Check your BTB bolts!

[inanecathode]

Even if they're new, check the torque on your brake tensioner bar bolts. Even though it was my fault mine broke, i could see how easily even a tiny bit loose BTB bolt could sheer off!

[h2olawyer]

Read the warning post at the top of this section of the forum.   ;D

H₂O

[inanecathode]

Yeah yeah...

[jasonm.]

Some are replacing with 8mm bolts. This is WRONG. The brake bar and associated parts holes and shoulder bolt are 10mm!  Use a 10mm and grind the head to fit it at the drum!  Yamaha did not need a 10mm nut if these are properly installed. The 8mm supplies the sufficient torque. But the hardware store fix I have stated works great.

[Evan]

Just getting back to working on my V, and saw the warning about the BTB bolts (mine look fine, no corrosion), so I went into the local dealer.
90109-08368-00 $3.11
90109-08406-00 - not available anymore, but he pointed me to
http://216.168.60.165/speedandsportinc/index.tpl
which does have 22 in stock, for $3.32.

I tried looking at HW stores for something close, and would just rather order one that is correct (if it is available).

[Aelwulf]

Bit of thread necrosis, but the one up top's locked. :p

I got new bolts and all at Fastenal for KJ's '83 (for free at that).  Her bolts and bar were pretty well rust-coated.  I cleaned up the bar with my Dremel and some PB.  I got bolts that were the same width the entire length as the shoulder was on the original bolts, which I believe is the proper size.  I replaced the regular washers and lock washers and replaced the nuts with slightly larger (due to the new end diameter) locknuts (think teflon ones).

Now, assuming all that is good and all, I have one question: with having both a lock washer and a locknut on there is the cotter pin necessary?  I was going to put 'em on anyway after drilling holes just for piece of mind but the only drill bit I have that'd work wouldn't do more than make a dent in the new bolt (good for the bolt, bad for hole-making :p).  Considering I've done locknuts only on some F-16 parts I'm not particularly concerned about it, but thought I'd check with those who'd know better just to be sure. :) Thanks.

[Walt_M.]

Considering the possible consequences of a failure, I go with a cotter pin or drill the nut for safety wire. Though I don't like the drilled out tensioner bar. If it was that simple, I don't think Yamaha would have gone to the extra expense of the shoulder bolt.

[Tiger]

 :) Like Aelwulf, I use the same/similar fix regarding these bolt's. However, i don't use a lock washer and Nyloc lock nut, just the Nyloc and a flat washer...and I don't have mine drilled for wire/cotter/hair pin's.

During any maintenace, any hardware that I remove, nuts/bolts/washers/cotter pin's, etc are dispatched into the recycleing box!!! and new hardware installed... :o

Given that I sell, among other things, hardware for a living to a variety of industrial maintenance people, it does help!!!

            8).......TIGER....... 8)

[Aelwulf]

Yeah, I've got a regular flat under the lock washer similar to the ones that came off.  Locknuts like the ones I put on I replace every time I take 'em off, lock washers depends on the condition of the washers, cotter pins every time.

What sort of drill bit should I look for to retry drilling for the cotter pins?  Not sure exactly what the one the Fastenal gave me (small one same as in their full 'professional' bit kit, tossed it in with the bolts) but it's gold with grey on the inner grooves.  I'd like a good strong set from Sears or such but can't swing the cash for one yet.

[Lucky]

there are a few key points to make drilling into metal a whole lot easier:

1) invest in a drill bit sharpener. it doesn't have to be expensive, it's just a grinding stone. the trick is that it grinds the bit at the proper angle.  i used to work with a guy when i lived in S Florida, Jack Bargeone, who could sharpen drill bits by hand. it allways amazed me & i could never get the knack of it. we also learned to scuba dive together. i drew the line at his next suggestion, skydiving...
I easily spent more than the sharpener cost on replacement bits every year, & i had a draw full of them! (now i have a draw full of sharp ones)

2) now that your bit is sharp, center punch the metal so the bit doesn't wander as you start off.

3) apply cutting oil to the tip of the bit, really any oil will work: motor oil, WD-40, machine oil, etc, as long as it's oil.

4) drill at a medium to slow rate. speed overheats the tip & dulls the bit instantly. you want to drill at a rate that gives you either long curlys or chips of metal. softer metals give longer curlys, harder metals give you chips.  this take a little bit of experience.


hth, --Lucky

[Lucky]

oh, 2 more things, aircraft quality bits aren't nessacarily better. most aircraft are made from aluminum. ('aircraft' bits were intended to drill holes in the aluminum body for rivets.)  hard steel bits are fine for most uses, & will resharpen 'till they are very short. cobalt bits are nice, good for the occasional hard metal, but are harder to sharpen.

if you can find them (or order from Northern tool) get yourself a set of reverse drill bits ('left handed') there is no better way to remove a broken bolt or stud!!!!! (these you have to sharpen by hand  :-\  )

--L

[Rick G]

Lucky . I'm the other way , I've tried drill sharpeners, but I can do better by eye. Been doing it a while , there were no sharpeners when I started.
I do what you said , but I also  grind a small flat spot ,so its easier  to put the dimple with the punch.

[Lucky]

whatever works eh?  :D :D

i'll grind a flat spot too sometimes

[Aelwulf]

Yeah I did the punch part, and had flakes coming off some but it got to a spot It hink just below the depth of the threads and wouldn't go any further.  I'll look into the gear.  With double locks I'm not worried about it popping off anytime soon so I've time to find equipment.  Thanks. :)

[inanecathode]

Man i still remember that bolt breaking. Puckering moment for sure lemme tell ya.