MGD72Monte Posted May 13, 2012 Share Posted May 13, 2012 Thought some of you might find this interesting and if I have it wrong, one of the experts pls correct me. When I got my Jegs Differential Installation Kit for my 8.2" 10 bolt I found it odd that the crush sleeve was quite different than the one I removed. The new one is on the left with the original on the right. I know the diff was opened at some point in the past, does any one know if the one on the right is OEM? I called Jegs and they told me the one on the left is a new design and the original is no longer available. Here is what the original one looks like installed. You can see the base of the sleeve is in contact with the inner race of the pinion head bearing and the top is in contact with the tail bearing. Below is the new one positioned on the pinion (not fully installed). As far as I can tell, it uses the taper on the pinion shaft to wedge itself when the pinion nut is torqued down, then deforms at the centre. The wall thickess is about half as thick as the original one so hopefully it will be easier to crush than the old one must have been. My concern would be if I have to take this off, possibly if I overtorque it, how easy would it be to remove and replace this type of crush sleeve. Curious to see if anyone has experience with this type of sleeve. Do you have to cut it off to remove? Quote Link to comment Share on other sites More sharing options...
Ian Posted May 13, 2012 Share Posted May 13, 2012 I have only seen the original type. You might want to check these out, you do not have to crush them. I used one like it in my 12 bolt when I had them put it together for me. That way I can take it apart if I need to change the seal or yoke. http://www.summitracing.com/parts/RAT-4111/ Quote Link to comment Share on other sites More sharing options...
Mike 57 Posted May 14, 2012 Share Posted May 14, 2012 I would not use that crush washer! It is not correct for your application, it needs a a shoulder to stop on. If you try to crush it I am afraid it will be forced on the taper and you will have a heck of a time getting it off. Quote Link to comment Share on other sites More sharing options...
Wiham Posted May 14, 2012 Share Posted May 14, 2012 I think this may be the part you're looking for. Crush Sleeve Quote Link to comment Share on other sites More sharing options...
MGD72Monte Posted May 14, 2012 Author Share Posted May 14, 2012 I would not use that crush washer! It is not correct for your application, it needs a a shoulder to stop on. If you try to crush it I am afraid it will be forced on the taper and you will have a heck of a time getting it off. Thanks Mike, I think I am going to call Jegs again and ask for more explanation on how this part is meant to fit and what happens if you need to take it off. It would seem odd that their kit, designed for this specific differential would not have the right crush sleeve. Originally Posted By: Wiham I think this may be the part you're looking for. Crush Sleeve Sam, that would be the one, nice to know they still make it, very good to know if I don't get a good answer on how the new one is supposed to work. Quote Link to comment Share on other sites More sharing options...
Wiham Posted May 14, 2012 Share Posted May 14, 2012 I noticed the smaller style one that matches your photo on Summit as well, the listing states it's application is for aftermarket ring and pinion gear only, while the one I listed states it is for OEM only. I presume yours to be OEM style. Quote Link to comment Share on other sites More sharing options...
footballubet Posted May 14, 2012 Share Posted May 14, 2012 Definitely the wrong crush washer. The idea behind it is to preload the bearings. With that design it would not. I used the same style that Ian did. Quote Link to comment Share on other sites More sharing options...
geartech Posted May 14, 2012 Share Posted May 14, 2012 Yeah, I wouldn't use that either, if that is the 'right one', that would not set a dependable preload. That looks like a BOP 8.2 crush sleeve. You should be able to get the right one from Randy's Ring and Pinion or the type that someone pointed out for changing the preload to shims instead of a crush sleeve... Quote Link to comment Share on other sites More sharing options...
Mike 57 Posted May 15, 2012 Share Posted May 15, 2012 Jegs has the correct crush washer, link as some one stated it is for the OE gear the one you have is for a aftermarket gear. Quote Link to comment Share on other sites More sharing options...
