Flywheel Bolts

[zokustyle 0]

So I've got a used OS Giken clutch that came with flywheel bolts. They're shorter, because of the thinner flywheel. The regular bolts (GE, 4AG ARP, etc.) have an UHL of 1.050in. These OSG bolts have an UHL of 0.875in. They look to have identical shank/grip length, just shorter threads on the OSG bolts.

 

Here's my questions:

Are OSG bolts even re-usable? If they are, then we can shut this thread down and I can get on with life.

If they aren't and I go with the standard JZ bolt with UHL 1.050, will that 0.2" be too much and I should just bite the bullet and buy some 2ZZ bolts?

 

Here's a picture of the standard bolts, OSG, and flexplate from L>R:

[Gordo 0]

Use the longest ones that will fit, even if it means bottom tapping the holes in the crank.

Those short ones scare the bageepers out of me........

[Gizmo 0]

Woooooord^... Last thing you want is that.flywheel coming loose. I've heard horror stories, bro.... Horror stories.

[zokustyle 0]

Yeah I like my legs.

 

The problem isn't threads on the crank not being long enough, they go right on through. I just confirmed that the standard length bolts do go too far, they bottom out on the crank.

 

Soooo it's either shortened ARP's, taking a look at 2JZGTE bolts, or reusing the OSG bolts.

 

There's zero info on whether the OSG bolts are TTY.

[zokustyle 0]

Also, the OSG's are shorter because the OS flywheel is just 1cm thick, versus the thicker standard flywheel. They don't meet any less threads in the crank, they just have less too pass through than the standard bolts.

[Gordo 0]

I doubt that they are TTY.

But the thing is with used bolts, you have no idea if the person who had this before you was an idiot, andf had over torqued them.

 

By the way, I now spend a few bucks more, and have my ARPs cryo treated.

I have sheared them off before.

[Gizmo 0]

Just get new shortened ARP bolts, id rather be safe than legless lol Id say go OEM but that's out of the question considering your flywheel is thinner.

[Gordo 0]

Thinner, but cut from solid steel, not cast like an OEM flywheel.

I doubt if it would explode, but bolt failure will ruin your day none the less.

You will kill the crank, flywheel, and a good chance the trans input shaft if your at speed when they fail.

[Austin 0]

I had bolts come out of my flywheel once, torqued themto 30, for got the 90*, and drove on it for 3 days. When they backed out, thankfully none sheared, but it made a hell of a racket. Very scary stuff.

[zokustyle 0]

What's the story on factory Toyota bolts' willingness to take a beating?

 

I found that 2JZGE part# 90910-02103 supposedly has the magic 23mm length. Still looking to confirm that, toyodiy and village toyota only have application, diagram, and price, no measurements.

[Gizmo 0]

I've never heard anything bad about Toyotas bolts. People using the stock flywheel with the OEM bolts pushing 500+HP and everything still holds up smoothly.

[swim 0]

subtract the thickness of the OSG hub from the thickness of the stock FW hub, subtract the resulting number from the length of the stock bolts, find flywheel bolts in the ARP catalog that are that size, order.

or at least post the thickness of the stock FW, the thickness of the OSG flywheel

1.050" UHL = 26.67mm so we can start there I guess

also don't cut ARP's down if you don't have to. you'd fuck up that rolled thread goodness.

[Gordo 0]

I've have run tooling washers under ARPs as long as there is enough clearance between the clutch disk, and the heads of the bolts.

I also have brought in ARP studs, in case I had any more problems with snapping the heads off their bolts from the shock loading I was putting on the 7M crank.

Never used them, as when I doweled the crank, the problem went away.

Well, not quite, the problem migrated to the next weak link, the converter bolts.

Fucking Toyota, and their fucking 9mm bolts.......

So the converter was modified to take ARP 10mm bolts.

[zokustyle 0]

OEM flywheel is supposedly 12.5mm.

 

I'm pretty sure I'm just going to do the 2JZGE bolts. The OSG's are like, 22mm so I get an extra 1mm of threads with the 2J ones.

[zokustyle 0]

Looks like 2J-GE bolts are the ticket. They're like 1mm longer under the head than the OS bolts:

 

[Lofty 0]

Glad to see loctite red on them

 

 

[bippu 0]

If you still need the OS bolts let me know. I'm Canadian distributor for OS.