Broken Transmission pan bolts :(

[scrubolio]

Long story short, I broke quite a few transmission pan bolts off. (never take off rusty bolts when in a rush)

and luckily, once I got the pan off most of the leftover studs from the bolts were easy to get off using a vice grip...

of course except for these 3 bolts, now studs. Any help would be greatly appreciated!

1 stud has been mangled by my vice grip trying to get it off. I've backed it out a few turns but it seems stuck now. I sprayed PB Blaster on the bottom and top, tried to heat it up with a soldering iron (didn't do anything), dremeled a slot into it to use a flat head, the sides of the slot just broke off as I tried to turn.

Any other ideas?

2nd stud is recessed inside this protrusion. I tried using 3 different bolt extractors with no luck. In the end I drilled all the way through to the top and can feel the hole at the top but it still won't budge.

My guess is to use a bigger drill but size, but I don't want to mess up the threads more than I already have. The threads maybe a lost cause and I'll probably have to use a heli-coil type repair, but is there enough room to even insert a heli-coil?

3rd stud is coincidentally stuck inside the only other protrusion. I use this fancy ($$) tool and it seemed to be working, until it snapped off inside the stud...Its some super hard steel too, because when I went to use a punch to put an indent into it so I could drill another hole in it, my punch became dull...

I guess I need to get a harder set of punches and drill away. Any other thoughts?

Thank you for the help and thoughts!

 

[bigredmachine]

drill out the 2 that you can get out, ifrc 3/16 is just smaller than 6mm and thats the size that i would use when drilling out those bolts. as for the extractor my advice is dont use it on rusted bolts, they rarely work if the bolt is seized and are very hard but brittle. since were a little late on that one last time i had an extractor break on me i had to use a carbide burr to grind it and the bolt out of the oil pan replacing an oil cooler on a highlander.

i would try to grind out whats left of the extractor, itll take a lot of patience but it can be done. if thats not an option maybe you could cut that protrusion flush then try to drill it out

 

[NikP]

Most guys have luck with a welder and weld a nut onto the remaining stud. This allows you to get a wrench on things and the heat from the weld seems to help free up the seized threads. Other than that, it's drilling and tapping and I feel for you.

 

[scrubolio]

So I got lucky and unlucky

The “protrusions” I was referring to were just part of the gasket and they pretty much snapped right off with part of the seized bolt. On one I was able to use a Vice grip to get it off. The other I had to drill out, but not learning my lesson I used a different screw extractor they also snapped off inside the bolt. As mentioned, I used carbide burrs to slowly chip away then drilled and tapped.

The remaining bolt would not move with Vice grips and I eventually drilled it out but ruined about 1/4 inch off threads, luckily this was one of the bolts that has threads sticking out the top, I bought a longer bolt and put two lock nuts on top, hopefully these will keep it tight.

Thanks for all the help

 

[linuxgod]

Glad to hear you got it sorted out.

This thread is why I don’t recommend people drop the transmission pan to inspect the filter when doing normal fluid service. I do wonder if those who can turn those thru-bolts should remove them one at a time and apply a liberal amount of anti-seize, or thick marine grease or something

 

[scrubolio]

ya, now I remember why I have a transmission filter and gasket sitting in their factory plastic bags for my gx470 haha.

I thought hard about whether or not to apply anti-seize to the threads, but the Torque Test Channel did a good myth busting episode with an anti-seize test and the results were jaw dropping. using the anti-seize, there was almost 2x the bolt tension with the same amount of bolt torque.

Probably the best bet is to coat the bolts and exposed threads with fluid film, amsoil metal protect HD, anti-seize, etc.

 

[bloc]

I thought hard about whether or not to apply anti-seize to the threads, but the Torque Test Channel did a good myth busting episode with an anti-seize test and the results were jaw dropping. using the anti-seize, there was almost 2x the bolt tension with the same amount of bolt torque.

I see your point but these fasteners aren’t really the ones to worry about.. or at least personally, as diligent as I am about torquing nearly everything on my truck to spec, most of the 10mm head hardware doesn’t get that that treatment. I generally do M6 hardware by feel.

Huge difference than lug nuts, suspension pivot bolts, spark plugs, etc.

And the corrosion prevention and especially thread integrity preservation of anti-seize are hard to beat, all in one compound.