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What is behind the flywheel?


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Or technically speaking, in front of it, as mounted in the car. I don't see many illustrations.

 

My situation is that the Torx Plus 50 (maybe, most of my bits don't fit) bolts holding the dual mass flywheel to the crankshaft on my 2005 OBXT are holding on tight. I wanted to check my 6MT conversion before diving into the engine rebuild, but this is stopping progress.

 

I'm considering going ahead and pulling the engine, and looking at the following options:

 

1) Better access to the bolts lets increased leverage break the bolts loose, or

 

2) Better access to the bolts or portability of the engine allows access to heating methods that I don't have, breaking possible thread locker bond and letting the bolts come out, or

 

3) Increased portability of the engine lets me take it to a machine shop to let them do it along with the deck leveling I was going to have them do, or

 

4) I can break down the block with the flywheel attached and either take the crankshaft+flywheel to someone who can separate them, or just buy a new crankshaft. If I would end up with threadlocker to clean out or drilling out the bolt and retapping, I might not trust the new installation so much. Plus it looks like a new crankshaft is $300 +/- from a quick initial search, and with 8 bolts to remove it wouldn't take much shop charge per bolt to make a new crankshaft preferable.

 

For option 4 to work, there would have to be nothing on the block covered by the flywheel that would prevent me from disassembling to the level where the crankshaft could be removed. What is back there? Is it possible?

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have you tried an impact wrench?

 

Yes, cordless of 150 lb-ft and pneumatic of 550 lb-ft. I don't have a big boy 1250 or so lb-ft air wrench, but I'm concerned about shearing the heads off if the threads turn out to be locked. That may not matter if they need to be drilled out, or if I junk the current crankshaft.

 

ETA: The heat I can provide (and have) is the yellow bottle MAP Pro gas torch. Of course people will say it's not enough heat even for suspension work, but here there is a LOT of metal mass around the bolts, and access to the heads is through the little windows in the rear-most disk of the dual-mass flywheel, and it didn't do a thing for me. I didn't empty the bottle, so you can always say I should try heating it for longer, but I was getting uncomfortable with it.

Edited by subisubisu
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I bet you just cut the heads off of those bolts, and they come out by hand once you pop the flywheel off. That's been my experience every time I have a stuck one.

 

So do you think the binding is on the flange of the bolt head at the faying surface on the forward-most disk of the dual-mass flywheel?

 

It's not readily apparent how to cut the heads off through the little windows in the rear-most disk of the dual-mass flywheel, or how to split the disks of the flywheel. I don't plan to reuse it, so I could, if I saw how. And it's sounding like something better done with the engine out of the car.

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So do you think the binding is on the flange of the bolt head at the faying surface on the forward-most disk of the dual-mass flywheel?

 

It's not readily apparent how to cut the heads off through the little windows in the rear-most disk of the dual-mass flywheel, or how to split the disks of the flywheel. I don't plan to reuse it, so I could, if I saw how. And it's sounding like something better done with the engine out of the car.

 

That combined with the streching of the bolts putting extra pressure on the threads. Release that stretch and the pressure goes way down. I always have used a die grinder to get the heads off.

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That combined with the streching of the bolts putting extra pressure on the threads. Release that stretch and the pressure goes way down. I always have used a die grinder to get the heads off.

 

Interesting. I wouldn't have thought the bolts would be much stretched. The installation torque per the manual is pretty modest, and fastener theory is that the clamping force applied at installation is supposed to be the most the bolt ever sees.

 

But back to the thread topic - is there anything obscured by the flywheel that I would need to access in order to break the block down enough to extract the crankshaft with the flywheel still attached, if it comes to that?

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But back to the thread topic - is there anything obscured by the flywheel that I would need to access in order to break the block down enough to extract the crankshaft with the flywheel still attached, if it comes to that?

 

That would be extreme and not possible with the flywheel attached. To split the case to remove the crank you need to pull access plates behind the flywheel to remove the hardware attaching the connecting rods to the pistons. There is a plastic plug on the top of the motor for removing the torque converter bolts, put an extension or pry bar through the flywheel and through that hole to lock the flywheel and get your favorite breaker bar and or cheater pipe and give her hell. They will either break lose or eff up the bolts. I’ve never had them ruin the bolt, but if it does just grind the heads off and the rest of the bolt will come right out with no effort. They have big heads and enough surface area to cause the friction that keeps them tight. Since the bolts aren’t bottomed out, the threaded section will no longer have any tension on the threads.

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That would be extreme and not possible with the flywheel attached. To split the case to remove the crank you need to pull access plates behind the flywheel to remove the hardware attaching the connecting rods to the pistons. There is a plastic plug on the top of the motor for removing the torque converter bolts, put an extension or pry bar through the flywheel and through that hole to lock the flywheel and get your favorite breaker bar and or cheater pipe and give her hell. They will either break lose or eff up the bolts. I’ve never had them ruin the bolt, but if it does just grind the heads off and the rest of the bolt will come right out with no effort. They have big heads and enough surface area to cause the friction that keeps them tight. Since the bolts aren’t bottomed out, the threaded section will no longer have any tension on the threads.

 

OK, that's what I was looking for. Thanks. But I think the hell will have to be given with the engine out, most likely. Not enough room on jacks to apply the leverage, particularly without danger of damaging something else nearby if something gives suddenly.

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If you already have the trans out, you aren’t far from having the motor out so if it comes down to that it’s really not a big deal. My local Subaru dealer stocked the bolts and they were cheap.

