rudypoochris Posted February 27, 2008 Share Posted February 27, 2008 I had my R200 rebuilt awhile ago and unfortunately the front pinion bearing seems to be NLA. The dimensions on it are: 73mm OD 28mm ID 16mm Width From this thread: http://forums.hybridz.org/showthread.php?t=112388&highlight=r200+front+pinion+bearing In any case, thinking over this I feel like I should have the front pinion bearing replaced as well since it seems that this bearing goes "sandy" more often then not. One of the posters in the above thread mentioned that an SKF 62/28 common bearing could be used with a sleeve to up the diameter from 58mm to 73mm. What are peoples initial thoughts on this idea? Does this bearing see axial load? If so, in what direction? What would one make the sleeve out of? Lastly, what would be an acceptable ID to make this interference fit snug and "doable" with simple freezing and boiling of components? My initial thoughts are that axial loading would be minimal if any. If necessary a lip could be made on the sleeve, but that only covers loading in one direction. I think with the lip towards the rear of the case is the most feasible (I haven't looked inside yet, but I think there is a seal that might interfere towards the front). As for sleeve material, I would think 4130 or 4340 steel would be fine. Maybe even 7075-T6 Aluminum. I have no clue what ID would make an acceptable clearance fit w/o using a press, or maybe a press should be used. Possibly 57.5mm? Thanks guys! Quote Link to comment Share on other sites More sharing options...
rudypoochris Posted February 27, 2008 Author Share Posted February 27, 2008 The spacer is an interesting idea. If you wanted to all you'd have to do is pull the pinion nut and pull the seal and that bearing is right there. If you didn't care about trying to save it I'd imagine some creative slide hammering would get it out. Interesting. Do you know if this will effect the backlash and all of the tolerances in the differential (requiring adjustment)? Or is this bearing really just there to support some radial loading? Do you think there would be room or necessity for a lip on the rear side of the sleeve? Thanks! -------------- Here is my initial drawing, lipped and chamfered .5mm for ease of installation: OD: 73.0mm ID: 57.5mm Width: 20.0mm Lip ID: 54.0mm Lip Depth: 4.0mm Quote Link to comment Share on other sites More sharing options...
JMortensen Posted February 27, 2008 Share Posted February 27, 2008 The pinion depth and preload are set with shims that are further down on the shaft. You wouldn't screw anything up by pulling the bearing and putting everything back together. The only other thing in there is a big spacer, but if it were to come out you could just stick it right back in and it wouldn't affect any tolerances. I would think you wouldn't want to use aluminum for the spacer because it expands and contracts at a different rate than the cast iron diff housing would. Whether steel would work, I don't know. I'm not a big fan of diff coolers, I think they're mostly overkill for your average Z owner, but bjhines had a pretty good idea with his cooler that might solve that bearing issue. He had the pump dump the cool oil into the passage that leads to that bearing. I think the problem is it's so far away from the sump and if you're going uphill there isn't likely to be very much oil getting to it. Quote Link to comment Share on other sites More sharing options...
rudypoochris Posted February 27, 2008 Author Share Posted February 27, 2008 I could use iron... I think the lip is not necessary. Quote Link to comment Share on other sites More sharing options...
jbk240z Posted February 27, 2008 Share Posted February 27, 2008 I found this bearing on napaonline, typed in the application for a '78 280Z and got this result. Hopefully this helps you. Good luck. http://www.napaonline.com/MasterPages/NOLMaster.aspx?PageId=470&LineCode=BRG&PartNumber=BR32307&Description=Pinion+Bearing+-+Rear+Axle Quote Link to comment Share on other sites More sharing options...
rudypoochris Posted February 27, 2008 Author Share Posted February 27, 2008 Thanks, but that is not the correct bearing. There is something like 3 bearings for the pinion shaft. 2 of them are still available and clearly take axial loads because they are conical. The third is the one in question which is a deep groove ball type and hopefully does not take axial loads. It is not available though. EDIT... The steel pretty much matches the expansion of the irons I have seen. The aluminum has twice the expansion rate. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted February 27, 2008 Share Posted February 27, 2008 Yeah, that ball bearing shouldn't be taking any thrust loads. It just keeps the pinion centered in the housing. I don't know why they chose to use a diff with such a long pinion shaft, I suppose it must have been to tie into the front bushings for the rear control arms, regardless it's less than desireable to do it that way. Quote Link to comment Share on other sites More sharing options...
