MGD72Monte Posted January 26, 2012 Share Posted January 26, 2012 Any suggestions on a non-destructive way of removing the pinion bearing? As I understand it, when you install a new set of gears you may have to make more than one pinion shim adjustment to adjust the pinion mounting distance. This requires removing the pinion bearing to access the shim every time. I can't imagine you are supposed to destroy a set of new bearings at every adjustment. The book I have shows a clamshell type of tool, but I have not found it amongst the local loan a tool options. How is everyone dealing with this task? Thanks Quote Link to comment Share on other sites More sharing options...
geartech Posted January 26, 2012 Share Posted January 26, 2012 Yes, sometimes you have to make a pinion shim adjustment but not always. I always start with the one that was in there. I'd say about 3/4 of the time you don't have to change it. I have a hydraulic press and bearing splitter to pull the pinion bearing off without damage. I think this might be the type of tool you are referring to... Bearing Puller They work well but are a bit pricey. you put the right size collars around the bearings and body of the tool, and use an impact to pull the bearing off. A shop I used to work at had one and it was slick, but I went the way of owning a press as I can use it for other things. Depending on your tools and the room between the pinion head and the bearing cage, you can ruin a new bearing when you press it off, sometimes it happens. As far as knowing if you need to change that shim, there are a few different situations... --You are putting in a used gearset or a new on that has no markings. You have reassemble everything and check the pattern to know what to do. Take it all back apart and adjust the shim, and repeat...very time consuming, but sometimes has to be done. If you are putting together something that's already been taken apart, or otherwise don't know shim to put inthere at all, there is a list of 'starting point' shims that I have out in the garage if you need it, like if I remember right, a 12 bolt should be .030" shim, at least that will get you close as a starting point. --You are putting in a GM gearset and it is marked +1 or -2 or whatever. This means you can compare that marking to yours if yours is original. This refers to the amount that is off from a GM standard when they checked it. So for example, if your old pinion is marked +1 and your shim was .031", and your new (or used) gearset is marked +3, you'll need a .033" shim. -- You are putting in a Richmond gearset (for example) that has the "pinion depth" marked on the head of the pinion. Like 2.657 or something like that. That is the distance between the centerline of the carrier to the head of the pinion, This can only be checked with a special tool, a type of depth micrometer. If you have it, you can put the pinion in (with the bearing pressed on and a starting shim in there), check the depth and if its off, you only have to press of the bearing once, as with the reading, you'll know how much it needs to change. whew, sorry for the long reply. I can explain more if you want, I've done alot of rear axles. Quote Link to comment Share on other sites More sharing options...
cny first gen 71 Posted January 26, 2012 Share Posted January 26, 2012 Actually that was pretty short Mike as setting up a rear end is very time consuming. I havent done one in years and only stock replacement never a high performance. My suggestion would be (just to be sure) find someone that can set it up for you, there are so many ways to mess it up. The mesurements are very precise and if you get it wrong it will destroy all your hard work. just a suggestion. Quote Link to comment Share on other sites More sharing options...
geartech Posted January 26, 2012 Share Posted January 26, 2012 It was just a longer reply than I set out to type, I guess. True that you have know what you're getting into, and the wherewithal to make sure its done right. Its expensive generally even to do it yourself... Quote Link to comment Share on other sites More sharing options...
MGD72Monte Posted January 28, 2012 Author Share Posted January 28, 2012 Mike, That special tool looks close to the one in my book and would be more than the price of the overhaul so I'm thinking I'm going to pass. I do have access to a press though, I'll try to see if I can get a bearing splitter to try my luck. My situation is an overhaul on a stock 10 bolt 2.73, 8.2 ring gear. I have finished emptying the diff case and will be getting it sandblasted so I can paint it. Then new seals, bearings, axles but re-using everything else so hopefully no shim change? I really appreciate all the info you took the time to put down. Steve, it would be nice to have someone help me set it up like you suggest. Those people seem to be in short supply. I don't know anyone who has the knowledge around here and is willing to take the time to help me so I guess I'll have to rely on books and help I get from here. I'll keep you guys posted and I'll be back with more stupid questions . Quote Link to comment Share on other sites More sharing options...
cny first gen 71 Posted January 28, 2012 Share Posted January 28, 2012 If your keeping the same ring and pinion and carrier hopefully you kept track which side the side shims came from and should go back in the same way. you should change the collapsable spacer and retorque the new one to factory spects. That sets the pre loads on the bearings hopefully everything else remains the same. Quote Link to comment Share on other sites More sharing options...
geartech Posted January 28, 2012 Share Posted January 28, 2012 Yes if you're reusing the same gears and carrier, then you should not need to change the shims. Just be sure to get the new pinion bearing races all the way into the housing, you can check with a feeler gauge to make sure they're seated. No questions are stupid, I have the benefit of being a mechanic for 10 years and then changed careers, but people sought me out to do differentials after that, to the point I did it as a side business for a while("geartech"), and basically got burnt out on it. Here is something for you to read and look around on this site too. http://www.ringpinion.com/Content/HowTo/...nstructions.pdf Quote Link to comment Share on other sites More sharing options...