 

If you wouldn’t mind, could you pm me the specs on your 6sp swap stuff? I am interested in doing the same on my 05 obxt

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If you already have the trans out, you aren’t far from having the motor out so if it comes down to that it’s really not a big deal. My local Subaru dealer stocked the bolts and they were cheap.

 

If you wouldn’t mind, could you pm me the specs on your 6sp swap stuff? I am interested in doing the same on my 05 obxt

 

PM'ed.

 

I have two more sets of flywheel bolts, clutches and flywheels - one new, one used.

 

It looks like it's mainly the messy stuff that remains to be done to pull the engine - disconnecting hoses with fluids in them, draining, etc. What I call "car juice" when I take it to the local hazardous waste disposal site. It looks like I just need to block out some time and get on with it.

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My DMFW was replaced with the Spec LWFW by the dealership back in 2007. In April 2012 I used my 1/2" impact gun to remove the bolts. I have the 30 gallon red Craftsman air compressor.

 

FWIW, I have seen the air impact out perform the electric guns.

 

DSCN4724.thumb.JPG.1e1a6ee9cee62422aaa84a354cf6e806.JPG

 

DSCN4726.thumb.JPG.4fcb293c6bac948acb696ead767c6b3f.JPG

305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD).  CHECK your oil, these cars use it.

 

Engine Build - Click Here

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Hey, FWIW, invest in air tools and a decent compressor. Harbor Fright has a good selection.

 

The other day I used my 3/8" butterfly impact gun, ($21.00) for a discount store like Lot's & More or Big Lot's, Ocean State Job Lot to loosen a 5/32" set screw in my 50 y/o Ariens snow blower. I sprayed the screw with Aero-Kroil, a few minutes later, took the butterfly impact, turned the speed down and tried it. I was amazed when it backed out the set screw with little effort. I tried a 5/32" Allen wrench and it would not move.

 

I was impressed with the air impact tool.

 

I do have Dwelt 12V impact driver, didn't even think of using that.

But I did use the 12V impact to remove the window handle from my 1986 F150 the other day when I broke the drivers door handle. That screw was a small torx. The handle was held on with a 5/16" hex head bolt. Used the 12V for that too.

305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD).  CHECK your oil, these cars use it.

 

Engine Build - Click Here

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305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD).  CHECK your oil, these cars use it.

 

Engine Build - Click Here

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less extensions helps. tightly fitting connections helps. I bought a speciality bit from a tool truck - impact rated 1/2" torx plus T50. Took all the slop out of system and used a pro-level 1/2" battery impact to turn it. Once I got one, i tried it with a 1/2" breaker bar with a 4' extension. Still had to smack the bar with a hammer to break it loose.

 

having a firmly attached engine is crucial if using the breaker bar. Handholding it on the bench was comical at best.

 

Also its a torx plus t50, not just t50. In case you have a different one.

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Most auto parts stores will have a T50+ bit. Worth it to make sure you have the correct Torx.

 

I have several. Most won't fit in the bolt heads. T45+ rattles a little bit, as does T50. Not sure what is going on there, but I've had someone else check and he agrees. And no, not just JimBob from across the way, either. I work in aviation and am surrounded by experienced aviation techs, most of whom do their own car work, too.

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You need a Torx T50+ for the OEM FW bolts.

 

I can get a picture of the package and bit if you want. I just rearranged the shed and know exactly where it is.

 

This is the exact one I have, I just walked out and checked.

 

https://www.amazon.com/OTC-TORX-PLUS-Socket-Square/dp/B000O846UI/ref=pd_lpo_263_t_0/147-7383569-0357311?_encoding=UTF8&pd_rd_i=B000O846UI&pd_rd_r=4d6353d2-e0b1-43b9-9e39-c8620ce8201b&pd_rd_w=bIMfj&pd_rd_wg=29SVM&pf_rd_p=7b36d496-f366-4631-94d3-61b87b52511b&pf_rd_r=TPHZMBH9X6ZFSJ8MV11D&psc=1&refRID=TPHZMBH9X6ZFSJ8MV11D

Edited by Max Capacity

305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD).  CHECK your oil, these cars use it.

 

Engine Build - Click Here

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You need a Torx T50+ for the OEM FW bolts.

 

I can get a picture of the package and bit if you want. I just rearranged the shed and know exactly where it is.

 

This is the exact one I have, I just walked out and checked.

 

https://www.amazon.com/OTC-TORX-PLUS-Socket-Square/dp/B000O846UI/ref=pd_lpo_263_t_0/147-7383569-0357311?_encoding=UTF8&pd_rd_i=B000O846UI&pd_rd_r=4d6353d2-e0b1-43b9-9e39-c8620ce8201b&pd_rd_w=bIMfj&pd_rd_wg=29SVM&pf_rd_p=7b36d496-f366-4631-94d3-61b87b52511b&pf_rd_r=TPHZMBH9X6ZFSJ8MV11D&psc=1&refRID=TPHZMBH9X6ZFSJ8MV11D

 

I have that exact one. The Amazon page the link takes me to tells me "You last purchased this item on September 5, 2020". It's not seating in the bolt heads, nor are the others. I bought about 3 other TP50s and two Torx Plus sets that include TP50 (or IP50 or whatever else it's called). One bolt head, the one I've worked on most, is getting a little chewed up, but the others are crisp.

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