John C Posted October 12, 2000 Share Posted October 12, 2000 I need to know what year cv joint and largest stub shaft combo will fit my 71 240? I have located a 79 280zx with cv's. Will the stub shafts and cv's work? My 240 already has an r200 ceter. Thanks. Quote Link to comment Share on other sites More sharing options...
Guest scca Posted October 12, 2000 Share Posted October 12, 2000 it will fit with all the ZX shafts but IMO the clearance isnt enough endplay. you need to make an adapter or use the ZX spindle flange. you need to almost take the rear arm out to get the shaft in.. the better way would be to fabricate an adapter to convert the regular 4hole to the new 6 bolt circle. ------------------ Mike http://www.fonebooth.com raceparts and brakeupgrades Quote Link to comment Share on other sites More sharing options...
pparaska Posted October 12, 2000 Share Posted October 12, 2000 I didn't know any 79's came with CV shafts. I thought is was only the 81-83 Turbo models. Yeah, endplay is scarce, but there are a few cars with this conversion (using 240Z stub axles, and modified (dust sheild) 280ZXT companion flanges) with the 280ZXT CV halfshafts and no ill effects. I've had both swaps on my 240Z, both the 240Z stub axle/280ZXT companion flange conversion and the 280Z stub axle, 280Z companion flange, and custom adapter. See this site or my site for tech articles. On my car, with the 240Z stub axle conversion, there is was slight binding only at the last 1/8" of droop of the suspension travel. I doubt that would have been a problem. This is not always the same car to car. I think it has to do with build and assembly tolerances. If the diff is moved to the left to much in the mountings, the left axle could have a binding problem. There is some play in the mounting, so if I were setting a car up like this, I'd try to get the diff pushed over to the right of the car as I was bolting it all together. I know that Greg Kring had big problems with the left shaft binding when he tried this conversion. With the 280Z stub axle version of the conversion there was no problem with endplay. But there is only a 1/4 inch of end play at full droop. Plenty in my opinion. I think it was Scottie who has converted his car using a customized 280Z companion flange. With a piece of plate welded onto the companion flange, and the 6 holes for the CV shaft drilled into it, the shafts don't have to be compressed as much and there is no problem with endplay. To get the CV shafts in and out of either of the conversions I did, you have to either tak the control arm loose (inside is easier than outside joint, generally), or undo the struts at the top and swing them out. I usually do the latter if I'm not taking the diff out for some reason. For Scottie's welded adapter, I'd bet you could swap the halfshafts out without undoing the suspension. Scottie? comments? ------------------ Pete Paraska - 73 540Z - Marathon Z Project - pparaska@home.com">pparaska@home.com - Quote Link to comment Share on other sites More sharing options...
Scottie-GNZ Posted October 13, 2000 Share Posted October 13, 2000 The passenger side is a tight fit to get on w/o undoing the strut. It can be done, but I find it easier to just unbolt the 2 bolts at the front of the control arm to give me the little clearance I need. Once in place, I did the following to test the clearance. I jacked up the outer end of the control arm to the point where there was the most compression on the CV. I then used a prybar at the diff end was able to get another .5+" compression. Of course the big test is my launch off the line with t-brake Cannot imagine anything worse except putting a wheel in a big pothole and then binding is the least of your problem ------------------ Scottie 71 240GN-Z http://www.mindspring.com/~vscott911/gnz.html Quote Link to comment Share on other sites More sharing options...
pparaska Posted October 13, 2000 Share Posted October 13, 2000 I just wanted to clarify. The binding that I had at full droop was an angularity problem with the inner joint. It may have had something to do with end play and the severe angle the joint had at full droop. Note that this was with the differential mounted about 1/2" above the stock location at the rear which agrivated the problem. Quote Link to comment Share on other sites More sharing options...
