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threaded rod for crank hub

2K views 22 replies 7 participants last post by  schlicky13 
#1 ·
Does anyone have a source for the grade B7 7/16"-20 threaded rod needed for removing/installing the crank hub? I started looking in local hardware stores this week and I can't even find fine thread rod, let alone something like B7. I checked my local fastenal suppliers online and no one within 100 miles had any on hand, and they only came in a two pack so I'd be looking at about $40. Amazon and ebay were similar. I was about to throw the towel in and just get the old kent moore tool kit, but those have gone way up in price if you can find them. The one complete set on ebay right now is $300, and there was an incomplete set (though I can't really tell what's missing) for $160.
 
#3 ·
I bought some at ACE - only because the other home stores didn't have the small size I needed. I just needed GR 5, but worth a call around though depending on what that B7 spec is.
 
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#7 ·
B7 is pretty close to heat treated 4140, so it's beefy. I used to machine a fair amount of pre-hard 4140 which is tough by itself, but once it's been heat treated to the final desired hardness, it's a bit of a pain in the butt to work with. I used to do a bunch of cnc work for dad and he'd always have me leave it .0005-.001" over spec just in case it warped during heat treating, because he or I could easily take it to what he needed on a surface grinder. But one time (I made precision robotic welding fixtures mostly) the parts being welded were so out of whack at the tool tryout (they were stamped in china, never a surprise when they weren't to spec) that a bunch of finished locating pins that were usually hardened up to around 58-60 rockwell with diamond shaped locating doo-da's machined into the end had to be re-machined to take, something like .050" or more off the overall height with a matching amount of depth added to the diamond shape. Took all afternoon and I burned up about a dozen carbide end mills, but I got all the pins reworked in time to finish the tryout and send it out with the people that came to pick it up. Anyways, I opted for the zinc plated rod, I figure that will add some rust prevention when I'm not using it and should slick up the threads some too, hopefully making it a little easier to get the job done.
 
#5 ·
When I did it on the Caddy I rigged something up with the crank hub bolt not realizing it was a dumb idea. It worked, but I did booger up the first few threads by the time I was done. Between a thread file and a tap and die set I had it all back to like new condition (and I've also since gotten an ARP bolt to install on the Caddy) but I don't intend to use that method again when I pull the one on the truck. Longest bolts I've found anywhere were 2", but I didn't look up what fastenal suppliers had locally.
 
#6 ·
I ended up ordering from grainger. Their nearest location is just over an hour away, but shipping was $11 so for $15 it's a done deal. They didn't have anything shorter than 3ft for what I was looking for, but worst case I can cut up a bunch of 6" pieces and sell the extra pieces on here. I wanted the harder grade because it'll get used more than once. I popped the hood on the Caddy the other day now that everything is thawed and melted around here so I could top off the battery and then fire it up and much to my dismay the Torqhead crank hub is a rusty, rusty b-otch. That's only been on just over a year and it is by far the rustiest thing on the car (because there's mostly no rust anywhere on it). I can only assume that he's spray painting the hubs because it's flaking and peeling and revealing massive rust underneath and it's starting to spread to the damper. Not impressed to say the least. Not sure what I'll do about it, but at the very least it'll need to come off for a better coating of some sort. So basically I just wanted a tool I can use over and over without having to worry about.
 
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#10 · (Edited)
There you go. I noticed the bolts on the balancer are starting to get a little surface rust too, but I already know ARP makes stainless hardware for those and I'd already been thinking about ordering a set. The hub though, that really annoys me. It looks like most of the flaky stuff blew off after I started it up and ran it for awhile the other day.
 

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#11 ·
There you go. I noticed the bolts on the balancer are starting to get a little surface rust too, but I already know ARP makes stainless hardware for those and I'd already been thinking about ordering a set.
The hub though, that really annoys me. It looks like most of the flaky stuff blew off after I started it up and ran it for awhile the other day.
Dreamt of the TorqHead kit, plus a torquey cam with a 1-8-7-2-6-5-4-3 firing order, and running it with an Aussie operating system for … better economy.

This makes me hesitant.
 
#12 ·
I need to get in touch with the guy at some point soon anyways. I think he assumes I gave up trying to get a d-body specific version of the kit after I popped a head gasket and had to put the car into extended storage. It isn't strictly compatible with the Fleetwood as I found out after installing, traction system is non-functional (which I may end up deleting anyways, but it should be integrated for those who want to keep it and he did get the Corvette version of it working so...?) and there's a weird glitch on the dashboard, the speedometer climbs when revving the motor, even when in park and standing still. And I also noticed the other day when I fired it up that the odometer is also climbing because I happened to notice the trip odometer pick up a tenth while it was running. I haven't got the faintest idea why that is, and he was going to look into it but then he got into those smaller sized alternators so we could run any off the shelf valve covers and I haven't heard from him in forever. And I think there was at least one other little thing I noticed that wasn't working right, but I forget, I'll have to go back through the emails. Anyways, once I reach out to him again I'll see what he says about the hub rusting like that.
 
#19 ·
B7 is available from McMaster-Carr. 1 foot length is $7.33. I have been buying from them for several years. Great service.
Already ordered from Fastenal, but a 1ft length would have been more convenient than the 3ft I had to order, however it was only $4 + $11 shipping, so for $15 I'm ok with it.



I am pretty sure I have 2.5' of the stuff in my garage. Happy to cut off a section and send it to you if I do.

Already ordered a 3ft piece from Fastenal by the time you replied, however I do appreciate the offer.
 
#18 ·
Up until recently Home Depot was advertising Crown Screw & Bolt company's 7/16-20 socket head cap screws for like $5 apiece; I tried ordering two and weeks later they said they were out of stock and cancelled my order. Darn. Dan, sent you a PM.
 
#23 · (Edited)
Yeah that page I linked did show pretty good pictures of the two styles of cranks, so I at least understand the physical differences. I'm less certain how they differ functionally other than what I read. I'd be curious about one of those intakes though, still weighing my options in that regard. I know our stockers aren't horrible, but they do leave room for improvement. If nothing else I plan to send one in to Lloyd Elliot for porting. I also have a Lingenfelter/Accel SuperRam I had originally intended to use but since I've decided to switch to boost and the fact that those intakes are notorious for not sealing properly, I'm thinking it'll either sit on a shelf or go up for sale. If I had access to my dad's machine shop I could easily remedy the sealing issues, but that's not presently an option. On the other hand, since I'm going to be running boost intake design becomes less of a concern since the air will get there one way or another. Although I'm sure there's still always room for improvement, it just becomes a question of whether or not it's going to give enough extra hp/tq to justify the cost.


I think I actually found the car on their website, it was a Caprice belonging to someone named Greg. And they're not that far away. I might reach out to them and see what they think about running one of their manifolds with a procharger feeding the air.
 
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