method handles every problem I've seen so far.

 

[97 AZ LC]

The carbide burr lets you move around inside the drill cavity you create, so there's never any chance of off-drilling and eating into the threads. My burr lets me get into an 8-mm bolt easily; there's only one potential 6-mm bolt (and that's on an 80) to worry about, so this method handles every problem I've seen so far.

Can you post a picture of this carbide burr, or give us a part number? Thanks.

 

[Malleus]

Yeah, give me a minute to find it.

 

[Malleus]

Any of these will work, I bought the Dremel brand because it's what HD had on the shelf:

 

[Malleus]

I should have mentioned that I also have a flex shaft for my Dremel, so I can hang the motor out of the way and get into pretty much anywhere I want. I can't imagine using it without the flex shaft.

 

[AARONTLC]

I should have mentioned that I also have a flex shaft for my Dremel, so I can hang the motor out of the way and get into pretty much anywhere I want. I can't imagine using it without the flex shaft.

I have used my Dremel for so many "tough" situations. I broke a 6-32 tap in the slide of my Glock 19. I used my Dremel and a diamond burr to lightly chew the HSS tap and it just fell away. Flex shaft is a great tool!

 

[JakeRenshaw89]

Just to report back, I fixed the issue by drilling it out with impact bits using a right angle drill attachment. PITA to say the least! But I was able to tap it and get some threads in there and used a heli-coil since my buddy swears by them. I would like to try a thread sert in the future as those seem like a more long term solution. But I believe this particular bolt only calls for like 15ft lbs so I’m not worried about it holding up long term.

Thanks again for all the help fellas!

 

[2001LC]

19ft-lbf.