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Service manual only states to install left shim, then it will be necessary to use shim driving tool to drive right side in. Is it this simple? I'm reading of other methods, case spreaders, etc. Service manual makes no such reference to such tools, service manual reads as if getting the right side shim in is no big deal. comments and suggestions please, thx!
The method I used was get a shim pack figured out so that the diff is fixed in the carrier with no lash. You should be able to get your shims in and out. They should be snug to tight, but not to tight where you would have to fight or struggle with them. Now when your make adjustments to move the carrier left or right, what ever shim your remove from one side you add to the other. This will keep everything snug and in place. You would be moving your carrier back and forth in an attempt to set the backlash. Once you are satisfied with the backlash you would pull the shim pack from each side and measure it. Now you will make a new shim pack .004 thicker and this should give you the proper preload on the carrier bearings. This is what I did to my truck over 130,000 miles ago and it is still smooth. The last shim to install will be the most difficult. You will probably have some thin shims and some thick ones all on the same side. Put all the thin ones in first and put the last one, a thick one in between other thick ones and it should go in no problem. This is generic information out of a repair manual for 98-99 trucks including S-10's which I think is the same as the camaro. You definitely want to have the exact info for your exact differential. The case spredder is something recommended for a DANA and other versions. It is not necessary or recommended for a 10 bolt.
This is what I use the 2 big C-clamps for, that you asked about earlier in one of your other posts on this matter.
Stack up your 2 shim packs to get your desired backlash (should ideally be around .008 - 010" or so) with the carrier fitting between them as tightly as you can reasonably get it. Slightly more (emphasis on slightly) is better than even a little bit too little: gears GROW when they heat up, and if you start out with too little, it will ALL go away under sustained heavy load, and I think we all know what will happen when 2 pieces of metal try to occupy the same volume. They should be built up with 2 .100" (thick) ones on each side, with a handful of thinner ones in between. Typical thicknesses on each side are .225" - .275", usually .240" - .260". Once that is accomplished, add .005" to each pack; set them into the housing; clamp the outer races onto the bearings with the C-clamps; tighten the C-clamps GENTLY until you can just barely get the carrier to drop down in between the now too-thick shim packs; and remove the C-clamps when it's as far in as it will go with them still on there. Then of course put on the caps. You might be able to get more than .005" of extra shim in there without having to use too much force. The more preload you can get, the better, up to the point that you damage the bearings trying to put them in.
DO NOT NOT NOT NOT NOT NOT attempt to put the extra shims for preload in after the carrier is already in!!! All you will accomplish that way is to wad them up.
Never heard of a "shim driving tool". Might be something the factory uses; rather than a stack of thin shims like we use out here in the real world, they use thick selective-fit one-piece cast iron ones. Might be something that would work with those. But there's no such thing for aftermarket ones.
A "case spreader" is the "book" method in the service world for virtually ALL non-"chunk" type rears. (i.e. other than the 9"; including GM 10- and 12-bolts) It's a bunch of angle iron, turnbuckles, press screws, and such as that, that you bolt onto the case somehow (details vary), and spread the case apart, making the hole the carrier fits in wider rather than compressing the bearings, to allow assembly. Then of course when you remove it the case goes back to applying preload. I've never had or used one in all the rears I've ever done.
Last edited by sofakingdom; Oct 15, 2019 at 07:13 PM.
Once I am absolutely sure of my left and right shim thicknesses (with preload added in) I make my own one-piece spacers. That way I (or anyone else) can never mess it up - with only 2 shims, only 1 way can be correct. And with such thick shims, it is easier to tap them in.
This is what I use the 2 big C-clamps for, that you asked about earlier in one of your other posts on this matter.
clamp the outer races onto the bearings with the C-clamps; tighten the C-clamps GENTLY until you can just barely get the carrier to drop down in between the now too-thick shim packs; and remove the C-clamps when it's as far in as it will go with them still on there
sorry, I can be a little slow sometimes. I am confused on how you are positioning the C-Clamp to accomplish this? Is it parallel with the axles? Or 90 degrees to them? what is the c-clamp attachment points - that is where I am confused?
