Pop N Wood Posted February 23, 2003 Share Posted February 23, 2003 There shopuld not be any question which is stronger, its just a matter of looking at the two to determine there is MORE contact material on the CV then the universal setup. Also. for that matter, I would NEVER consider running that shaft on my car, and last dyno pull got mr 473 fppt pounds of torque in 4th gear. Would any of you like to try that with the universal type half shaft and really depend on it?? You do realize the vettes and peterbuilts use U joints? Your argument is not really valid. Quote Link to comment Share on other sites More sharing options...
stony Posted February 23, 2003 Share Posted February 23, 2003 much bigger ujoints i might add. if we could mod our shafts to accept bigger ujoint like that we would have no problems ;> Quote Link to comment Share on other sites More sharing options...
jeffp Posted February 23, 2003 Share Posted February 23, 2003 Yes I do realize the different type shafts and I am aware of the factthat the universal joints used in the other cars are much larger then what Nissan uses and there in lyies the problem. Its just simply a matter of the amount of material used in the universal. When you look at the two side by side it is clear the GM part is much beefier, and stronger. We are talking about Nissan parts here. Further, in my opinion I would much rather have a universal joint type coupler with the rollers in a 120 degree pattern using three contact surfaces then the standard universal joint coupler in the 180 degree pattern with only two contact points. You will get a better transfer of power over a range of angles that the standard universal joint, although will work, with less probibility of breaking. The fact is that once you get past a certin degree of angle on the universal joint the more torque is put on the part that makes breaking the part easier, but with the three universal joint configuration, you will maintain the torque better as there is more contact areas to handle the angle and they share in the angles making it much stronger. anyway, go with the zxt setup and you wont be unhappy about doing the mod. Quote Link to comment Share on other sites More sharing options...
Pop N Wood Posted February 24, 2003 Share Posted February 24, 2003 go with the zxt setup and you wont be unhappy about doing the mod. Yeah, I am starting to understand. I just didn't feel like incurring yet one more expense. Now that I understand where everyone is coming from, I am sure my near stock ride height Z should be OK with the U joints on a near stock LT1. And if I ever have problems then it will be time to upgrade. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted February 25, 2003 Share Posted February 25, 2003 Ok folks, I think I may have gotten a lucky break in this. Here's what I'm gonna do: It turns out that I have an uncle by marriage who OWNS a CNC-equipped machine shop not too far from me. I talked to him a couple of days ago about the feasibility of making some shafts, and he thought it would be a good idea. So, I'm gonna carry a spare stock ujoint shaft down there this weekend and we'll have a look at it. He has suggested that using stock parts from some other application and modifying them as necessary might be the way to go. I agreed with that. One potential sticky point is the part of the stock shaft that lets it change length-that thing uses ball bearings and has compound curves for them to ride in. Not easy to duplicate at all. I'm thinking that since the shaft has a joint at both ends, there shouldn't be much lateral stress along the middle of the shaft. If that's the case, then some sort of splined arrangement where one half slips into the other (like how a driveshaft slips onto the output shaft of a transmission) might work, and be much easier to make. I'm gonna keep mum about what stock parts I might base this off of for now, as it's way too early to know for sure what I'll end up using. But, I will say that if that part of the process goes the way I hope it will, I could end up with something ridiculously strong compared to what any z car would put it through. I do know that his shop has a lathe, drill press, and a number of other tools. I also know they can cut splines. Beyond that, I'll just have to wait until this weekend before I can make much progress. Quote Link to comment Share on other sites More sharing options...
stony Posted February 25, 2003 Share Posted February 25, 2003 heres what i did. i took the z31300z stub shafts and modded the struts with the correct bearing to accept the stubs. i was gonna try and get a custom set of stub shaft flnages made for the inner side but the machinist up here in alaska wanted 500 bucks a pop. so i decided to go with custom length axles (400 for set) . if you could have these inner pieces custom made you could use teh stock z31 axles withough modding them and have a pretty strong setup. Lets go one step further.... z32 rear end could be done the same way i believe and that would be even a stronger setup. one step further would be the gtr rear rearend axles. Ive seen alot of 800HP gtrs hammering those rears and nothing ever breaks. all this and still retain teh IRS rear Quote Link to comment Share on other sites More sharing options...