johnc Posted February 27, 2008 Share Posted February 27, 2008 If someone has the bearing number I'm sure I can find it through the bearing houses I use. I just had a R200 rebuilt for a customer 5 months ago and Unitrax had no trouble finding ALL the bearings inside the unit. Quote Link to comment Share on other sites More sharing options...
rudypoochris Posted February 27, 2008 Author Share Posted February 27, 2008 If someone has the bearing number I'm sure I can find it through the bearing houses I use. I just had a R200 rebuilt for a customer 5 months ago and Unitrax had no trouble finding ALL the bearings inside the unit. Here you go: Nissan PN: 38335-N3100 Koyo PN: 83601ASH4C3 (83601A for short) Thanks! Quote Link to comment Share on other sites More sharing options...
zcarnut Posted February 27, 2008 Share Posted February 27, 2008 Having studied the spacer concept for the R200 front bearing previously, I think the spacer should be a “tight†interference fit (or shrink fit) onto the bearing but it should be a “light†interference fit when the bearing/spacer combination is pressed into the R200 housing (pinion opening). This will ensure that the spacer will not move after installation and yet will allow easy removal. Your figure of 57.5mm for the inside diameter (ID) of the spacer is way too small. Typically, a “tight†interference fit requires a mismatch of .002 to .003 inches. Using 57.5mm your interference is 0.5mm or .0197inches. You would likely break the parts trying to press them together with this much mismatch. I would start with a spacer having an ID of 57.925mm which is 58mm less .003â€. The outside diameter (OD) of the spacer with the bearing installed should be .0005 to .0002 larger than the ID of the R200 housing (73mm) for a “light†interference fit. This would imply that the OD of the spacer should be around 73.01mm after machining, however, the process of pressing the bearing into the spacer (because it is an interference fit) will actually increase the OD of the spacer. Exactly how much depends on several factors, but it will be almost the amount of the interference (.003). So, start with a spacer OD of 73mm less .003†*.8 plus .0004†or 79.95mm. Quote Link to comment Share on other sites More sharing options...
rudypoochris Posted February 27, 2008 Author Share Posted February 27, 2008 Thanks for the help! I have spoken to the Koyo rep he says: I don’t recommend a sleeve on this application as the vibration that is seen in a differential is likely to cause the sleeve to move and a sleeve that large is questionable in any application and if the sleeve moves it could result in catastrophic failure of the differential Also the SH4 treatment is highly recommended in a differential as there is often shavings mixed in the oil I need to look at the differential a bit more to see if the sleeve moving is an actual issue. As for the SH4 treatment (he let me know it is a carbon nitrating treatment to protect the rings from metal shavings), I don't know. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted February 28, 2008 Share Posted February 28, 2008 I would think it would be easy enough to leave a lip on the sleeve so that it can't slide deeper into the diff. It won't slide the other way because of the seal. Quote Link to comment Share on other sites More sharing options...
rudypoochris Posted February 28, 2008 Author Share Posted February 28, 2008 I would think it would be easy enough to leave a lip on the sleeve so that it can't slide deeper into the diff. It won't slide the other way because of the seal. Would that require a thinner bearing, I think it would. There is a 12mm version... Quote Link to comment Share on other sites More sharing options...
JMortensen Posted February 28, 2008 Share Posted February 28, 2008 Would that require a thinner bearing, I think it would. There is a 12mm version... No, the way I figure it you just a lip on one side. The bearing won't slide because it is pinned between the spacer and the pinion nut. The spacer can't move out, so you'd only need a small lip on the outer edge to prevent it sliding in. Quote Link to comment Share on other sites More sharing options...
blueovalz Posted February 28, 2008 Share Posted February 28, 2008 I'm going to raise the issue of thrust (axial) force here again. My thoughts are the helical cut gears, or any gear cut other than straight would impose some kind of thrust on both gears. This is true with transmissions or any angle-cut gear. Would not the ring/pinion cut not also apply? Quote Link to comment Share on other sites More sharing options...