Put the outer races on the bearings. Use the C-clamps to compress them on, on opposite sides, so they compress straight and evenly. Try to put the carrier in, and tighten the clamps in small increments until it will go in. Put it in as far as the clamps will let it go, remove them, and gently tap the races farther in until you can start the cap bolts, then let those finish pressing everything in.
The idea is to make the shims too thick to fit, so that there will be preload on the bearings. If there's no preload, the least wear on the bearings will make the carrier get loose in there. You gotta put some preload on them first to get them to go in.
Yes, somewhat. Exactly like that except different.
Use actual C-clamps, the kind that are the forged steel frame that looks like a "C" with the press screw. I don't think those wood ones will have enough nads, as well as, being made for spreading the load, but you'll need it fairly concentrated. You'll need 2; 180° apart on the bearings.
And of course, put the outer races on the bearings before the clamps, and press on them, not on the cones.
I like NoE's idea of making a one-piece shim but I lack the technology for that.
Last edited by sofakingdom; Oct 15, 2019 at 07:14 PM.
You don't need those clamps. You do not have one solid shim like someone mentioned that they prefer. You do have a stack of them though. Get everything in except your thickest shim, put the thickest shim in between the next two thickest shims and when it gets tight you will have to tap it in with a drift or something. It would be the exact same process as a shoehorn, hence the term shoehorn it in there. I can only assume you are doing this to save some cash and learn stuff. Don't discount the clamp method, I have not used it so I won't say it's wrong. It is just a different approach. Before you got getting things you may not need, try my suggestion.
I can only assume you are doing this to save some cash and learn stuff.
Not quite following what you mean? by using the clamps? I just want to install them using the easier method. sounds like your method could be pretty easy.
the tool the service manual recommends looks like this:
If you can "tap in" an aftermarket shim, it's too loose. If the shim packs are tight enough, there's NO WAY to "tap in" the required ones. They'll just wad up. If you're able to "tap in" more shims, then there's NOWHERE NEAR enough preload; really, more like none at all. Just because you did it "once" that way and it still works, doesn't mean it's "right". I personally knew someone who was skydiving one day, and their parachute failed to open, and they survived... does that mean I should get on all the skydiving message boards and tell people they don't need parachutes? After all, I have first-hand personal knowledge that "a guy" survived without one? It's what we refer to as "the curse of the small sample size". Just because YOU got lucky ONCE, does NOT automatically mean that EVERYBODY ELSE will get lucky the same way EVERY TIME, and you have The Magic Bullet for the procedure. I'm not calling you a liar, any more than I should be called a liar about the guy with the defective parachute; but that doesn't mean that it is a "plan" that should be followed by everybody.
I'm not sure how I can explain this any simpler, or what it is that's not clear yet. You've got a carrier; it has bearing inner races & cones pressed onto it. You put the outer races on and set it into the housing. You stack up shim packs on each side to get the backlash (play between the ring & pinion) that you want, making them as thick as they can possibly be during this process so that there's no end play in the bearings confounding your backlash setting. Once you establish that, you add at least .005", preferable more but probably not more than .010", to each shim pack; they are now too thick for the carrier to fit between them, but when preloaded equally, will hold the carrier in the correct spot that the backlash is what you want. You put the shim packs into the bearing saddles. You add the outer races to the carrier, then take the 2 C-clamps, and tighten them down on the edge of the outer races, 180° apart, to press them onto the cones. You tighten them GENTLY, in small increments, until the bearings are pressed together JUST ENOUGH that you can get the carrier and bearings to drop down in between the too-thick shim packs. You'll get to a point where the C-clamps hit the shims as it slides in; at that point, take them off. GENTLY tap the carrier the rest of the way in, at least far enough to where you can put on the caps and tighten them down to press it the rest of the way in.
I think once you attempt it, it will become obvious.