Guest scca Posted October 13, 2000 Share Posted October 13, 2000 i am more concerned with the end play under load... what i thought was if it is so close to put the shaft in how much endplay/clearance is left under a hard corner. as the strut compresses the shaft must shorten can you install the strut without a spring and get full travel up without binding and still have endplay? ------------------ Mike http://www.fonebooth.com raceparts and brakeupgrades Quote Link to comment Share on other sites More sharing options...
pparaska Posted October 13, 2000 Share Posted October 13, 2000 Mike(scca), the reason you had to disassemble the suspension to get the shaft it is bacause the end of the CV shaft has a seal plate with a cone in the center of it that sticks out from the end of the outer joint. To get that cone to clear the outer diameter of the adapter (for the 280Z stub axle conversion I have on the car now) or the 280ZXT companion flange (for the 240Z stub axle conversion) you had to move the companion flange out from the center of the car. Once the CV joint was mated with the companion flange or the adapter (depending on which conversion I had in place), there was some endplay available. with the suspension in droop, probably 1/4", but I didn't measure. What I did was bolt the suspension back in without a spring and tested for bind through the entire movement of the suspension. The only place I got any bind was full droop with the 240Z stub axle/280ZXT companion flange, and that was really more of an interaction of the extreme angle the CV was at combined with the shaft being compressed so much. In other words the outer joint was compressed to the point that as I turned the axle, the top trunion on the CV was probably running out of room to slide, but only in the last 1/8" of droop, with 1.5" shortened struts and a .5" raised diff. Stock length struts would have more droop and the CV angle would be more severe, I'd think so you would probably have trouble with that. There is an issue there. With the adpaters and the 280Z companion flanges and stub axles, I did not have this problem. In looking at the stub axles, I'd think that a rebuilder could have the shaft shortened on the outer end, even by 1/4" and have the splines extended toward the other end of the shaft the same amount, thus shortening the shaft. This doesn't seem like such a big deal, since you might want to have the boots replaced anyway, and for that the trunion has to come off the outer end of the shaft anyway. Finding someone to respline a shaft is not a huge problem - the hotrod guys do it all the time with shortened rear axles. I think this would alleviate any concerns about end play for little trouble and money. I will give Mardi at Raxles a call about this . He's a pretty good guy and into this sort of stuff. Quote Link to comment Share on other sites More sharing options...
Guest scca Posted October 13, 2000 Share Posted October 13, 2000 if it was relatively cheap to respline it may be a better thing to shorten the axles 2" or ?? and use the ZX companion flanges so everything else bolt in... would be nice to decide which way is best . i've parted out 2 ZXT cars so i have all the stuff to do it- i was going to make the adapter plates- maybe its something to get 10 prs or so made at once? ------------------ Mike http://www.fonebooth.com raceparts and brakeupgrades Quote Link to comment Share on other sites More sharing options...
BLKMGK Posted October 14, 2000 Share Posted October 14, 2000 I'm interested in the CV conversion. If someone figures out a way to package it such that each of us don't have to do our own engineering and adapter building it would be great! There has to be bunches of us who wouold be interested in getting resplined axles etc. to alleviate fitment issues and a set of spares never hurt either. So Mike if oyu're considering it count me as an interested party... Quote Link to comment Share on other sites More sharing options...
Guest scca Posted October 15, 2000 Share Posted October 15, 2000 if there can ever be a consensus reached as to whats the best way to go i can check with the machine shop and likely get a good price on them...i cant get resplining done real cheap yet and i do like the idea of getting refurb shafts over the counter more than the shortening idea.... but who knows..... those that made adapters what do you think it cost... or rather what would it cost to duplicate again- just like scotty does for the turbo DP-- maybe one day i'll get one- when he has 10 people to do it again... Quote Link to comment Share on other sites More sharing options...
pparaska Posted October 15, 2000 Share Posted October 15, 2000 I called Mardi at Raxles.com. A quick look showed that the "stick" (the shaft portion) of the halfshaft on the left side was the shortest he knw of before getting down to something 2" shorter. He didn't think that would work. He mentioned that he could order custom length sticks, but needed to do a run of 30. I told him there might be a buyer for a set of 30, but I wasn't sure. That way, we could use the joints from the left shaft with this custom stick to make up an appropriate length shaft for the left side of the 240/260/280Z that would get away from this endplay issue. It's an easy thing to shorten the right side halfshaft, as you could put the 1/2" shorter stick from the left haflshaft between the joints of the right halfshaft. He said he'd look some more to see if there was something less than 2" shorter than the stick for the left halfshaft. Quote Link to comment Share on other sites More sharing options...