j260z Posted March 1, 2003 Share Posted March 1, 2003 let me see if i have this clear stony. you took the stub axles from a 300zx and found new bearings for them so you didn't have to do any machining to your struts? you then shortened the shafts on the 300zx cv's and used the stock 300zx companion flanges? if this is so then i should be able to use the stub axles from a 86 300zxt and get a five bolt pattern without many mods and have a strong setup correct? Quote Link to comment Share on other sites More sharing options...
stony Posted March 1, 2003 Share Posted March 1, 2003 no i did mod the struts. the s30 had standard size bearing and the z31 had metric so there is no way to get a set of bearings that wont require any mods. i had tapered bearings and races installed in the struts (which need to be machined so the bearing would fit) then used the stubs, companion flanges, and a set of custom length 300z z31 chromoly axles, and the r-200 LSD diff from the same car. i still have to make the brackets so i can use the z31 rear calipers. but when its done the mod will have cost about 1000.00 for everything. I did get the z31 parts for pretty much free. but i dont see the parts costing more then 3-400 bucks from a junk yard. Quote Link to comment Share on other sites More sharing options...
j260z Posted March 1, 2003 Share Posted March 1, 2003 as far as brakes go, i was looking at the 240sx kit from ross at mml. do you know if your rotors are in the same position as they were before in relation to your caliper mounts? Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted March 11, 2003 Share Posted March 11, 2003 Ok, I think I've narrowed down my list of possible components. Here's what I'm looking at so far: Picture two transmission yokes end to end, with the splined sides facing each other. Now, the outer ends have ujoints, with some sort of flange to mate to the differential flange and the wheel flange. A solid splined shaft, made from steel bar stock is in the middle of all this, between the 2 transmission yokes. The yokes are slid up on this shaft, thus providing the length adjustment necessary to accomodate suspension travel. The transmission yokes aren't just any old transmission yokes. Since they'll be dealing with rearend-multiplied torque, not just driveshaft torque, they're 1 1/2 ton truck transmission yokes. I think those will get the job done-they're a good bit thicker than any passenger car transmission yoke I've seen, and the ujoints these use are both big and cheap. The joints absolutely DWARF anything that came on a datsun. I think they're a size bigger than 1350 joints, if that tells you anything. All of this is still up in the air, as I'm trying to find the cheapest parts that will be bulletproof. Since that doesn't involve starting with a known vehicle application, the normal parts-finding systems aren't much help. This setup would obviously require the use of 4 transmission yokes, 2 fabricated splined shafts, 4 ujoints, and 4 fabricated flanges to bolt to the respective flanges on the car. There's still a chance that this will fall through because of unforeseen financial reasons, but offhand I'd say it looks workable. I'll post more updates as they unfold. Quote Link to comment Share on other sites More sharing options...
jeffp Posted March 13, 2003 Share Posted March 13, 2003 I dont thing that is a good way to go on the rear stub axels for these cars. You will have to come up with some sort of pre load to keet the bearing in place and proper tolerances to the race. Taking into account that there is the side loading of the bearings from friction from the tires in a turn, it would seem to me the standard Nissan setup cage roler bearing would be much more suited to that application. You need the axel fixed and rotating true, you will be hard pressed to maintain that tolerance with a tapered bearing in that location on the axel. anyway, got to run just some thoughts. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted March 13, 2003 Share Posted March 13, 2003 I'm not sure I understand where you're coming from. I'm not talking about changing anything to do with bearings-I'm talking about making new halfshafts. They'll simply bolt to the stub flange on the differential and the wheel flange on the other end. Did I misunderstand you? Quote Link to comment Share on other sites More sharing options...
stony Posted March 14, 2003 Share Posted March 14, 2003 I think he is talking about my mod... we will see if it works in april i hope ;> Quote Link to comment Share on other sites More sharing options...
