Miles Posted August 1, 2005 Share Posted August 1, 2005 My Z started making noises like a U joint flange had come loose so I inspected each joint and found that the left flange that connects to the left stub axle was just flopping around. Removal of the flange revealed that the staked nut had sheared off right where the threads meet the splines. I had a spare stub axle so I drove out the broken axle and installed the spare. The original broken axle had a larger diameter threaded section then the replacement and it used the staked nut. The replacement used a nylock nut. The replacement also had a copper bushing and the original axle didn't. I installed the copper bushing with the replacement stub axle. When I test drove the car I could hear scraping noise coming from the left rear and I assumed that the drum was rubbing on the backing plate. Inspection showed that the drum was rubbing in two places so I bent the backing plate away from the drum and thought the noise would be gone. The scraping noise is still there, but not as bad. The scraping noise gets worse when making a right hand turn. I didn't replace the bearings since I knew the history of both stub axles and never had a problem. What could be causing rubbing noise - backing plate, bearings, nut not torqued tight enough? Thanks Miles Quote Link to comment Share on other sites More sharing options...
blueovalz Posted August 1, 2005 Share Posted August 1, 2005 First off, thank you for explaining your situation very well. Many times we get "I have a noise" and that's the extent of information given. As for what I know about stub axles, it includes this. The original broken axle had a larger diameter threaded section then the replacement and it used the staked nut. The replacement used a nylock nut. All the threaded parts of the Z stubs had the same threaded diameter. Splines will differ slightly, but the threaded portion is the same on all the Z stubs. To get away from the staked nut, many of us use the ZX nuts (which again, are the same diameter) which are not nylock, but instead all metal locking flange-nuts. Can I assume that your new stub has no provision for staking (I can't imagine that it wouldn't, but thought I'd throw that out)? My only guess as to the scraping noise could be two things. 1) if the scraping noise from the drum rubbing the backing plate did not exist prior to the swap, then I could only assume that the new axle is bent in that the wheel flange that the drum fits on is not true. 2) if you know the axle is true, then perhaps the grease seal dust guard is rubbing and needs a little more clearance (perhaps an additional washer between the companion flange and the bearing where the copper washer is) Quote Link to comment Share on other sites More sharing options...
JMortensen Posted August 1, 2005 Share Posted August 1, 2005 Sounds to me like your first stub axle was loose. I'd be SURE that your new axle is tight. The copper washer doesn't affect where the stub axle sits with respect to the brake hardware, so another washer shouldn't affect this situation. In fact, it doesn't do much at all. From another post: The copper washer is positioned directly under the companion flange on _top_ of the inner wheel bearing (not underneath it) so it does not add to the spacer length. So what does the copper washer accomplish? Well' date=' according to Nissan Technical Service Bulletin #TS72-06 (dated Jan 12, 1972), the copper washer was added to “absorb metallic noise originating in the rear axle of some 240Z’s.†It’s interesting to note that Nissan recommends that the tightening torque of the bearing locknut should be reduced from 180 to 240 ft-lbs to 95 to 125 ft-lbs when the copper washer was added. There’s more. Nissan Technical Service Bulletin #TS74-091A (dated Oct 3, 1974) states “the copper washer has been eliminated from the 280Z modelsâ€. The tightening torque of the bearing locknut was reinstated to be from 180 to 240 ft-lbs. No explanation of why the washer was no longer needed is given. Based on this, I would conclude that if you come across the copper washer during disassembly, then you can remove it and torque the bearing locknut to the “traditional†value of 180 to 240 ft-lbs.[/quote'] I like Terry's suggestion that the new stub could be bent. It's not good news, but it seems like a fairly plausible thing to happen. Since you were able to change it by bending the brake backing plate, I'm thinking that a bent stub is the problem. When I installed new bearings last week I bottomed the inner bearing in the strut housing and ran the seal all the way down to it. There was another post from somebody on either this forum or classiczcars.com where the guy hadn't gotten the inner bearing and seal all the way in and the lip on the seal hit the dust flange which made the stub axle difficult to turn. I don't think it would cause a grinding noise though. Quote Link to comment Share on other sites More sharing options...
Miles Posted August 1, 2005 Author Share Posted August 1, 2005 Terry Thanks for the quick reply. I was thinking that the companion flange dust cover might be rubbing on the stub axle housing and that adding a washer might help. Also, the axle I used did come out of my son's V8 240Z that he slid into a curb damaging the lower control arm. The axle spun free in the housing before I removed it and it spun free after I installed it in my car. I suppose that the axle could have a slight bend that doesn't show up until it is under load and at high rpm. Interesting point about the threads. I did some research and found that the splines differ for the 240Z and the 280Z. On the axle I removed from my car the splinned section of the shaft appeared a little larger then the spare axle and there were flat spots fore staking. The spare axle that I used has a round threaded section and no flat spots. Miles Quote Link to comment Share on other sites More sharing options...
JMortensen Posted August 1, 2005 Share Posted August 1, 2005 Thanks for the quick reply. I was thinking that the companion flange dust cover might be rubbing on the stub axle housing and that adding a washer might help. Also' date=' the axle I used did come out of my son's V8 240Z that he slid into a curb damaging the lower control arm. The axle spun free in the housing before I removed it and it spun free after I installed it in my car. I suppose that the axle could have a slight bend that doesn't show up until it is under load and at high rpm.[/quote'] I think it's much more likely that you would bend the axle at the flange, not where the bearings are. If the flange is bent it would spin freely. Quote Link to comment Share on other sites More sharing options...
