pete280z Posted November 30, 2006 Share Posted November 30, 2006 I'm starting to believe that the "full service machine shop" up the street has no idea what they're doing. How tight should my rear axles be? The haynes manual talks about spring balances (no idea what that is) and the FSM gives me wheel bearing preload, but neither one are particularly helpful. So here's what I did to measure how tight these are: I put a lugnut on a stud and turned the axle with a torque wrench. It takes about 4 ft-lb to get the axle to turn at all. That doesn't sound like much, but it seems way too tight to me. Is this normal, or should I pull everything apart and check things out? For background, I dropped off stub axles and struts to have new bearings installed (I provided them). On their first attempt they assembled everything ungreased and trashed the grease seals. I took them the pages from the FSM and explained what I wanted. They installed new Nissan grease seals and greased the ever-living out of the thing. I wouldn't be surprised if the whole thing is packed full of this weird green-colored grease. Quote Link to comment Share on other sites More sharing options...
HB280ZT Posted November 30, 2006 Share Posted November 30, 2006 My FSM for my 77 280Z says 181 to 239 foot pounds of torque! Hope this helps HB280ZT Quote Link to comment Share on other sites More sharing options...
JMortensen Posted November 30, 2006 Share Posted November 30, 2006 4 ft lbs is too much. I'd be willing to bet that they didn't drive the seal all the way in, and the rubber seal is dragging on the stub axle dust flange. How tight you tighten the nut shouldn't make any difference in how hard it is to turn the stub axle, despite what the FSM says. Unless you're distorting the thickwalled steel spacer between the bearings inside, it just isn't going to make a difference. Quote Link to comment Share on other sites More sharing options...
naviathan Posted November 30, 2006 Share Posted November 30, 2006 It should be 2lbs to turn the axel according to the fsm. However when I put mine back together it was also a bit tight and I couldn't get it to the 2lb preload either. I think mine was about 4. It'll be fine so long as that nut is on tight and things don't come apart. I haven't had any issues and I did mine the begining of the summer on my DD. If they did pack everything full of grease it could blow that seal out the first time it gets hot. Grease expands and if there's too much it will build pressure. Hope that's not the case. Quote Link to comment Share on other sites More sharing options...
Sam280Z Posted November 30, 2006 Share Posted November 30, 2006 It can also bind if the bearings are not seated completly. Quote Link to comment Share on other sites More sharing options...
johnc Posted November 30, 2006 Share Posted November 30, 2006 How tight you tighten the nut shouldn't make any difference in how hard it is to turn the stub axle, despite what the FSM says. That may be true in theory but, having assembled at least a dozen rear hub sets, I can say that stub axle nut torque has a direct affect on how free the stub axle turns. Stub axle nut torque settings are anywhere from 185 to 240 in the units I've assembled. And I do use a fish scale to measure turning torque per the FSM. Remember, these are 30+ year old parts with bearings and seals from various suppliers. EDIT: To answer the original question, your hub set is too tight. Take it back and have them assemble the hub set per the FSM. Quote Link to comment Share on other sites More sharing options...
pete280z Posted November 30, 2006 Author Share Posted November 30, 2006 I think jmortenson may be on to something. The hubs spun much more freely before I pulled the flanges down. After the flanges were installed it was tight. Now the the lock nuts are on it's worse. I don't think it's binding because the torque required to turn both hubs is constant. There is no catch. johnc - thank you for mentioning the fish scale. That is something I can visualize. So when the FSM says: Wheel bearing preload: 4.5 kg-cm (3.9 in-lb) At the hub bolt 790 gr (27.9 oz) or less Rear axle shaft end play: 0 to 0.15 mm (0 to 0.0059 in) you're adjusting until the shaft play is within spec and the hub will turn with the scale showing less than 27.9? I'll pull the flanges off tonight and see if the grease seals will go in any more. There's 0.0 chance of that "machine shop" touching my car again. No big deal if it's just the grease seal. If it's something else I'll spring for a different shop. Quote Link to comment Share on other sites More sharing options...
pete280z Posted November 30, 2006 Author Share Posted November 30, 2006 If they did pack everything full of grease it could blow that seal out the first time it gets hot. Grease expands and if there's too much it will build pressure. Hope that's not the case. I'm adding that to the list of things to check tonight. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted November 30, 2006 Share Posted November 30, 2006 If they used that much grease I doubt they missed this, but there should be some grease on the seal where it hits the axle too. No grease there would cause more stiction. Quote Link to comment Share on other sites More sharing options...
pete280z Posted November 30, 2006 Author Share Posted November 30, 2006 Heh. I actually had to clean some grease from the splines and threads to I could see what I was doing. I'm not sure if they did that to hide the fact that they goofed the ends of a few of the splines though. Quote Link to comment Share on other sites More sharing options...
pete280z Posted December 1, 2006 Author Share Posted December 1, 2006 It was the grease seals. Once they were tapped in a little further I made sure the inside of the seal had plenty of grease and reassembled. With the lock nut torqued in place the hub spins much more freely. They didn't drive the seals in much at all, just flush with the housing. I pushed them the rest of the way. The shop argued with me about this and I let them think that they were right to get things rolling again. Thanks guys! Quote Link to comment Share on other sites More sharing options...
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