Crankshaft Threads Stripped 2.2L

[buffbuh]

Figured out how to start new thread. Had to go to top of thread group.

 

My Harmonic Balancer came off, and left the crankshaft threads stripped. I'm planning on using Time Sert or Heli Coil to fix the problem. I'm not sure if the Time Sert will seat in far enough before seating.

 

I couldn't seem to find any thread on USMB describing someone doing this. Usually people have a key problem - mine was still in there unharmed - just the threads inside got stripped - that's where the damage happened. Has anyone out there done this before (Heli-Coil or Time Sert in Crankshaft)?

 

I will be using new timing gear, new Harmonic Balancer (should I get aluminum pulley, or stick with rubber-separated), new belt - drill, insert "sert", use blue loctite, tighten down to maybe 135 ft/lbs.

 

1997 2.2L Subaru

[GeneralDisorder]

Yeah I've never seen that.

 

I would use a heli-coil myself.

 

Don't go with the aluminium pulley - get a stock one. They can be had with or without rubber - most of the earlier 2.2's were solid steel.

 

I wouldn't loctite the bolt either. The rotation of the engine tends to tighten them so as long as you get them tight enough not to back out you will be fine.

 

GD

[ShawnW]

The threads are so sunk down into the crankshaft I don't think it will work to insert it. Theres not enough material around the edge to get one in there.

[buffbuh]

That's right, upon further investigation, I found that the crankshaft bolt broke off about where the threads start.

 

The good news is probably no need for tapping and Heli-Coil.

 

I have to drill the left-over bolt piece with drill bit and use an easy-out.

 

I also now have a better view of the key. The key is bent over, and the key way may be compromised/damaged a bit. I'll update and include pictures later. Hopefully it's repairable.

 

Buffbuh

[GeneralDisorder]

Don't use an easy-out - it will break off and you'll be in a worse situation. Get a set of left-hand drill bits and make sure you center punch it VERY accurately.

 

GD

[buffbuh]

Good advice, GeneralDisorder! I did use right-handed bit at first (didn't have left-handed bits). I used a drill "guide" (like a long spacer that fit inside the crankshaft bolt hole and a drill could then spin inside the spacer) to make sure I got pretty centered. Then I tried using an extractor (easy-out). I tapped it in with a hammer - got a good bite. Just used hand to turn it, not all my strength. It wouldn't come out, and I didn't want to break it.

 

So, I decided to go with a bit a size bigger. I had bought the 10-piece Hanson Left-Handed bit and extractor set. Left-Handed bits sounded a lot better. So I got the next size up bit, went to drill the hole bigger, and that Left-Handed bit just took that sucker right OUT! YEAH!

 

Then I read your post...

 

Now to assess the key-way damage.... see what I can do there. More to come... pictures later ...

 

Buffbuh

[Gloyale]

I would try to chase the threads with a tap first. It seems unlikely to me that the entire length of threads is stripped, probably just the first few got buggered when the bolt backed out far enough.

 

The keyway can be repaired by JB welding the key into it. Or, you can weld it up and grind it down to fit.

[GeneralDisorder]

It's pretty amusing how often broken bolts will just turn right out like that - basically all the tension was being applied by the head of the bolt - once that broke off the threaded part left in the crank was under no tension at all. I've seen this dozens of times. The left-handed drill bit's will often grab and spin the broken section right out.

 

Rust is another issue entirely - different from breakage due to overtorqued or stretched bolts. I still use my left-hand bits but I have much better luck with welding a nut to the broken section - along with liberal application of penetrant, etc the heat from welding will often get them loosened up.

 

Broken/rusted fastener extraction is an art-form all to itself - I like to think I'm pretty good at it but I know the east coast and midwest crowd here has more experience than I do .

 

GD

[buffbuh]

I used a hole-chasing like wire brush and Berryman B-12 carb cleaner to clean the threads, then my new bolt just went right in. I don't know if it needs to be chased with a tap if the bolt goes right in nice. ???

 

I do plan to use JB Weld on key and key-way. I don't have a welder, and no welding experience.

 

I'll keep you all posted. Thanks for ALL the input.

