CrayZ Posted January 14, 2013 Author Share Posted January 14, 2013 I think the best options is to take the springs out and reinstall the axles with boots off to watch the travel and where the bearings are.. You guys are right I just need to take a little time and do some looking. Quote Link to comment Share on other sites More sharing options...
CrayZ Posted January 14, 2013 Author Share Posted January 14, 2013 I wish I had a local shop or someone with experience with these rear ends local to me. Quote Link to comment Share on other sites More sharing options...
CrayZ Posted January 14, 2013 Author Share Posted January 14, 2013 (edited) Quick question. If the wheel is fully compressed Inside the wheel well (axle being at its shortest) how will I know the proper clearance? When sliding the axle left and right will the axle hit the hub side bump stop before the diff side bearings reach the c clip? Is that how I know they are the proper length? Is there a certain formula or distance the opposing ball bearings need to be from the c clip when the axle has reached the opposite bump stop? Edited January 14, 2013 by CrayZ Quote Link to comment Share on other sites More sharing options...
CrayZ Posted January 14, 2013 Author Share Posted January 14, 2013 Oh and I can't seem to keep a set of rubber boots together.. Is this not an immediate sign that the angle of the driveshafts is to steep? Quote Link to comment Share on other sites More sharing options...
CrayZ Posted January 15, 2013 Author Share Posted January 15, 2013 (edited) Full droop no spacer: http://s484.beta.photobucket.com/user/texastrini1986/media/A4560D6B-8357-4ED3-9351-0A0F37A48C10-8623-00000A65EF1F3759.mp4.html Fully compressed no spacer: http://s484.beta.photobucket.com/user/texastrini1986/media/FB67C75A-6657-4647-BE55-43322D1F08A8-8645-00000A699EA94CF9.mp4.html Full drop W/Spacer: http://s484.beta.photobucket.com/user/texastrini1986/media/AEA18D87-B935-46D1-B249-1B35A3B21C8A-8645-00000A6E77836F56.mp4.html Fully compressed W/Spacer: http://s484.beta.photobucket.com/user/texastrini1986/media/92915C57-AA52-4593-A335-EA637C18CF21-8668-00000A71B0D55B74.mp4.html No idea why it is grinding down the hub side stop and no idea how the bearings could be making there way past the ring on the hub side.. The diff side seems to be intact.. I know it is a bit hard to see in the last video but IMO the ball bearing really dont even get close to the where the clip would be. Now i did not take the springs out so there could be more travel but not more than 1/2" I just dont think there would be enough to allow the bearings to come past the c clip.. Edited January 15, 2013 by CrayZ Quote Link to comment Share on other sites More sharing options...
rossman Posted January 15, 2013 Share Posted January 15, 2013 So the cups separated from the ball bearings with the spacers installed? Seems impossible unless something is loose. Are you positive the differential and suspension mounted solid? Something may be moving or deflecting under load. Quote Link to comment Share on other sites More sharing options...
CrayZ Posted January 15, 2013 Author Share Posted January 15, 2013 Yup, They rounded off the ends of the cups.. The rear end is solid as a rock. It just doesnt make sense to me.. hub side bump stop chweed to crap AND the cup was rounded off.. Quote Link to comment Share on other sites More sharing options...
CrayZ Posted January 15, 2013 Author Share Posted January 15, 2013 After further inspection i found all the ball bearings/cages to be intact. The only thign that was strange was the little star peice that sits inside the cage has wedged itself pretty good down the axle. I had to knock it loose with a hammer.. Quote Link to comment Share on other sites More sharing options...
CrayZ Posted January 15, 2013 Author Share Posted January 15, 2013 So the cups separated from the ball bearings with the spacers installed? Seems impossible unless something is loose. Are you positive the differential and suspension mounted solid? Something may be moving or deflecting under load. Forgot to add that everything looks good as far as i can tell. Ive had the car 2 weeks now.. (me rolling my eyes) Quote Link to comment Share on other sites More sharing options...
