SpitfireS

This is just a picture of the bolts.

How much thread is still inside the frame?
If you drill through the part in the nut and weaken it enough to make it move you still have the top part to get through the nut.
Tricky.
Or turn it through the nut and try to get it out through one of the holes.
Either way, you can't get the bolt flush with the frame before drilling because you'll have noting left to grab & turn it with.
Btw.. drilling in the center is IMO not absolutely necessary, a little off center works too.
Once you start to get to the edge, using larger drills, the leftover steel will collapse making room for the rust.
And the leftover steel gives you something to grab.

You'll need special long drills, the average 6mm drill is maybe 4" long and the usable part only 3"
The center of the bolt is usually softer and IMO the bolts aren't hardened at all, just tough strong steel, you'll be able to drill through it.

Maybe, like mentioned in the other post, weld a bolt onto it so you have a hex head again.
The heat from welding and some extra heat might loosen the rust and make it move.
Sometimes rusted bolts get going if you hit them on the head, lengthwise I mean.

A rusted bolt is easier to work on than a seized stainless steel one.
They are welded together.

Good luck and take & post pics if you can!



Off topic @ bpaspi: I have the same thing with the pictures.
It looks like the US online car part sites are blocking EU IP's, maybe they go tired answering questions about shipping to Europe.
If you use a US based proxy that will hide your EU IP you'll be able to acces the sites again.

marcucci

Thanks for the pic SpitfireS. That's exactly what I'm talking about. Sorry that my pics aren't showing up, they are just linked from Majestic Honda's (http://www.hondaautomotiveparts.com) site. They're convenient for me since they have the parts images linkable, I had no idea they simply blocked non-US IPs.

bpaspi, I don't have any exposed threads to grab onto. The bolt broke with at least 2-3" inside the bolt hole, just about flush with the unit body (slightly inside the hole).

Also, I am certain rust is not the issue. The car is a 2001, but here in North Texas rust is not an issue at all. The humidity is low and there is no salt on the roads in winter. The car was well-maintained (aside from these bolts) and has no rust anywhere on it. I fear that the bolts were either stretched from over-torquing during the last clutch job, or they were simply cross-threaded. Either way, I fear that the threads in the body are damaged.

But I think I'm a fool to not at least try drilling. I may have to invest in the proper bits, I have some metric bits but none in that large a size. I may have a English or "standard" (I suppose "standard" for you is metric ) size that is close enough. I think I have the right tap, but it may not be deep enough. Regardless, I will attempt it.

My plan of attack:

1) See if I can drill out the bolts w/subframe on the car. I think there is no chance of success for this with the subframe in place, but I want to try it. I should be able to determine this quickly, if I can center a drill and if I have bits long enough to do this.

2) If that doesn't work, I will have to remove the subframe and try it again.

3) If I can't drill them out successfully, I will attempt to weld on a stud in their place. This should be a very strong, maybe stronger-than-stock alternative to the original bolt. I have to check and see if the original bolt threads just into one location or two. I fear that there may be an additional threaded feature higher up in the frame (top of the "box") it threads into. If it threads into two locations then this might not be as strong as stock. If the stock bolt only threads into one area, though, I would imagine this would be a feasible alternative. If I mess it up, I just go on to step 4.

4) If that doesn't work, or I deem it to not be strong enough, I will need to cut out the affected unit body section and replace it. I have a donor through a friend who's willing to let me cut up his "spare" chassis he has purchased for a kit car project. This should save close to $800 in new parts from Honda, or me having to fabricate a replacement plate and nut. It should also maintain a stock appearance and functionality.

Thanks, everyone, for all the help and comments.

I did ping Billman but no response yet. I check with the person from the thread linked above that he was supposed to help, but he hasn't had Billman do it yet.

JDR159

Don't know how much room you have there, but Milwaukee Tools makes a magnetic base portable 'drill press'. These will 'clamp' down to steel (electro magnet) which really stabilizes the drill (you physically can't move the drill with the magnet on).

I'd try to rent one of these, and drill it out. With this setup, you should be able to drill out almost to the threads without damaging the frame threads..

rjones

If you can get the bolt out but damage the threads you can repair the threads with a helical thd insert or other type of thd insert. McMaster-Carr has serval types of thd inserts that may work.

http://www.mcmaster.com/#threaded-inserts/=5hiky0

wadzii

you should be able to remove the subframe w/o pulling the engine. support the engine with a jack and pull the subframe.

if you can see the nut through the access hole in the frame then id say drill it out, make the hole big enough to put another nut through there. Go find you a longer bolt and be done with it.

if you fubar the threads with the drill you could drill it one size bigger, get a bigger bolt and drill the holes in the subframe.

bpaspi

I don't think that 1 - 3 will work, because there are 2 nuts for every bolt: one on the bottom and one on top of the chassis arm.

when I understand #4 right you propose to weld another bolt / stud on the chassis as a substitute for the broken bolt. That will not be strong enough. The load is not transferred into the arm, it's concentrated on the weld.

You have access to the area from the wheel side of the chassis. You can cut a square hole with an chisel in the chassis to get to the nuts.

Stratocaster

Marcucci, have you considered using a borescope to inspect the same bolt location on the other side of the sub frame? That should reveal what the mounting structure of the bolt is, and what is any space is located behind the wall of the frame to assist in the removal, and if you can cut an inspection hole in the side of the frame rail to assist with the removal.

rossco

the best way to fix this is to just remove the subframe and support the enging/trans. you want to make sure you can get to the broken stud easily. i work at a honda dealer in oahu hawaii. we have had this happen numurous times on odyssey vans. hopefully part of stud is slightly sticking out still, we would grind down the broken stud perfectly level with the body. then center punch it. then drill it out while slowly increasing the bit sizes till the rest of the bolt is thin enough to pull the threads out. they come out like a spring, after finally drilling it out to the exact same size as the bolt size. don't go too big as to drill out the threads in the body of the car. also spray loads of penetrating lube. then finally we would rethread the hole, and like new again. i think this just happens to some of the cars because of the salt air. some people live right off of the beach. the bolt just breaks off because it is siezed in because of rust or corrosion. hope this helps.


p.s. if ever having this problem, best to spray penetrating lube first and work the bolt back and forth( tighten/loosen) till it frees up. before man handling it with a breaker bar. might save the bolt from breaking off. but sometimes sH!t happens.
good luck!!

CKit

That is really excellent advice!

Thanks for sharing your expertise.
I'll have to file this away in my "tips and tricks" memory file.

marcucci

I'm familiar with the drilling out process. I honestly forgot about a helicoil and I appreciate that reminder.

I have borescoped it and it appears that there is only one nut/threaded feature at the bottom of that frame rail. I can't find one on top, at least not as high up as the bolt will reach.

I'm not sure I can safely support the engine and remove the subframe, at least not doing that and having enough room to maneuver. We'll see.

Thanks again for all the comments/help. I'll take pictures as I go and post back w/results.