BLKMGK Posted October 16, 2000 Share Posted October 16, 2000 Here's an ignorant suggestion - would it possible to use shafts of the same length and then just use custom shafts on both sides? We'd only need 15 people then and both sides would be as strong as the other. Is that feasible? The adapters seem to be one of the sticking points too. BTW FWIW - hopped up IRS Cobras are breaking shafts and CVs left and right. Just saw a new Cougar in the shop getting new CVs too - owner NOS'ed it one time too many! Don't forget to look at the VLSD page - would the shafts he found be any sort of option or are they too different? Just tossing out ideas - I know diddly about the rear suspension but would like to make mine as storng as possible (sigh). If I tear mine up too badly I may wind up looking at a Vette' rear - Ouch$! Quote Link to comment Share on other sites More sharing options...
pparaska Posted October 16, 2000 Share Posted October 16, 2000 BLKMGK, the shafts are different in length by a half inch I BELIEVE. That might be an option. There is quite a bit of throw on the outer plunge joints. Mardi at Raxles was talking about those Cobra halfshafts. He said the guys at Ford tapered the shaft down too quickly coming out of the joint and that he has been making replacement halfshafts that use a shaft that's either not as tapered or not tapered at all (I can't remember.) He said he gets alot of broken shafts in from those cars. He said that the SVT guys weren't in on that part of the design, which surprises the hell out of me. John Thagard's VLSD page is: http://www.eng.fsu.edu/~jthagard/vlsd.htm He says it's the 84-89 AMC Eagle 6 cylinder front CV shaft. I don;t know if it will work, because the diff side joint might be different on the VLSD halfshaft. The case and shaft that go into the VLSD are different than the LSD parts. [This message has been edited by pparaska (edited October 15, 2000).] Quote Link to comment Share on other sites More sharing options...
John C Posted October 21, 2000 Author Share Posted October 21, 2000 Thanks for the info guys,but I still have a question on the axle stub size. I picked up an early 280z,76 I think and I want to know if the stub is larger at the bearing surface?I understand it has a 27 spline instead of the 240's 25. I would like to have the largest,strogest stub shafts possible . Thanks. Quote Link to comment Share on other sites More sharing options...
pparaska Posted October 23, 2000 Share Posted October 23, 2000 JOhn, I'm pretty sure the axles are the same except for the splined area. Check a catalog, (I don't have one here) to see if the bearings are the same between the 240Z and the 280Z. I'm 99% sure they are. That would clinch it as them having the same diameter at the bearing races. Remember, the other area the stub axles fail is at the friction weld between the flange and the shaft for the stub. It seems some racers are beginning to inspect this once a year and even magnaflux the area. Quote Link to comment Share on other sites More sharing options...
Guest scca Posted October 24, 2000 Share Posted October 24, 2000 the ones i have seen broken all broke at the splines next to the nut. i've seen it 4 times. (every time a v8 car) you unbolt the 1/2 shaft and the nut falls out with the shaft attached - at least part of it..... i changed all to the larger spline shaft and not as much a problem. hard to determine though. was it the age of the shaft or the thickness. or that the replacement shafts came from a auto car that hadnt had the crap beaten out of it over time? lots of factors to consider .. back in my 510 days the best cars to build were little old lady 2dr autos as they had the least abuse overall. ------------------ Mike mike@fonebooth.com http://www.fonebooth.com/brakes.html raceparts and brake upgrades. Quote Link to comment Share on other sites More sharing options...
John C Posted October 25, 2000 Author Share Posted October 25, 2000 Thanks for the info guys. I am gathering stronger parts now in case I need them next year.I guess I can count myself very lucky since there hasn't been any rear suspension breakage yet. John Quote Link to comment Share on other sites More sharing options...
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