NewZed Posted January 15, 2013 Share Posted January 15, 2013 Thanks for doing that work and posting those videos.It seems like the star/bearing race/cage walking down the shaft might be the problem, not a result of the problem. For whatever reason the star walks, pulling the balls with it. If the cage and star walk far enough inward, that makes the end of the axle get closer to the stops, effectively. After the star walks down the shaft, is it possible for the balls to be on the circlip and the end of the axle to be on the stop, binding the axle end and balls between the stop and the circlip, until one or both give? If you could lock the star in place at the end of the shaft it might solve the problem.Just a guess. I can't imagine that the star is supposed to move on those splines while in use. You might compare a stock Q45 shaft to the MM shafts and see if the star can walk on the stock shaft, and measure the distance from balls in the star wheel and the axle end, with the star walked inward, and see if it's longer then the cup can take. A fix might be as simple as peening some splines on the inside of the star to stop it from walking. As far as shaft length - I can see that I missed something when looking at the drawings and the shortest shaft may not be at full compression. The hub doesn't tilt when it pivots around the control arm axis, it stays essentially perpendicular to the ground. Two things happening, one pulling it away and one drawing it closer. Looks like pulling away wins based on your videos, the shaft is shortest with the wheels hanging (as jmortensen has said in previous posts). Thansk again, those videos show a lot. Quote Link to comment Share on other sites More sharing options...
CrayZ Posted January 15, 2013 Author Share Posted January 15, 2013 Thanks for doing that work and posting those videos. It seems like the star/bearing race/cage walking down the shaft might be the problem, not a result of the problem. For whatever reason the star walks, pulling the balls with it. If the cage and star walk far enough inward, that makes the end of the axle get closer to the stops, effectively. After the star walks down the shaft, is it possible for the balls to be on the circlip and the end of the axle to be on the stop, binding the axle end and balls between the stop and the circlip, until one or both give? If you could lock the star in place at the end of the shaft it might solve the problem. Just a guess. I can't imagine that the star is supposed to move on those splines while in use. You might compare a stock Q45 shaft to the MM shafts and see if the star can walk on the stock shaft, and measure the distance from balls in the star wheel and the axle end, with the star walked inward, and see if it's longer then the cup can take. A fix might be as simple as peening some splines on the inside of the star to stop it from walking. As far as shaft length - I can see that I missed something when looking at the drawings and the shortest shaft may not be at full compression. The hub doesn't tilt when it pivots around the control arm axis, it stays essentially perpendicular to the ground. Two things happening, one pulling it away and one drawing it closer. Looks like pulling away wins based on your videos, the shaft is shortest with the wheels hanging (as jmortensen has said in previous posts). Thansk again, those videos show a lot. No problem, I hope these videos will help me and others understand exactly what is going on behind the driver seat. As far as the star walking on the axle ends goes, having taken them apart 4-5 times now I'm pretty sure they are designed to walk slightly. I could be wrong but I don't think I am. With that said I think fixing them in place is a good idea. This could be blasphemy I don't know. If the star is wedging itself down the shaft and inturn popping the circlip out, that still doesn't explain the axle stops being ground to hell. Quote Link to comment Share on other sites More sharing options...
EvilC Posted January 15, 2013 Share Posted January 15, 2013 Mark - Rags - Sunny - 1tuffz mentioned what I am thinking and can speak from my own car. I have not seen a picture of your MM cv adapters. A spacer should not be needed. So recap here and moving forward. When doing this swap, buying the MM axles I went to the local junkyard and bought 4 Q45 axles to get 4 cv "cup" sections of the stock axles. I followed the install guide and bolted the setup together. The only issue I have had is like you showed - the axles stops being torn into by the axle. Like Mark said, it is a floating axle design so the stops are the only thing that stops the travel. You can have them turned down to the depth that the axle appears to be hitting them. There isn't any need for flipping cages, just be sure to have 4 of the same stock CVs. It is possible to have too much travel as 1tuffz mentioned in his case. Do you have camber plates? Adjustable rear control arms? I am curious that both 280z owners had the same issue. I would love if we on Hybrid were able to get a stock 240z and stock 280z and check rear end setups. It looks like the 280z has slightly more toe than a 240z. I will see if I can find any pics of my setup. Quote Link to comment Share on other sites More sharing options...