 

Buffbuh

[idosubaru]

pat yourself on the back for not proceeding with the ezout. success with those is anecdotal when you see what happens when they're used for real work.

 

GLoyale got it - chase the threads, my bet is you'll be fine. if there are any crank bolts that are longer than others i would get one. there are likely to be deeper threads than what the original bolt uses. i've done that multiple times too in blocks and such - longer bolts will reach unused and clean threads, giving you more margin. not sure you have any choices though with the crank bolt but thought i'd check.

 

like GD said, in the rust belt thread repair is just what you do when you really get into car work. i repaired no less than 4 different sets of threads yesterday on a friends truck. called in the morning.....somethings not right....then later again that day again. awesome. and it's a like a 2002.

 

anyway - throw your ezouts away. they will seem to tempting one day and they're totally worthless for automotive stuff. bottom line is this - anything that comes out with an EZout will come out with some other method that's far less problematic or disastrous. if they come out with an ezout - then it wasn't a very difficult removal to begin with.

 

left handed bits are my favorite. they're just hard to find good quality ones as no one stocks them. the cheap chinese harbor freight specials dont' hold up to hardened metals well. best to order ahead and have them handy but most folks need them *now* when they need them.

[buffbuh]

Cobalt is a material good for drilling metals - I read even better than Titanium bits because the Titanium are usually Titanium "coated", so the coat can wear off, and then you're left with a steel bit. Cobalt bit is Cobalt through and through.

 

Irwin Hanson Set 11119 comes with 5 different sized ez-outs and 5 corresponding Cobalt Left-Handed bits.

 

Two local NAPA's both had them in stock for virtually the same price I could get them online. No other auto or hardware place I called had this set - some could order it, others couldn't order it at all (not even Sears).

 

Individual Left Handed Irwin Hanson cobalt bits can be bought at LOWES. If you only need a couple of bits, I'd go that way. If you want all five sizes, get the set.

 

But since you know where to get them right away now - no hurry!

 

I hope this kind of information is OK to post ... let me know if it's not.

 

Buffbuh

[vasy]

Never used a left-hand drill bit before so I need to ask this - am I supposed to set the drill in reverse so that the bit spins counter-clockwise?

[johnceggleston]

Never used a left-hand drill bit before so I need to ask this - am I supposed to set the drill in reverse so that the bit spins counter-clockwise?

 

yes

Edited November 2, 2010 by Qman

[buffbuh]

(Set drill in reverse to use Left Handed bit.)

 

I went to two places to size up this crankshaft bolt. The thread is 1.5mm, but it doesn't fit M12 or M14. Is it M13 ???

 

So I can't make a home-made harmonic balancer installer for this, as it is not a standard size. Grrrr....

 

What have any of YOU used to seat your harmonic balancer? It is not recommended to put all that force on the crankshaft bolt. That should be installed AFTER seating the harmonic balancer, then torqued to spec, right? (Spec per discussions on this board is not enough - some have torqued from 100 ft.lbs. to 140 ft.lbs.)

 

Buffbuh

[GeneralDisorder]

The EJ pulley/balancer's are not an interferance fit - you should not have to use anything but your two hands to slip it over the crank nose. If it's not fitting then there is a burr or corrosion, etc. Inspect carefully.

 

GD

[buffbuh]

OK - I shouldn't have a problem there then, I just need to get the key out and timing gear off.

 

I guess I better find that manual. I need it for timing instructions anyways.

 

I finally found a similar thread to mine with similar problem.

 

http://www.ultimatesubaru.org/forum/showthread.php?t=49495

 

They mention Denver Colorado's swingauto "pin" solution. It seems that would compromise harmonics - hole drilling, pins and such. And it seems to me all that it does is keep the balancer and timing gear aligned. It still seems (looking at the pictures) the load is on the key and key-way within the timing gear. I suppose the pin solution only helps if the key and key-way are damaged on the balancer side of the key-way, but the other half of the key-way where the timing gear is at is OK still.

 

I still have yet to get the timing gear off and assess the total key-way damage.