Doug71zt Posted March 30, 2003 Share Posted March 30, 2003 The Z31 shafts will fit with stock axle stubs - We've got 3 cars in our club running this set-up with no problems for 3 years now. You have to make an adapter for the outboard end of the shaft but it's not rocket science. To avoid the big cost for the adapter - start with the stock Nissan Ujoint adapter - chuck it in the lathe - machine off the flange a little below the OD of the adapter to make a step. Next get a ring burned out of 3/8" steel that fits the od of the CV and the id of the adapter flange - I made mine a press fit and pressed them together. Then weld both inside and outside around the flange. I got rid of the dust cover on the adapter in order to get a good bead around the outside. You can tack it back on after you're done. Chuck it back in the lathe - face the CV flange face and machine out the locating step for the CV. Transfer the CV hole pattern. You're almost there. I trimmed the end of the stub axle and used a 280Zx nut as I have 4130 lower control arms which are adjustable and I didn't want any interference in the CV shaft because my control arms are narrower than stock for camber adjustment. Now for the CV shaft - Take the outer joint off - disassemble it and turn the inner coupler (the star) around - It's offset to the outside in a Z31 which makes the shaft longer. In the earlier cars - you want the shaft shorter. I trimmed the end of the CV shaft outside the snap ring groove to prevent interference with the grease cover for the reason outlined above - I think I left about 1/16 of an inch outside the snap ring groove. Re-assemble outer CV and install. I used 280 stub axles because the splines are bigger and there are more of them. I have done this - Its cheap and it works. If I ever break these CV's - I'll be surprised. Way tough compared to the 280 ZXT joints. Now - about the welded adapters - I have had comments like the weld makes a weak point in the adapter. BS - We all have driveshafts that are welded at both ends - no problems with those. Just make sure its a quality weld. I know I have a slight advantage on most when it comes to doing this because I have access to a machine shop - But total cost on the coversion was about $100 Canadian. Z31 parts are dirt cheap because there is no call for them. Sorry about the length of the post but I wanted to make this known. Good luck - Doug Quote Link to comment Share on other sites More sharing options...
Guest Carrman Posted March 30, 2003 Share Posted March 30, 2003 Sounds like we need pics and a tech article on this conversion! Quote Link to comment Share on other sites More sharing options...
stony Posted March 30, 2003 Share Posted March 30, 2003 mine should be done in a week or so i will take pics as i reassemble. mine was a little expensive but i dont have the s30 stubs anymore ... i modded the struts to accept z31 stubs and made custom length cv axles. I was going to do the above mod but did not want the next weak link to be the stubs that was kinda scary to me ;> more to come Quote Link to comment Share on other sites More sharing options...
j260z Posted March 31, 2003 Share Posted March 31, 2003 i have a set of the z31 turbo shafts they have the 4 bolt flange and are ball and cage. i know the z31 NA shafts have the 6 bolt flange but are they also a ball and cage or a tripod style? I would have to assume the NA and turbo shafts would be the same length? correct me if i'm wrong Quote Link to comment Share on other sites More sharing options...
Doug71zt Posted April 1, 2003 Share Posted April 1, 2003 J260z - If they are six bolt flanges they are tripod type. I used the turbo shafts because of the stronger joints. I would assume that's why Nissan used them in the turbo cars. Now that I have a digital camera - I may be able to get time to do up a tech article soon. A little hard to do right now as I'm in Cyprus right now and the car is in Canada. Let me tell you though - the smoothness of the drivetrain under power is unbelievable compared to ujoints. Cheers - Doug Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted April 1, 2003 Share Posted April 1, 2003 i called a place in houston who rebuilds c/v's and he told me that they use exactly the same material as the stock ones use. Quote Link to comment Share on other sites More sharing options...
Scottie-GNZ Posted April 1, 2003 Share Posted April 1, 2003 I sure hope you can trust them. I have a friend who manages one of the large CV repair franchises and he advised that I was better off taking a chance with used OEMs because the rebuilds did not use quality metal for the cages. They are certainly good for a normal driving replacements but would definitely not hold up to racing. Quote Link to comment Share on other sites More sharing options...
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