CrayZ Posted January 15, 2013 Author Share Posted January 15, 2013 (edited) All suspension is stock besides the ground control coilovers. Either spacers or longer axle are clearly needed in my application due to the ride height (check the videos). My dif sits quite low and as you can see. The angle of the driveshafts are quite extreme. The thing that gets me is that out of all the other lowered Z's I've seen my diff and axle angle is WAY lower and more extreme.. I don't understand why mine is so different. I would also like to add that the passenger side is in very good shape. The grease is fresh play within tolerance. I also measured to make sure that the springs where at the same length. Both rear springs are adjusted to the same height but the driver side (problem side) control arm actually sits about 1/2" higher than the passenger at full droop. I also noticed that the entire axle/dif setup seems to sit towards the driver side more by about an inch. It looks to be "offset" towards the left if your looking at it from the rear of the vehicle. I hope that makes sense. Edited January 15, 2013 by CrayZ Quote Link to comment Share on other sites More sharing options...
EvilC Posted January 15, 2013 Share Posted January 15, 2013 Sorry I can't see the video links because I am at work. Is it possible for you to measure the height from ground to the bottom of the diff? Does anyone think that some of the gap can be made up with adjustable control arms? Being able to pull the bottom of the strut housing more inboard. Quote Link to comment Share on other sites More sharing options...
CrayZ Posted January 15, 2013 Author Share Posted January 15, 2013 Sorry I can't see the video links because I am at work. Is it possible for you to measure the height from ground to the bottom of the diff? Does anyone think that some of the gap can be made up with adjustable control arms? Being able to pull the bottom of the strut housing more inboard. No worries, maybe you can check them out when you get home and tell me what you think. I will measure the distance from the ground to the bottom of the diff when I get home tonight. I also just remembered that the previous owner cut the struts and re welded them together to make the springs work. From what I've read this is common? I'm not sure if the fact that the rear end seems to be shifted towards the driver side is common? I'm also curious why the control arm seems to be sitting higher even with the springs being equal on both sides. Quote Link to comment Share on other sites More sharing options...
rossman Posted January 15, 2013 Share Posted January 15, 2013 I think a better reference for the diff height would be one of the frame rails or some other common hard point on the body of the car. This would eliminate differences in ride height when comparing to other s30s. Quote Link to comment Share on other sites More sharing options...
EvilC Posted January 15, 2013 Share Posted January 15, 2013 Ross is right, my 240 won't share a common hard point as your 280 maybe the distance between the top off the diff to the body right above it? Quote Link to comment Share on other sites More sharing options...
CrayZ Posted January 15, 2013 Author Share Posted January 15, 2013 Well I can tell you that the diff has about 1" before it touches the top. There is a square peice of "frame" or structure peice that runs parallel to the axles above the diff. The tallest part of the diff has about 1" of clearance before it makes contact with it. I don't possibly see how it could be raised up unless it was moved forward a couple inches. Quote Link to comment Share on other sites More sharing options...
CrayZ Posted January 15, 2013 Author Share Posted January 15, 2013 (edited) I'm going to check and see if the cups are lined up tonight. Maybe they are off center and I could find a way to mount the diff further forward and higher.. I'm pretty sure they are lined perfectly though. All the mounting holes are in line and square. I don't see how the diff could be further back than it needs to be. I know the previous owner made a custom lower diff mount but the big one that bolts to the rear of the diff is centered and mounted firmly and the rest of the mount kit is out the box stuff. Edited January 15, 2013 by CrayZ Quote Link to comment Share on other sites More sharing options...
NewZed Posted January 15, 2013 Share Posted January 15, 2013 (edited) Regarding the star "walking" on the shaft - it's either supposed to be free to move around, or it's supposed to stay in one place. But walking to a new spot and getting stuck so tight that you have to bang it off with a hammer can't be right. It's either a cause of the problem, or a result of the problem. Might be worth focusing on how and why that happens. If the balls were pressing on the circlip, that force would be pushing against the star and cage, preventing it from getting stuck on the inner spline portion. Since the star is stuck, that suggests that the star walked doen the shaft first, got stuck, then held the balls against the clip until it popped out. I've found that the weird small stuff is sometimes the clue to solving the big problem. Good luck. Edited January 15, 2013 by NewZed Quote Link to comment Share on other sites More sharing options...
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