Cap screws are weaker in shear than they are in tension. The general rule is that the allowable shear stress is less than 1.0/sqrt(3), roughly 0.57, times the tensile stress.
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Speaking of, how does one torque the four flange bolts? I’ve read they should be anywhere from 54-80 ftlbs?
Are you talking about the 4 bolts on pinion flange? If they are Grade 8 and 3/8" course thread, the applied torque would only be about 35 ft-lbs. 5/16" fine thread should be around 20 ft-lbs. Lower if not Grade 8. I doubt you will need a cheater to do that.
Also, in the example I gave above, I stated that 70,000 psi was roughly the allowable tensile stress for a Grade 5 bolt. That is not correct. It is roughly the allowable shear stress in a grade 5 bolt. The allowable tensile stress would be 1.57 (sqrt(3)) times higher, about 121,000 psi.
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Yes, those four bolts/nuts. They are Grade5 9/16" fine thread. I’m re-using the original bolts as they look fine. I’ve bought new self-locking nylon nuts, they are actually Grade8. I’m also going to put blue thread locker on the bolts.
Checked ROM (sorry). 27-32 ftlbs.
(Edited to correct the error in the fastener sizes pointed out by @Kirbert )
I’m gonna have to call you out on that. 9/16" is an extremely odd size for a cap screw. I have a stack of 2HA, 4HA, Dana 44 pinion yokes and companion flanges and none of them are close to 9/16". Truck Dana 44 yokes of the period used 5/16" u-bolts or 5/16" bolts and straps. I have a stack of Salisbury companion flanges and they all use 3/8" bolts.
There is no rational reason to use a chemical thread locker and a nyloc nut. Save it for where it will do some good, like the ring gear bolts.
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Yeah, 9/16" doesn’t sound right – but neither does 1/4"!!!
A big a’d C clamp… Good enough. I’d buy one. C clamps come in handy. I’ve a bunch under my bash bench .
Carl
Mea culpa, I stand corrected! That because you are correct! I turned 68 on Wednesday. My eyes have not been the same since! I actually measured the two Dana yokes on the left in the photo above. Both are 5/16", not 1/4" fasteners. The one on the left came from a 1950’s Ford F100 truck. The XK Salisbury flanges have 3/8" bolts.
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Sorry, what i meant was, the head of the bolt and nuts takes 9/16" socket. Dont know size of threads, but 3/8" sounds right. And im talking about four bolts that connect both flanges together.
The original nuts looked like nylocks, so i bought new ones.
Blue thread locker can’t hurt. Just may need a little more muscle to remove next time.
Got everything back in. All straightforward, except those two damn upper bolts that hold the crossmember in! Gotta be a hand contortionist! I also noticed, the crossmember has some wiggle room. Pushed back as far as i could and centered, to help clear transmission post mount. Very little clearance with crossmember, and the post can move up and down with transmission.
No test drive yet, still have to hook back exhaust pipes.
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I always thought the strap U bolts were a stroke of genius on driveshafts: makes it easy to remove the shaft, certainly works just fine in the street applications, and it’s simple.
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Shit…Im 64: THAT’S what I have to look forward to??
I’ll try to break this gently. I left out the impending hip replacement.
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Oh, that’s just great: I have a good rehearsal with the band, then I come home and read your post…
Mike S. is not alone with the impending replacement. You’re doomed, I tell you- doomed!
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Yeaaaa…pretty much coming clear, on the ol’–and I emphasize OLD–radar scope.
Nah your not doomed Wiggs, I’m 72 hips still work fine but do need glasses. Its all in your mind 
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Now, I’m in deep doo doo…!
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Backed her up in driveway, and then back into garage. Baby test. Worked fine.
Oh, and no exhaust. If the neighbors weren’t awake at 9:30am Sunday, they are now!
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Got new exhaust in, so took a few test drives today. The car didn’t explode, so i guess i got it right?
No vibration on acceleration, although got up to only 60 mph. I noticed any clunking going into D or R is gone.
Anything to check? I keep checking to make sure clips didn’t fall out.
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