FNG Question about bolt taps and inserts

[Montreal]

Hey all.

New owner.

Questions.

I am working on a clutch lack of pressure (Dragging).

And I removed the clutch slave to clean and check for leaks.

Here are my findings.




The top bolt, the one centered in my pictures is odd.....
It was made by someone.



IT seems to be 7 mm treads instead of 6mm, it was ground to length and the head is a welded 11mm nut.
As far as I can shed light on the subject the treads in the hole looks fine.

Said nut barely fits in the recess. A socket doesn't fit. I had to use the very tips of a wrench to rotate the head.



So.

First. Apart from the red-neck bolt. Is this a "Normal" FJ thing?

Second it looks to me as if someone re-tapped the tread larger and made a larger bolt fit (At least he didn't go to an imperial size).

I know nothing about insert.

Did that someone re-tap and not put in an insert? I don't know how much of an oversized the tap as to be for a wanted bolt.

Can I put an insert in there and make it good? Ideally I would like a stainless-Allen head 6mm bolt in there.

I probably can find a fine tread 7mm bolt of the proper length on Ebaby but I resent paying $20 shipping on a $1 bolt.
My favourite bolt emporium didn't have that diameter (Their attitude was like: "That's a bolt from space, man!).

All comments appreciated.

Thanks.

[red]

Montreal,

I would replace that home-made bolt with an Allen-headed bolt or machine screw, and if the old bolt works, just match the new Allen screw threads to the old bolt.  No telling what threads were/are in that hole, but if it works, stick with the size that you have.

If you are in the USA, go to:

www.anywho.com (the real Internet USA Yellow Pages), click the tab to find a business, and add the heading

Nuts and Bolts

and Search.  These hits are not gonna be the common hardware stores.  They probably will have what you need.  Give Anywho a local ZIP code, and it will Sort the search results by distance from you.  Call ahead for stock, where that is possible.

Monteal (if you are there) probably has a similar resource there.

No charge, here . . .   
.

[racerrad8]

There is supposed to be two long bolts and the one short bolt. The two long bolts pass all the way though the chain guard into the case. You need to investigate what the issue is with the second, missing second long bolt.

Without that bolt securing the slave and chain guard, they could be flexing away from the case and causing your clutch drag.

In closing, the Yamaha slave bolts are in stock: http://rpmracingca.com/search.asp?pg=1&stext=slave+bolt&sprice=&stype=&scat=&sfil0=

Randy - RPM

[krusty]

I thought that too when looking at the three bolt lengths as I had a slave cylinder off a couple of weeks ago. I'd be looking deeper into where the odd bolt was. Is there a sheared off 6mm still in there? If so can it be extracted and correct length bolt replaced or if there's nothing in there go for a helicoil insert.

[woodcreekpete]

There is supposed to be two long bolts and the one short bolt. The two long bolts pass all the way though the chain guard into the case. You need to investigate what the issue is with the second, missing second long bolt.

Without that bolt securing the slave and chain guard, they could be flexing away from the case and causing your clutch drag.

In closing, the Yamaha slave bolts are in stock: http://rpmracingca.com/search.asp?pg=1&stext=slave+bolt&sprice=&stype=&scat=&sfil0=

Randy - RPM


7mm bolt is a pretty strange animal. If you have room and enough depth, helicoil it back down to 6mm. The bolt should be ths same length as the longer one. If you use stainless, make sure to use anti-seize on it - once a stainless bolt seizes in a hole, removal is a seriously difficult proposition. If you need an original bolt, I've got a couple.

[Montreal]

Montreal,

I would replace that home-made bolt with an Allen-headed bolt or machine screw, and if the old bolt works, just match the new Allen screw threads to the old bolt.  No telling what threads were/are in that hole, but if it works, stick with the size that you have.

If you are in the USA, go to:

www.anywho.com (the real Internet USA Yellow Pages), click the tab to find a business, and add the heading

Nuts and Bolts

and Search.  These hits are not gonna be the common hardware stores.  They probably will have what you need.  Give Anywho a local ZIP code, and it will Sort the search results by distance from you.  Call ahead for stock, where that is possible.

Monteal (if you are there) probably has a similar resource there.

No charge, here . . .   
.

Thanks.

It seems to be unobtanium. for now anyway. When I have more time I will try again.

[Montreal]

There is supposed to be two long bolts and the one short bolt. The two long bolts pass all the way though the chain guard into the case. You need to investigate what the issue is with the second, missing second long bolt.

Without that bolt securing the slave and chain guard, they could be flexing away from the case and causing your clutch drag.

In closing, the Yamaha slave bolts are in stock: http://rpmracingca.com/search.asp?pg=1&stext=slave+bolt&sprice=&stype=&scat=&sfil0=

Randy - RPM

I have to investigate the chain guard.

