Front engine mount bar stud replacement!

[wprater]

My case had the top left stud hole filled with JB Weld. This is where the support bar stud should be. I chiseled away the JB Weld and have been trying to drill it out, so I can re-tap the hole.

Not having much success, and it looks like this solid aluminum (like a case plug) vs JB Weld.

What options do I have at this point? Do I keep drilling and hope I get to the threads? I was planning to just chisel out the front part and then clean/re-tap the M12 hole.

Getting a bit nervous now and wanted to get some thoughts from the seasoned rebuilders out there!

Thanks!

[boosted79]

So the JB Weld is gone and you are into just metal now? If so I would try a spiral EZ out along with a little heat on the case.

[wprater]

Its actually Loctite 9340 Hysol, but same general compound as JB Weld?

But you're correct, it looks as if the epoxy is gone, but why is there solid metal underneath it? Broken stud?

I'll look for better extraction tools like the spiral EZ out. thanks!

[boyt911sc]

Originally Posted by wprater

Its actually Loctite 9340 Hysol, but same general compound as JB Weld?

But you're correct, it looks as if the epoxy is gone, but why is there solid metal underneath it? Broken stud?

I'll look for better extraction tools like the spiral EZ out. thanks!

Start using the correct size drill bit for the stud extractor. Take your time and make sure the drill bit is straight and centered to the broken stud. Use a small pilot hole and enlarge as needed. Be very careful not to break a drill bit in the process and leave it stuck.

Tony

[wprater]

Good points.. thanks.

Anyone know how long this stud is here?

[boyt911sc]

Originally Posted by wprater

Good points.. thanks.

Anyone know how long this stud is here?

If my memory serves me right, the threaded piece for this stud is about a little bit over 1". You don't need to drill through the stud. Depending on the type of stud extractor you have, 1/2" deep might be good enough to be able to get the stud out. Applying some heat will help loosen it too. Keep us posted.

Tony

[tharbert]

May want to try a left handed drill bit too.

[wprater]

Will keep you posted! Going to try and get some tools today before I out for a week.

You think it's wise to remove/replace the other studs for the mount bar while Im in the mood?

[gtc]

If it ain't broke...

[boosted79]

For sure. Why would you want to try to eff something up that isn't? Been there, done that.

[wprater]

I hear you! Not much luck so far. The extractor they sold me is not working very well, and these pilot holes Im drilling are starting to tunnel and Im worried they will become crooked.

Here is a new shot of my progress... not looking very good

[Walt Fricke]

That looks like a good extractor.

This is a very odd situation. Those studs don't have a habit of just breaking off. And why in heaven's name would anyone, after one did, fill in the surface with epoxy?

If you can get the broken part out, you can use a Helicoil or other insert (requires drilling an oversized hole and using the tap specified for the insert)if you have damaged the threads in the process.

But while that works just fine on the transmission to chassis bolt hole when you have buggered up and cross threaded the threads (because you have the hole to pilot your drill), it looks like you have drilled your hole off center? If you end up with an insert off center, you are going to have to alter the engine mount so it will line up. And this bolt one of the long ones which goes through a tube in the mount. Be quite a project to move that tube.

But maybe you are centered? If so, try using a thicker drill? And keep going until you can see threads start to emerge. And if you still can't pick out the remains, or have damaged the threads, you have the insert option.
On the brighter side, I just measured a case, and it is at least 3.5" thick, so you won't be drilling into anything you shouldn't.

[tharbert]

Originally Posted by Walt Fricke

...On the brighter side, I just measured a case, and it is at least 3.5" thick, so you won't be drilling into anything you shouldn't.

That right there is golden info!

[boosted79]

If you can't remove it with the extractor then bolt the engine hanger on with the good studs and use that as a pilot to drill it out, you might have to have a pilot bushing made. I've had better luck with the spiral ez-outs. As you turn them CCW they bite deeper due to the left-handed flutes.

[boyt911sc]

Originally Posted by wprater

I hear you! Not much luck so far. The extractor they sold me is not working very well, and these pilot holes Im drilling are starting to tunnel and Im worried they will become crooked.

Here is a new shot of my progress... not looking very good

Use the right tool for the job. The one you have won't work like an EZ out left hand spiral as suggested by Boosted and you probably ruined the hole already. Or a left hand drill bit as earlier recommended. Google for 'screw extractor'. There are several models or types you could choose from that will do the job.

Tony

[wprater]

Originally Posted by boosted79

If you can't remove it with the extractor then bolt the engine hanger on with the good studs and use that as a pilot to drill it out, you might have to have a pilot bushing made. I've had better luck with the spiral ez-outs. As you turn them CCW they bite deeper due to the left-handed flutes.

Good idea. Off to Boston.. back on Monday and then I'll try a new extractor. I suggested the spiral, but the harsware store guy said he's had better luck with straight edge. Should have just gone with my gut and what you guys suggested (silly novice, me.)

Im confident I'll get this fixed.. lots of sweat and swearing later.

Thanks!

[wprater]

Originally Posted by Walt Fricke

That looks like a good extractor.

This is a very odd situation. Those studs don't have a habit of just breaking off. And why in heaven's name would anyone, after one did, fill in the surface with epoxy?

If you can get the broken part out, you can use a Helicoil or other insert (requires drilling an oversized hole and using the tap specified for the insert)if you have damaged the threads in the process.

But while that works just fine on the transmission to chassis bolt hole when you have buggered up and cross threaded the threads (because you have the hole to pilot your drill), it looks like you have drilled your hole off center? If you end up with an insert off center, you are going to have to alter the engine mount so it will line up. And this bolt one of the long ones which goes through a tube in the mount. Be quite a project to move that tube.

But maybe you are centered? If so, try using a thicker drill? And keep going until you can see threads start to emerge. And if you still can't pick out the remains, or have damaged the threads, you have the insert option.
On the brighter side, I just measured a case, and it is at least 3.5" thick, so you won't be drilling into anything you shouldn't.

It should be mostly center. The edges are chamfered slightly, which makes it look off-center. I'll be double checking and try to trim the edges and make another pilot if not.

I also like the idea of using the housing with a pilot bearing to be certain I can drill it out nice and straight. Perhaps even a side mounted drill press?

I think it may event be possible to retread to an M12 and fit the stud thorough the housing carrier as well..

Will be doing more due diligence on Tuesday after I return..

Thanks for all the help and support guys, will be keeping you updated.

Cheers!

[cgarr]

I would just drill out all the steel, if there is an easyout broken off in then get it with a carbide burr, clean it all out, weld it up and re-drill and tap the hole.

[Walt Fricke]

Craig - not everyone has a TIG in his garage. I think a Helicoil or Case Saver or the like would do fine. I've got some of those in the case to hold the bolts or studs joining the engine and transmission, and they do the job fine, so should do so here. Of course, those were not the result of a stud breaking off.

In thinking about a pilot to get drills straight, what about the motor mount itself? The other three studs should hold it just right, and it is a longish tube.

[wprater]

back at it with a new spiral extractor. its being very stubborn, so its hard to even rotate the thing. possibly because the pilot is slightly off center, its really hard to tell.

getting a welder in the shop to fill in the block and start over might be my best option at this point. Im not sure this damn stud is going to budge.. will report back end of day if I have good news to share!