MGD72Monte Posted May 15, 2012 Author Share Posted May 15, 2012 I noticed the smaller style one that matches your photo on Summit as well, the listing states it's application is for aftermarket ring and pinion gear only, while the one I listed states it is for OEM only. I presume yours to be OEM style. Originally Posted By: Mike 57 Jegs has the correct crush washer, link as some one stated it is for the OE gear the one you have is for a aftermarket gear. You guys are right, as usual. Thanks for steering me right. Whoever I was talking to the first time I called Jegs was not knowledgeable on the different sleeves when he told me the OE one was discontinued while they still carry it . I had a similar experience when I called today, the guy admited he didn't know and asked me to call back when the differential expert got back. I did and finally was told that it was not the right one for my application. I guess they figure if you order the kit, you are using an aftermarket gear set. For those who might be curious, here is a pick of an aftermarket Pinion and there is a ridge machined into the shaft. Presumably the short crush sleeves rest on that ridge, so it does not have to go all the way down to the head bearing. Definetly educational, wish it would be specified in the kit though or even in the catalogue so you know you have to order a different sleeve separately at the time. I must be the only clueless guy ordering this kit . If only I could cash in on all my ignorance . Anyway, thanks again, now on to my next problem. I'm still trying to figure out how I'm going to check for bearing preload (12 - 15 in.lbs) without having to buy a $250 dial type in.lbs torque wrench . Ideas welcome. Quote Link to comment Share on other sites More sharing options...
footballubet Posted May 15, 2012 Share Posted May 15, 2012 Is there an Advanced Auto or Auto Zone near you? They may have one to rent for free. Or check at any industrial rental company, they may have one. If you are using new bearings...the torque is 20-25 in. lbs. Quote Link to comment Share on other sites More sharing options...
MGD72Monte Posted May 16, 2012 Author Share Posted May 16, 2012 Scott, I'll check the local rental places, but I'm not holding out much hope as I have already checked out the main tool rental place up here. 20-25 in.lbs is a spec I've heard quoted a lot but the only actual ref I found (supplied by Mike (geartech)) linky says 12-15 in.lbs for GM 8.2" ring gear with new bearings. Is there another spec source I should be looking at? Thanks Quote Link to comment Share on other sites More sharing options...
Wiham Posted May 16, 2012 Share Posted May 16, 2012 Isn't the 12-15 in.lbs the actual preload for the bearing, and the additional 8-10 in.lbs (to get 20-25 in.lbs) the needed pressure to crush the sleeve prior to preload being set? Quote Link to comment Share on other sites More sharing options...
MGD72Monte Posted May 16, 2012 Author Share Posted May 16, 2012 Isn't the 12-15 in.lbs the actual preload for the bearing, and the additional 8-10 in.lbs (to get 20-25 in.lbs) the needed pressure to crush the sleeve prior to preload being set? As I understand it, you need 200 to 400 ft.lbs to crush the sleeve and get to the comparatively small preload amount. Quote Link to comment Share on other sites More sharing options...
Wiham Posted May 16, 2012 Share Posted May 16, 2012 Pure guess work on my end, I've never rebuilt a differential. Friend did in high school, but he started the post rebuild party to early and set the ring in wrong, tore it all to he**. Quote Link to comment Share on other sites More sharing options...
footballubet Posted May 16, 2012 Share Posted May 16, 2012 All the diffs I've rebuilt (and quite a few as we used to be a Jeep dealer) new bearings in the 20-25 in. lbs. range and used 10-15 in. lbs. It will loosen up with new bearings as they smooth out and seat properly. Quote Link to comment Share on other sites More sharing options...
MGD72Monte Posted May 17, 2012 Author Share Posted May 17, 2012 All the diffs I've rebuilt (and quite a few as we used to be a Jeep dealer) new bearings in the 20-25 in. lbs. range and used 10-15 in. lbs. It will loosen up with new bearings as they smooth out and seat properly. Scott, I'm not sure I understand what you are saying about the bearing rolling torque you use. Sorry if I sound dumb but I've read the first sentence a couple of times and can't tell. Are you saying that the bearings were 20-25 in.lbs type bearings but you torqued them to 10-15? Quote Link to comment Share on other sites More sharing options...
footballubet Posted May 17, 2012 Share Posted May 17, 2012 20-25 in. lbs. for new bearings is what you want to set it at. Disregard the other torque spec as I know you replaced the bearings. Sorry if I confused you. Quote Link to comment Share on other sites More sharing options...
