The Stovebolt Site Forums The Parking Lot '60-'66 Trucks Bellcrank / Area 51

Has anyone ever drilled a hole in one of the arms of a clutch bellcrank? We recently tried. You know that scene from the movies: Air Force Base, deep in the desert, high security, big hanger, captured alien craft, boffins attempt to drill into it...... Well, I'm thinking GM bought some 'used' metal from Roswell back in the 50s and made a few bellcranks form it. This thing's nuts. Fancy yourself a workshop whiz? Find yourself an old truck bellcrank and be prepared to be utterly humiliated. Guaranteed.

Must be "Harder Than Hammered Owl $hit, eh?

Here's a couple ideas:

Try a flame wrench, clean up the hole with a die grinder.

Or if you have a welder, crank up the amps and burn a hole through it with an electrode, then clean up the hole with a die grinder.

are you trying to compensate for a worn out clutch or worn out linkage. remedy; new clutch assy or repair the linkage. thinki8ng about it if you are drilling a hole in the zbar means that you are shortening the stroke which will give you less throw.
the trick to drilling harder steels is start out with a sharp bit and drill speed - slow.use a smaller bit to drill the pilot hole.
ron

Get rid of the Chinese drill bits and get U.K. or U.S.A. As Pad says: start out small and work your way up. That's how I got my start.

Dudes, no ,seriously, best drill bits money can buy will not so much as leave a tickle mark, I promise you. You should try and see for your self. As to the motives for this particular caper, I've got to modify the whole linkage, convert it to push clutch fork forward instead of backward per original. It boils down to me having to reverse the arm beside the steering column to make the rod push down instead of pulling up. Make a hole in the floor about 3 or 4 inches below original hole, then extend the arm of the bellcank by about 4 or 5 inches so the clutch rod drops straight down onto it. So I get me some 25x5mm stainless - which I'm warned is as hard as hell and hard as hell to drill through. My money no object bits go right through with dazzling ease. I use the existing hole on the arm of the bellcrank as the first fastening point then figure I'll make another for my second. Bellcrank hasn't read the script. My son arrives, a partner in a speedshop, thinks he's seen it all, thinks his oldman's a schmuck, says he'll do the dishes for a week if he doesn't make a hole. Gets out his Snap-On pilot punch from its jewel encrusted Snap-On box, his confidence could tan me and I hate him and love him at the same time. I sincerely believe he can do this. Bellcrank disagrees. Snap-On pilot punch's deadly sharp tip looks like the end of a pool cue. My son looks like five, outside school, no one there to collect him, says I misheard the dishes thing, we argue, he searches in vain for a mark on the bellcrank, there's nothing doin, we argue, he takes it over to his shop, pillar drill, weapons-grade speed, weapons-grade bit, bellcranks kicks [censored], we argue.

Forget the Hellcrank, if you and he have all those resources.........MAKE ONE!..... Does not have to be super strong , just strong. 1/4-3/8 thick carbon steel or you have that 1" x 1/4" Stainless piece, right? Plasma, bend, weld, drill, fabricate mate, make peace in the family. Father and son project, aye? "Man the women, full speed ahead!"

usually a very slow speed will do it. if you have started already at higher speed it doesn't go anywhere and seems to harden the steel all the more.
so what have you done to it that you have to reverse the travel of the throw out arm. please enlighten.
ron

Well; that is what a bell crank does, change direction of rod motion. Are you sure you can't use it somehow? repositioned. I'm curious also but it would take some pictures for me to understand why you need such major changes. I assume clutch fork ended up too far back or forward due to some swap. Seems like push fork forward with push forward pedal is no bell crank at all.

The parts are case-hardened, so they will not drill easily. Sounds like your are modifying the truck around the z-bar. Why not find the correct z-bar for your truck?

I'm in this too deep now, it's me or bellcrank. And I know all you folk mean well what with all the advice and such but that son of a ''' will be going back in it's place and do its thang come what may. Right now it sits atop the counter in my Son's shop, sneering, displayed as the meanest piece of ..... while I readjust my strategy.
As to why this has happened starts with the fact I live in the UK. Makes for restrictive choice, makes stuff harder and more expensive to come by. It's also safe to say we know a bit more about Tremec transmissions now than we did a few years back. Some three or four years ago I bought a TKO500 from our local Tremec dealer to sit behind my truck's SBC. Got trade price too. It was a complete kit (clutch, bellhousing etc etc) However, it was and is a Ford TKO. Why? Hell knows, I'm guessing Fords were cheaper, import duties, something. Whatever. Anyway, it's a tried and tested set-up here in the UK to work bolted up against chevys and it does all go together pretty cute, apart from, of course, having to move shifter to mid point - thank you Son. Though its fair to say that goes for either. Yet let me just say here and now: Tremec's claim of countless shifter positions is, what shall we say, FLAWED. Example: the adapter to position shifter at most forward point (Tremec only item) and perfect for bringing shifter right up and out of the original hole, is not shy of cost of whole trans!!! Be warned.
So, I now have a clutch-fork which must be pushed forward. Great. But I have a linkage designed to push clutch-fork backward. Great. Someone it the shop suggested converting to cable. That wasn't going to work, It was all over the place. I sat and stared for a long time at what was already there. Figured to simply reverse the points of leverage. It should and could actually work. Need only now to get a neat hole put in something.

you can always go to a hydraulic clutch mechanism and may save you some grief. I can get the info for the mounting of the clutch master. it is used for the 60-62 model when guys upgrade their brake systems
http://www.67-72chevytrucks.com/vboard/showthread.php?t=362375
ron

Anything's a possible option, though for now I'll keep going for a hole in that SOB. Still really like to know what it's made of, it's not magnetic that's for sure and we've never encountered stainless like this. Impenetratium....from........ Roswell? Have to sign off now there's an Econoline at the curb, big aerials, two dudes at my door, dark shades, coveralls, say come to fix my cable. AHhhhhhh, I have no cable.............

You are in the UK? Well, that explains it! I wish I had seen that sooner... your drill is running backwards.


Just kidding of course.

its been done before, I think. Can't someone send you what you need as a gift, by postal, and you pay no taxes? Just trying to help you out before you take the torch to it ....

Do you glow in the dark now that you have touched it, tried to drill it? Some saucer is missing it's ramp hinge.

If all comes to naught take it to a machine shop who has EDM.

I think a cobalt or carbide tool should be able to cut thru hardface.

Slow drills drill best and last longer.

Dan Bentler

Dan, I think you're on the money. Seems while sitting on the counter top, a dude by name of Justin came in the shop. Son says Justin is their lathe service engineer and really knows his metals. This Justin dude took the bellcrank saying he'd get the mother 'sparked'. Next day the bellcrank appeared on the counter. Perfect hole.
Son called to ask how and say thanks. Justin says it was a lot harder than usual, says bit difficult to talk, has couple of fellas in to test the gas..... he pauses, says he's not on gas.....
Any how, big thanks to the man - wherever he is, and I'll get it all bolted up and post some pics.
Not saying it'll work!

In my bin of factory bell-cranks, they all have a threaded grade fitting. Must have been tough drill & tap, to penetrate the impenetrable.