strotter Posted October 7, 2002 Share Posted October 7, 2002 Where did y'all find the bolts to fasten the JTR universal joint to the Datsun diff? I have a some from the hardware store that are good enough for moving my Z around the yard, but it needs some good grade 8+ for the permanent setup. I can't find any anywhere. Perhaps on the 'net somewhere? Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted October 8, 2002 Share Posted October 8, 2002 You should have a few "fastener" stores in Lodi that sell nuts and bolts exclusively.. You want fine thread "grade 8" 1/4 inch diameter allen head bolts about 1 1/8 inch long with plastic fiber lock nuts I just took my Neapco N2-2-899-1 adapter into the Fastner store and fiited with fasteners. Quote Link to comment Share on other sites More sharing options...
jt1 Posted October 9, 2002 Share Posted October 9, 2002 Grade 8 bolts are the way to go, with self locking nuts. On my car I got some longer ones and cut them off to lenght. This allows the unthreaded shank at the top of the bolt to go almost all the way thru the two flanges for more strenght. If the threaded portion is at the shear plane between the flanges, it's not as strong as the unthreaded shank. I cut the longer bolts to lenght, then used a die to thread the shank to just inside the flange so the nuts would tighten all the way up. IMO this is stronger than using the shorter bolts. If you can't find the grade 8's at an auto parts, try a heavy truck or tractor repair shop, or an industrial supply house. Hope this helps. John Quote Link to comment Share on other sites More sharing options...
Dragonfly Posted October 9, 2002 Share Posted October 9, 2002 Jt1 I am not saying what you did with your drive shaft bolts is incorrect but I want to tell you what I was just reading last night. I am reading the book "Engineer to win" by Carrol Smith and in the chapter on bolts he says that the weakest part of a bolt is where the threads end at the shank and if the bolt is being used to fasten parts the shank should be shorter than the thickness of the part it is inserted through, this allows the bolt to exert its maximum clamping force. If the bolt is being used in a double shear application (which the drive shaft flange is) he says to make sure the shank goes all the way through then you add a hardened washer to torque the nut down to. The other important thing he said was not to cut threads into the shank of a bolt as a die will tear the metal and create numerous stress risers that you can not see with the naked eye which greatly reduce the life expactancy of the bolt. The reason I am going on about this is because it will not break untill you need it most ie that race you just bet your mortgage payment on or that semi you pulled out in front of so as not to be stuck behind him blah blah blah. Dragonfly Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted October 9, 2002 Share Posted October 9, 2002 Dragonfly ...good point! I got my Neapco diff adapter out and sure enough I bought fully threaded grade 8 bolts.If they get loose, there is a good possibility of shearing.Your correct about having no threads inside the bolt holes only unthreaded shoulders. Buck knives used to have a logo of a Buck knife cutting thru a bolt which was impressive until you understood that about any sharp object could shear a bolt if the sharp edge was placed between the threads and pounded on with a blunt instrument.Threading weakens the steel which is why fine threads are a lot stronger than coarse threads. Quote Link to comment Share on other sites More sharing options...
pparaska Posted October 12, 2002 Share Posted October 12, 2002 Good point about the threaded part being in the hole. On some bolts though, the shank is a bit bigger than the outer diameter of the threaded part, so it may not be a problem. I used Aircraft Shear bolts - NAS bolts. Yeah, expensive at $3+ a piece, but big deal. They are MADE for shear loading and are stronger than grade 8 and AN bolts in shear. I got mine at Aircraft Spruce and Specialty, but McMaster Carr or any aircraft hardware supplier can get them. I used milspec nylock nuts AND red loctite. Quote Link to comment Share on other sites More sharing options...
jt1 Posted October 13, 2002 Share Posted October 13, 2002 You know, it didn't suprised me a bit that Pete used some aircraft grade:titanium:scandium:unobtainium bolts in his drive shaft. I just wish I had thought of it. I agree a bolt with an unthreaded shank just long enough to pass thru the two flanges, with a hardened washer, would be an ideal solution. I was faced with the choice of fully threaded 1" bolts or 1 1/2" bolts with an approx 5/8" unthreaded shank, too long for the nut to tighten. So I threaded the shank enough for the nuts to tighten. I also agree rolled threads produce less stress raisers than cut threads. Until we locate the perfect bolt for this (maybe Pete has) I would rather have an unthreaded portion between the flanges, even with some cut threads, than a fully threaded bolt. If a shear failure occurs, it's going to be along the plane between the two flanges. The unthreaded shank will provide more shear strenght than the threaded part. This is a single shear application, not double, but I don't think it makes any difference. If anybody finds that perfect bolt, please let me know. I'd like to have a couple of sets. John Quote Link to comment Share on other sites More sharing options...
TimZ Posted October 13, 2002 Share Posted October 13, 2002 Originally posted by pparaska:I used Aircraft Shear bolts - NAS bolts. Yeah, expensive at $3+ a piece, but big deal. They are MADE for shear loading and are stronger than grade 8 and AN bolts in shear. I got mine at Aircraft Spruce and Specialty, but McMaster Carr or any aircraft hardware supplier can get them. I used milspec nylock nuts AND red loctite. This is the way to go for driveshaft bolts. (Pete never half-asses anything ) Grade 8 bolts are designed for strength in tension, and as I recall, aren't the best thing to use for shear. Actually, I seem to recall Grade 5 being stronger in shear than Grade 8, but I'd have to confirm that. If you don't like the idea of the Mil Spec pieces, why not just call Courtesy Nissan, and get the actual driveshaft bolts, nuts and washers? They are shear-type bolts, and are designed for the application. BTW, the bolts in the driveshaft flange are in single shear, not double shear. Single shear is more stressful on the fastener. Quote Link to comment Share on other sites More sharing options...
jaime240z Posted October 16, 2002 Share Posted October 16, 2002 A little off the subject. I asked this in a different topic before I stumbled across this thread. You guys using the JTR adapter flange: Did anyone have trouble finding an R-200 that would bolt up to the adapter? I seen to be having trouble trying to find a 3.54 R-200 with the same dimensions as my adapter flange? Any advice? Thanks! Jaime Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted October 16, 2002 Share Posted October 16, 2002 Jamie check your other post where I gave you the dimensions on my diff flange. If you cannot find a R 200 diff I will sell you one for $75.00 (out of a 77 5 speed) plus shipping. Quote Link to comment Share on other sites More sharing options...
pparaska Posted October 16, 2002 Share Posted October 16, 2002 TimZ, Yeah, I seem to remember hearing about using grade 5 instead of grade 8 for shear as well. Then I read Carroll Smith's books and I now use only AN or NAS bolts for REALLY critical shear bolting. I tend to use Stainless Steel elsewhere, or grade 5. I agree that the Nissan driveshaft/halfshaft bolts are great for this application as well, if they have enough unthreaded length. BTW, I used the 2.00" pilot R200 flange (couldn't find the 2.25" pilot one that the NEAPCO/SPICER flange mates to). I had a custom flange yoke made from a GM tranny slip yoke and a steel plate. The think I like about this setup is that the bolts are 10mm, not 8. I used some shim stock curled into a cylinder to take up the slack between the 10mm hole in the R200 flange and the 3/8" bolts I used (NAS 16 series). The holes in the flange yoke are right at 3/8". Miniscule slop, even when the bolts are loose. Quote Link to comment Share on other sites More sharing options...
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