Clever Idiot Posted May 17, 2012 Share Posted May 17, 2012 Well, after going over this entire thread, I've come to the conclusion that I should probably find a shop to do mine. The mag articles point out a few things, but I don't recall them ever getting into this much detail about what's needed! I thought I may be able to do it myself with the right instructional material, and now I'm just worried I'll miss something and end up grenading it. Unless, of course, somebody feels like a road trip to pick up a case of beer or two at some point... Quote Link to comment Share on other sites More sharing options...
footballubet Posted May 18, 2012 Share Posted May 18, 2012 Well, after going over this entire thread, I've come to the conclusion that I should probably find a shop to do mine. The mag articles point out a few things, but I don't recall them ever getting into this much detail about what's needed! I thought I may be able to do it myself with the right instructional material, and now I'm just worried I'll miss something and end up grenading it. Unless, of course, somebody feels like a road trip to pick up a case of beer or two at some point... I can help you through it when the time comes. Just send that case of beer. Quote Link to comment Share on other sites More sharing options...
Ian Posted May 18, 2012 Share Posted May 18, 2012 DJ if the guy that was building hot rods in the shop in front of the BMR shop is still there he has a guy that is real good. He did mine and it is working great. Quote Link to comment Share on other sites More sharing options...
MGD72Monte Posted May 18, 2012 Author Share Posted May 18, 2012 20-25 in. lbs. for new bearings is what you want to set it at. Disregard the other torque spec as I know you replaced the bearings. Sorry if I confused you. Thanks Scott, clarifies what you meant, I'm just having trouble figuring why there are so many different torque specs out there. The reference I found for the GM 8.2" 10 bolt from Yukon Gear and Axle lists 12-15in.lbs for new bearings and 6-7in.lbs for used bearings even for the 12 bolt it only gets to 14-19in.lbs. My Haynes lists 15-30 for new and 5-10 for used, but it is confusing as to whether they are referring to B and O type axles which mine is not, no specs for anything else????? The Jegs Diff kit I got came with no specs at all. I went to a local tranny shop and the guy says he checks it by feel so maybe it doesn't really matter?! The 20-25 you use is in the middle. When I rebuilt my engine I found a great book dealing specifically with the SB Chevy with all the torques, I know there is a book specifically for the TH350 transmission, what is missing is a GM differential book or some listing of official specs in some GM manual. Did the factories burn all their data? I definetly don't trust any of the shops around my area to steer me right. I'll probably go with your recommendation because it is in the middle, but I'm almost ready to resign myself to the fact that this thing will blow up on me no matter what. I guess that's the only way I'll learn I should have gone to a mechanics school... argh. Originally Posted By: MCBeast Well, after going over this entire thread, I've come to the conclusion that I should probably find a shop to do mine. The mag articles point out a few things, but I don't recall them ever getting into this much detail about what's needed! I thought I may be able to do it myself with the right instructional material, and now I'm just worried I'll miss something and end up grenading it. Unless, of course, somebody feels like a road trip to pick up a case of beer or two at some point... I have a pretty good book but it does not have application specific specs. I would not have thought finding simple torque specs to be so confusing. For now and until I get further along, the only help I will be able to give you is finishing that case of beer! Quote Link to comment Share on other sites More sharing options...
geartech Posted May 19, 2012 Share Posted May 19, 2012 You are not going to have any problems with new bearings/new crush sleeve and 20-25 in/lbs.... The thing is, its not an exact thing to begin with. Once you break in that rearend you can't say it will be 20 or 15 or 10 in lbs. Tapered bearings just have to have a slight preload and it goes without saying that a gearset is picky enough that it can't have any play in where the pinion could move. To compare, when you go to put in the carrier, you will be putting shims in the sides where the (tapered) bearings are. These are the shims you use to adjust backlash (and preload on these bearings). You will have to have preload here as well, but there is no way to measure it. You just have to be sure the shims go in with some force to put preload on the bearings. How much force is not really describable, experience will give you that. They have to be put in with some force and the carrier should have to be pried out if/when you remove it. No way to measure the rotational torque there. Its good you are concerned you are doing it right, that's the only way you'll be successful with a rearend setup. But I think you're on the right track -use 20 lbs with new parts and it will be fine. Quote Link to comment Share on other sites More sharing options...
MGD72Monte Posted May 20, 2012 Author Share Posted May 20, 2012 Thanks Mike, appreciate the words of wisdom. It gives me hope that this could actually turn out, I'm still looking for an affordable dial type torque wrench that will read that low. Quote Link to comment Share on other sites More sharing options...
footballubet Posted May 20, 2012 Share Posted May 20, 2012 Here is a beam type that will work just as well. You may need to pick up an adapter or two to fit your socket drive. Quote Link to comment Share on other sites More sharing options...
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