MGD72Monte Posted January 29, 2012 Author Share Posted January 29, 2012 Steve, yes I've got the carrier shims and bearing caps identified and the kit I'm planning to get JEGS Kit has a new collapsible spacer. The axles I'm hoping to pick up are JEGS Axles Mike, thanks for the useful link, I was actually looking for the torque specs so this great. Thanks for the tip about the races. I wish I had your experience at this. More to come. Quote Link to comment Share on other sites More sharing options...
MGD72Monte Posted March 11, 2012 Author Share Posted March 11, 2012 Finally removed the pinion bearing today using a bearing spreader and a press at the auto hobby shop. It came out no problem, in great shape because you can get the spreader behind the inner race. Next is removing the carrier bearings. I don't see how I can get behind the inner race, the closest I'm going to get is behind the cage. Can I pull on the cage to get these out. Unlike the pinion, I don't care about damaging the carrier bearings, but I don't want to start grinding these out. Any opinions. Thanks Quote Link to comment Share on other sites More sharing options...
alex's72fgmc Posted March 11, 2012 Share Posted March 11, 2012 fyi, one thing i learned was to take a cylinder hone and hone out a new bearing to use for shim testing "just enough to slide on fairly easily but not loose then when you have the right shim in put on the new unmodified bearing. Quote Link to comment Share on other sites More sharing options...
alex's72fgmc Posted March 11, 2012 Share Posted March 11, 2012 on the carrier bearings use tin snips to cut the cage off and then use the bearing splitter to pull the rest of the bearing off utilizing a peice of 1/4 in plate steel to sit on the snout of the carrier. another option is to use a axle bearing puller on the bearing and slide hammer it off. Quote Link to comment Share on other sites More sharing options...
Mo's70MCs Posted March 11, 2012 Share Posted March 11, 2012 here's a cheap method.. if you don't have a press or a puller, though there are others methods but those are best left for dire straits. Quote Link to comment Share on other sites More sharing options...
Winston Wolf Posted March 11, 2012 Share Posted March 11, 2012 Just cut the carrier bearings off with a dremel. Quote Link to comment Share on other sites More sharing options...
geartech Posted March 12, 2012 Share Posted March 12, 2012 The best way is to use a press and bearing splitter, but often the carrier is too large for the throat of the press. I had to modify mine to be wider to accomodate most(not all) carriers. Rod's method above is a good one. Cutting it off with a cutoff tool is difficult, without nicking the carrier, but it can be done. One thing to offer that might sound silly, but wear safety glasses. When that splitter, or whatever method you use, is pulling on the race, it is likely pulling on the cage too, or at least putting pressure on it. This transfers some of the force to the rollers, which then push on the outer lip of the race. That outer lip can then break, or a small piece of it, and that piece will undoubtedly come straight at you. Just the voice of experience talking... Quote Link to comment Share on other sites More sharing options...
MGD72Monte Posted March 12, 2012 Author Share Posted March 12, 2012 Thanks guys, I'm not keen at taking the Dremel to this as I want to save the race to help me press on the new bearing. I'm still not sure how I can grab the back of the bearing race with the bearing spreader, from what I can tell it will simply be grabbing the race and rollers, but I'm going to head back to the auto hobby shop on Monday night to see what I can do. Quote Link to comment Share on other sites More sharing options...
MGD72Monte Posted March 25, 2012 Author Share Posted March 25, 2012 Finally got to tackling the carrier bearings. To answer my own question above, You can pull on the carrier it is solid but if you don't feel comfortable with that you could cut the carrier with tin snips, remove the rollers and pull on the outer lip of the race. One side came out like butter using a puller and a bearing splitter. In fact the inner race was spinning on the carrier. The other side unfortunately was a no go, it is in so tight that I bent one of the bolts from my cheap puller. I had resolved to cut it off with a Dremel and started but stopped as I'm paranoid at nicking the carrier. For those that have done this, is there a technique that can minimize the possibility of damage? Will I see something obvious as I cut through the race and before I hit the carrier? Quote Link to comment Share on other sites More sharing options...