Miles Posted August 1, 2005 Author Share Posted August 1, 2005 I found this website that shows some photos of the 240Z and 280Z stub axles for comparison: http://www.magshooterz.com/280z_stub_axle_swap.htm Miles Quote Link to comment Share on other sites More sharing options...
Miles Posted August 1, 2005 Author Share Posted August 1, 2005 I'll try taking some measurements at the flange as it rotates to see if it is out of alignment. If the flange is out of alignment I might as well get a replacement stub axle and replace the bearings too. Can the inner bearing be removed and replaced with the strut assembly in the car? The outer bearing I'll take to a machine shop and have the old one removed and a new one pressed on. Miles Quote Link to comment Share on other sites More sharing options...
johnc Posted August 1, 2005 Share Posted August 1, 2005 Can the inner bearing be removed and replaced with the strut assembly in the car? Yes, I've done it at a race track. Use a brass punch or bar to carefully tap the old bearing out and clean inside the hub. You have to be very careful tapping the new bearing in place. Make absolutely sure its going in square to the hub. Try to find a short length of pipe that just fits the outside bearing race or very carefully use the brass punch. Quote Link to comment Share on other sites More sharing options...
Miles Posted August 12, 2005 Author Share Posted August 12, 2005 The used stub axle I installed turned out to have a slightly bent hub from when my son slid his V8 240Z into a curb. Visually, you couldent tell it was bent, but on the car under load it caused the brake drum to wobble enough that it rubbed on the baking plate dust guard. It also caused the drum to drag on the shoes at one specific spot. I got tired of searching junk yards for another used, and potentially weak, stub axle so I called my Nissan dealer and bought a new stub axle with a set of inner/outer bearings and a grease seal. The stub axle ran about $250.00. The dealer installed the parts for $190.00 which I thought was very reasonable since I would have had to hunt up the tools and have a machine shop remove and press on the outer bearing. Total shop time was about 2.5 hours. Next month I plan on replacing the right side stub axle with all new parts. Victoria British also sells the stub axle for about $275.00. Miles Quote Link to comment Share on other sites More sharing options...
blueovalz Posted August 12, 2005 Share Posted August 12, 2005 Another happy ending! Quote Link to comment Share on other sites More sharing options...
Z-Gad Posted August 12, 2005 Share Posted August 12, 2005 Wow $250 per stock stub axle huh... whew... , so ~ $500 for the pair might have been worth considering a billet set from Ross for < $200 more http://www.modern-motorsports.com/catalog/product_info.php?products_id=62 Oh well, as blueoval said. "Another happy ending" Quote Link to comment Share on other sites More sharing options...
Miles Posted August 12, 2005 Author Share Posted August 12, 2005 I had considered the stub axles from Ross, but it was out of my budget and it would be over kill for a stock daily driver. Miles Quote Link to comment Share on other sites More sharing options...
jack46 Posted August 13, 2005 Share Posted August 13, 2005 I thought the spacer stayed with the assembly not the stubshaft? I was told the copper spacer was to correct variance in assembly. and ensured proper loadong of bearing. Quote Link to comment Share on other sites More sharing options...
blueovalz Posted August 13, 2005 Share Posted August 13, 2005 What you're thinking of is the large, long, steel spacer (it's more a tube) that fits between the bearings to keep the inner races on par with the outer races when everything is buttoned up. Quote Link to comment Share on other sites More sharing options...
jack46 Posted August 17, 2005 Share Posted August 17, 2005 What you're thinking of is the large, long, steel spacer (it's more a tube) that fits between the bearings to keep the inner races on par with the outer races when everything is buttoned up. I was referring to The replacement also had a copper bushing and the original axle didn't. I installed the copper bushing with the replacement stub axle.Miles Quote Link to comment Share on other sites More sharing options...
blueovalz Posted August 17, 2005 Share Posted August 17, 2005 Okay. The copper "bushing" is in reality a copper washer, and from my understanding and experience is not necessary for proper preloads on the assembly. I've yet to hear an explanation as to why some assemblies have it and others do not. Quote Link to comment Share on other sites More sharing options...
johnc Posted August 17, 2005 Share Posted August 17, 2005 From my experience disassembling the rear hubs on 240Zs. I've only seen the copper washer on later models of the 240Z (1972 and 1973) and its always on both hubs of the same car. I'm not positive that its used as a spacer (why use something as soft and as expensive as copper), maybe its more like a crush washer that helps with assembly during vehicle production. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted August 17, 2005 Share Posted August 17, 2005 From my experience disassembling the rear hubs on 240Zs. I've only seen the copper washer on later models of the 240Z (1972 and 1973) and its always on both hubs of the same car. I'm not positive that its used as a spacer (why use something as soft and as expensive as copper), maybe its more like a crush washer that helps with assembly during vehicle production. I've yet to hear an explanation as to why some assemblies have it and others do not. Post #3 give the reason for the copper washer straight from the FSM. It is to reduce metallic noise from the axle, and it's use was discontinued after a couple years. It is not used as part of the bearing spacer. Quote Link to comment Share on other sites More sharing options...
blueovalz Posted August 18, 2005 Share Posted August 18, 2005 Once again I've been enlightened! Quote Link to comment Share on other sites More sharing options...
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