Thanks.

[Montreal]

I thought that too when looking at the three bolt lengths as I had a slave cylinder off a couple of weeks ago. I'd be looking deeper into where the odd bolt was. Is there a sheared off 6mm still in there? If so can it be extracted and correct length bolt replaced or if there's nothing in there go for a helicoil insert.

After reading your reply I probed the hole of the "7mm homemade bolt".
The bottom is way to close to insert an original long bolt.
The bottom also feels bumpy.

So...Yah...Briken bolt in there. The previous owner made himself a fix....

I would love to helicoil and normalize this but It will have to wait a bit longer.

Thanks.

[Montreal]

There is supposed to be two long bolts and the one short bolt. The two long bolts pass all the way though the chain guard into the case. You need to investigate what the issue is with the second, missing second long bolt.

Without that bolt securing the slave and chain guard, they could be flexing away from the case and causing your clutch drag.

In closing, the Yamaha slave bolts are in stock: http://rpmracingca.com/search.asp?pg=1&stext=slave+bolt&sprice=&stype=&scat=&sfil0=

Randy - RPM


7mm bolt is a pretty strange animal. If you have room and enough depth, helicoil it back down to 6mm. The bolt should be ths same length as the longer one. If you use stainless, make sure to use anti-seize on it - once a stainless bolt seizes in a hole, removal is a seriously difficult proposition. If you need an original bolt, I've got a couple.

All good suggestions.

As I replied earlier it looks like a broken bolt at the bottom of this hole.

Will have to wait.

Thanks.

[fj1289]

Get a nice sharp narrow punch and center punch the broken bolt.   Then use left twist drill bits to slowly and carefully start drilling out the center of the broken bolt.  As you get through the broken bolt, increase the drill size.  Between the heat from drilling it, possibly weakening the bolt, eventually one of the left turn drill bits "should" "snag" the broken bolt and back it out. 

[red]

Get a nice sharp narrow punch and center punch the broken bolt.   Then use left twist drill bits to slowly and carefully start drilling out the center of the broken bolt.  As you get through the broken bolt, increase the drill size.  Between the heat from drilling it, possibly weakening the bolt, eventually one of the left turn drill bits "should" "snag" the broken bolt and back it out.

Montreal,

That's a plan; they also make screw extractor sets that might work, after you get a hole started (1/4"" ~ 4mm) deep into the broken bolt.  Before you start, rest the bike on one side as far as is practical, with the bolt hole pointed upward, and put in as much penetrant-oil /rust-buster as the hole will hold.  Give the chemicals a day or three to do their thing, maybe adding more to the hole after a day.  Then go after the broken bolt as above.  I would not be in a hurry, there.  Chemicals will need some good time (not just minutes or hours) to work.

If you have a heat gun, you can try cleaning away all chemicals with tissue, then warming up the metal before using any serious force on the broken bolt.  Be careful where the heat goes, while you work; a heat gun can melt lead solder.  Protect any plastics nearby with wet towels, and change the towels for cold after every few minutes.

Best wishes.
.

[krusty]

When drilling out seized bolts it is very important to make sure that the drill goes in straight. Replace the housing using the two good bolts and use the hole over the bad bolt as a drilling guide. Use a drill bit that just fits the hole. Use good quality sharp drill bits. Drill in a short distance to get the hole centred then change the bit to one that suits whatever extracting device you intend to use.
Using this method (sans extractor) I have been able to drill out a bolt just leaving the bolt thread left in the hole thread and been able to unwind what is left leaving the hole thread intact. Doing it this way involves care and precision but can get a good result.

[krusty]

When drilling out seized bolts it is very important to make sure that the drill goes in straight. Replace the housing using the two good bolts and use the hole over the bad bolt as a drilling guide. Use a drill bit that just fits the hole. Use good quality sharp drill bits. Drill in a short distance to get the hole centred then change the bit to one that suits whatever extracting device you intend to use.
Using this method (sans extractor) I have been able to drill out a bolt just leaving the bolt thread left in the hole thread and been able to unwind what is left leaving the hole thread intact. Doing it this way involves care and precision but can get a good result.

I forgot to mention. Avoid using extractors such as Ezi outs. I have never been able to use one successfully, they always seem to break and that leaves you in a worse position. As others have mentioned, go for reverse twist drills.

[fj1289]

Rusty - I was just going to add the same thing!!!   

http://www.fjowners.com/index.php?topic=19343.msg198263#msg198263

A link to an alternative

[ELIMINATOR]

Just in case you don't know!

Assuming that it is a standard M6 x 1 pitch, the tapping drill is Ø5.

The rule for  metric tapping drills: Whatever the thread size, the tapping drill is the thread O/D minus the thread pitch