Leghome Posted March 26, 2012 Share Posted March 26, 2012 What about cutting it with the dremel close but not thru and then using the puller? Quote Link to comment Share on other sites More sharing options...
footballubet Posted March 26, 2012 Share Posted March 26, 2012 Cut into the race as far as you feel comfortable then use a chisel or air hammer with a chisel bit end and crack the race. You can then tap it off the carrier. You said the other side bearing race had spun? If it spun you better check to see how badly it has chewed the carrier surface. You don't want the inner race spinning on the carrier. If you can push the bearing on by hand that is no good. I've had them where they spun and still had a tight fit. In that case I've taken a center punch chisel and peened the whole way around the surface of the carrier then installed the bearing using the Loctite bearing adhesive on the way back together. Otherwise you'll need to replace the carrier. Quote Link to comment Share on other sites More sharing options...
MGD72Monte Posted March 26, 2012 Author Share Posted March 26, 2012 What about cutting it with the dremel close but not thru and then using the puller? Thanks, I was thinking the same thing. I won't have access to the bearing spliter until later this week. Originally Posted By: footballubet Cut into the race as far as you feel comfortable then use a chisel or air hammer with a chisel bit end and crack the race. You can then tap it off the carrier. You said the other side bearing race had spun? If it spun you better check to see how badly it has chewed the carrier surface. You don't want the inner race spinning on the carrier. If you can push the bearing on by hand that is no good. I've had them where they spun and still had a tight fit. In that case I've taken a center punch chisel and peened the whole way around the surface of the carrier then installed the bearing using the Loctite bearing adhesive on the way back together. Otherwise you'll need to replace the carrier. Did not think of using the air chisel on this, I might give that a shot. As for the other side I could spin it slowly by hand but still needed a puller to remove. I did not notice any spinning related damage but I'll have a closer look at both the carrier surface and the bearing inner race. I sure hope I don't have to trash the carrier . Quote Link to comment Share on other sites More sharing options...
Winston Wolf Posted March 27, 2012 Share Posted March 27, 2012 I wouldn't worry about knicking the carrier... If you do, sand or lightly file the knick down and move on. Quote Link to comment Share on other sites More sharing options...
MGD72Monte Posted April 1, 2012 Author Share Posted April 1, 2012 Well I finally removed both bearings from the carrier. As per above, the first one came out easy using a puller and bearing splitter. As the bearing inner race could be turned by hand it did score the shaft on that side as per the following picks. Here is another shot of it. does anyone know if the ridge shown by the arrow is normal or is that damage from the race spinning. For the other side, the puller was not strong enough, I used a cut off tool until I was close to the carrier shaft then an air chisel as suggested by Scott and eventually a crack formed. After that I was able to drive the race off with the air chisel using the bearing race inner ridge. The shaft is noticeably smoother on this side. I'm going to blend out the dents. This shot shows the bearing race I cut off. The inside has a thin black gummy layer (shown by arrows). The same was on the shaft. Might be the reason it was so hard to remove. Not sure what it is. If it spun you better check to see how badly it has chewed the carrier surface. You don't want the inner race spinning on the carrier. If you can push the bearing on by hand that is no good. I've had them where they spun and still had a tight fit. In that case I've taken a center punch chisel and peened the whole way around the surface of the carrier then installed the bearing using the Loctite bearing adhesive on the way back together. Otherwise you'll need to replace the carrier. Based on seeing the actual pics, any further thoughts. I sure hope I can re-use this carrier in spite of the scoring on the one shaft. I tried to push the bearing in by hand on that side and I can't but I'm not sure how tight it will be with a new bearing when it is fully pressed in. There is a small ridge on the top. which may make it seem tight until it bottoms out. Quote Link to comment Share on other sites More sharing options...
alex's72fgmc Posted April 3, 2012 Share Posted April 3, 2012 this case i would say to but a posi unit and upgrade while your at it. it is not worth saving with that much damage. but if you want to save it take it to a good machine shop and have them build up the bearing area with weld "Ni-99 weld wire i believe" and then they will machine it back down to spec. plan on spending about 150-200 bucks. most likely it will be less but error on the high side in this case. Quote Link to comment Share on other sites More sharing options...
footballubet Posted April 3, 2012 Share Posted April 3, 2012 I agree with Alex. Find a machine shop to repair the damage. That looks a little too far gone to try to put back together that way. I've had a couple bearing surfaces spray welded and machined back to specs. Good as new. Quote Link to comment Share on other sites More sharing options...
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