JMortensen Posted February 28, 2008 Share Posted February 28, 2008 I'm going to raise the issue of thrust (axial) force here again. My thoughts are the helical cut gears, or any gear cut other than straight would impose some kind of thrust on both gears. This is true with transmissions or any angle-cut gear. Would not the ring/pinion cut not also apply? All of the thrust forces are taken by the two large cone/cup bearings. The bearing in question is a pilot bearing. Quote Link to comment Share on other sites More sharing options...
rudypoochris Posted February 28, 2008 Author Share Posted February 28, 2008 I have been using the incorrect terminology I believe, the bearing is actually the front PILOT bearing. If an admin could rectify the title that would be peachy! No, the way I figure it you just a lip on one side. The bearing won't slide because it is pinned between the spacer and the pinion nut. The spacer can't move out, so you'd only need a small lip on the outer edge to prevent it sliding in. If I did not strive for a 16mm width though, would the differential need to be re-shimmed? I would like this to be as painless for myself and others as possible seeing as I just spent $200 to have the unit rebuilt. Heh. Just to make sure I am understanding this right... Image below: So. The red marks the bearing in question. The blue shows the axial force traveling through the pinion to the front of the differential. This force terminates at the outer race of the rear conical bearing. The green shows the axial force going towards the rear of the vehicle, this is the one that matters to us. I appears that the force is indeed transmitted straight through the inner race of the bearing in question. Thus, there should be absolutely no axial loading. If one were to add a lip which probably is not necessary due to the "pinion bearing spacer" pushing against the "companion flange", I would guess the orange (front) side in picture 2, would be the place to put it. What is in the orange space? The oil seal? Is there room for 2-4mm more out race thickness, can the seal be modified? The sleeve inherently cannot move towards the front of the differential, due to whatever is in the orange space (oil seal?), unfortunately it appears the path out the rear of the differential is open space and thus it could in theory slide that direction, a lip on the front would prevent this. In either case, a good interference fit SHOULD hold it with out a lip, but I rather not be the one to find out. After repeated vibrations and loading, it seems hardly a guarantee to me. Maybe lips on both sides with a weld down the center then ground down on the lathe may work, but that would be a pretty decent amount of work. BTW if I am misunderstanding anything here in any way, let me know! Also, apologies for the excessively large pictures, I felt it necessary to size them this large to understand them properly. EDIT: Here is the idea I have so far... Two halves to the sleeve. Each one 10mm total thickness. 57.925mm ID, 72.975mm OD, 54mm lip diameter, 2mm wide lip, .5mm chamfer. That would allow for the center of the two halves to welded onto the bearing. The bearing would be the type 62/28 discussed earlier. I believe SKF might mike a "No Wear" version which can withstand low lube environments. It might be better just to use a shielded bearing though which might, maybe, I don't know??? Keep metal shavings off the races. Quote Link to comment Share on other sites More sharing options...
rudypoochris Posted February 28, 2008 Author Share Posted February 28, 2008 Another option would be to run the bearing outer race in the lathe and remove .003" of material from the center. Freeze the bearing, boil the ring, attempt to mate them. Allows to retain 16mm width. Downside, not as strong, requires great precision, difficult. Quote Link to comment Share on other sites More sharing options...
jbk240z Posted February 28, 2008 Share Posted February 28, 2008 Some guy told me today that a '90 Infiniti M30 uses the same bearing in the diff. I don't know if this is true, if so, might be easier to find. Good luck. Quote Link to comment Share on other sites More sharing options...
jbk240z Posted February 28, 2008 Share Posted February 28, 2008 Some guy told me today that a '90 Infiniti M30 uses the same bearing in the diff. I don't know if this is true, if so, might be easier to find. Good luck. Quote Link to comment Share on other sites More sharing options...
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