 

Pictures so far:

Subaru 2.2L Crankshaft Bolt Extraction

 

Buffbuh

[GeneralDisorder]

Getting the crank timing sprocket off can be a real biotch. I've dealt with fretted sprockets before - last one I broke two of the crank sensor tits off before it came off (not a big deal - plenty of spares around) - took 45 minutes of working it to get the sprocket off - that's with the engine out of the car on a stand . The key was shattered and a peice of it resides inside the sprocket to this day - sitting on a window-shelf-of-shame in my garage .

 

GD

[buffbuh]

This timing gear has two threaded holes for pulling-off purposes. But the face of the timing gear was shaved, so the first thread(s) are stripped. I guess I need to tap it, but I'm not sure of the size - is it M8/M1.25?

 

Buffbuh

[GeneralDisorder]

Most likely 8x1.25 yes.

 

GD

[idosubaru]

i wouldn't over think the keyway and details. i've reinstalled them before with just the bolt, no keyway in place, only the bolt holding it. works just fine if it's tight enough, never had a problem doing that. i've also seen folks spot weld the harmonic balancers back together...or use self-tapping sheet metal screws to hold the two halves together! not that i recommend any of those ideas, but i'm just saying i wouldn't stress about it too much from such a technical perspective.

 

do the best you can, make the crank and bolt threads clean so they engage perfectly smoothly and make it TIGHT. you'll be golden.

 

1.25 is the pitch, not sure the diameter but i'd lean heavily towards your hunch of M8. if you need to size it - you can often just "borrow" a bolt from the engine bay - like memory tells me the fender bolts on top are easily accessible and M8x1.25.....either way, find a bolt that fits the thread so you have somethign to take with you to the parts store and match up.

 

or if you have a die set, just use a die to figure it out?

[Qman]

i wouldn't over think the keyway and details. i've reinstalled them before with just the bolt, no keyway in place, only the bolt holding it. works just fine if it's tight enough, never had a problem doing that. i've also seen folks spot weld the harmonic balancers back together...or use self-tapping sheet metal screws to hold the two halves together! not that i recommend any of those ideas, but i'm just saying i wouldn't stress about it too much from such a technical perspective.

 

do the best you can, make the crank and bolt threads clean so they engage perfectly smoothly and make it TIGHT. you'll be golden.

 

1.25 is the pitch, not sure the diameter but i'd lean heavily towards your hunch of M8. if you need to size it - you can often just "borrow" a bolt from the engine bay - like memory tells me the fender bolts on top are easily accessible and M8x1.25.....either way, find a bolt that fits the thread so you have somethign to take with you to the parts store and match up.

 

or if you have a die set, just use a die to figure it out?

 

Did you really just tell him to install the crank gear without a keyway? Unbelievable!

[buffbuh]

Subaru Crankshaft Bolt Extraction and Timing Gear Removal

 

As I suspected, the key-way is damaged, slanted on the edge, leaving a gap when the key is inserted.

 

Option 1: JB Weld.

 

Option 2: Widen key-way, and insert custom key. Maybe use JB Weld, too.

 

Option 3: Tig weld and grind key-way to original size, use original key.

 

We're looking at Option 2 right now - get wider key, and modify it to fit new widened key-way AND fit balancer & timing gear.

 

More pictures to come as we progress.

 

Buffbuh

[idosubaru]

Did you really just tell him to install the crank gear without a keyway? Unbelievable!

No, I meant the crank pulley, which is why i was talking about the harmonic balancer and spot welding and screws. Sorry. it wasn't clear in the beginning. I wasn't sure how far it was damaged or what was easily repairable/not.

[Qman]

No, I meant the crank pulley, which is why i was talking about the harmonic balancer and spot welding and screws. Sorry. it wasn't clear in the beginning. I wasn't sure how far it was damaged or what was easily repairable/not.

 

If you don't know the extent of the damage, ask. don't give advice based on an assumption. That is why things go from bad to worse. Listening to a long-time member guess at a how bad the damage is just not how it should be done.

[buffbuh]

A fourth way has been brought to my attention.

 

Option 4: Widen key way to get 90-degree side-wall, use original key, and a second modified key to fill in the gap and go flush with outer diameter of balancer. Use JB Weld to stick it all together.

 

Eric does a good job of summarizing different ways to approach and the way he chose to do it in the end (my new Option 4).

 

crankshaft_keyway_repair

 

Bryan