The tool in your picture would work EXACTLY the same way. I've never seen or heard of that but it's EXACTLY the same principle, just in a different shape. 2 of them would be required, along with a threaded rod or something to go through the holes, and something to hold the tabs at the top apart. You'd put the thing in that holds the tabs apart and tighten nuts on the threaded rod to press on the outer races, EXACTLY the same as you'd do with C-clamps.
[QUOTE=LiquidBlue;6335403]Not quite following what you mean? by using the clamps? I just want to install them using the easier method. sounds like your method could be pretty easy.
I was referring to the entire overhaul of the rear end. As far as that tool I don't know what that is. Looks like it would cup a thicker shim and distribute the load of tapping it in. I used a brass rod or drift and moved it from side to side. I was avoiding the center as to not collapse or distort it. The manual I referenced showed some type of slide tool or adjustable shim to determine the zero preload shim thickness. I took this to mean finding zero lash between the carrier assembly with bearings and races, the housing, and the shims. All the room is used up but it is not cram packed so tight that the bearing are bound up.
Ok, I'm sure I'll have more questions once I get there. last night I was on the floor wrestling with the old carrier bearings, managed to get one off, tried the 2nd and it was bending the bearing seperator. guess its better to bend than to break. was tired, doused it with wd40 and gave up before I hurt myself.
what do you make of Figure 25? I don't understand the starting thickness chart? how can starting point shim be 1/2 the thickness of what was removed? (here goes the entire manual for this section)
Last edited by LiquidBlue; Oct 17, 2019 at 10:23 AM.
think I see what it means, they are assuming you have production spacers in there, which are cast iron and very thick - which should be replaced. this part gets replaced with 2 parts, a spacer, and multiple shims. chart 25 is the starting point for the shims, which if added to the spacer, is close to the width of the single production part.
oh, btw, what the hell does "pre-load" mean anyway?
Those production spacers are what I referred to as the thick shims. Gravity is going to make the races want to spread because of the cone shape. They want you to get a feeler gauge in between the production spacers and the bearing race. You have to make sure the races are not spreading. They have to be seated on the bearings tight enough to center the assembly but not to tight to cause ANY resistance in the operation of the bearing. When you start adding resistance, making it harder to turn you would be adding preload. They have figured out what to add to get the desired preload. Zero preload makes assembly and disassembly for backlash adjustment less complex. You add the .004 shims during final assembly. When you set the preload on the pinion it is also upon final assembly. You measure it with a dial type inch pound torque wrench. If you were to set up the carrier in the housing without the pinion, you should in theory be able to measure the rotational force and adjust it to spec. The manual just recommends an alternate way of going about it. Now if you were to put you axle housing vertical. Put in your production spacers, first shim pack, bearing race, carrier with bearings installed, other race, production spacers. Gravity will help by seating the carrier in the race and compressing the shims and spacers under it. The weight of the other production spacers will help seat the top bearing race. The rest of the room has to be made up of shims. Start with something close. Pull out your spacers, put in your shim pack. Now use one of your production spacers as your feeler gauge and adjust your shim pack until you achieve the slight resistance mentioned in the manual. You should end up with zero preload at this point.
Last edited by 91ls1t56; Oct 18, 2019 at 08:53 AM.
Preload is compression applied to bearings even at no load.
It's the same thing you do to pinion bearings by tightening the nut past the point where all play is taken up, until it takes some certain amount of torque to spin the pinion. You do the same sort of things to wheel bearings. Note that applied properly, nothing gets "bound up".
ALL tapered roller bearings require this. Without it, they would develop play immediately as they wear, which in the case of a carrier, would add to the backlash, ALOT. Very bad.
The normal loads on those bearings can be several thousand pounds. They need to be preloaded with some appreciable fraction of that; maybe 10% or so. A couple of hundred pounds. Which is far less than their day to day life.
This is why you can't "slip in" thin aftermarket style shims during assembly. It's why a "case spreader" is commonly used in well-equipped shops. It takes a great deal of force to pry a housing open by an extra .015" or whatever, such that when the tool is removed, the housing presses on the bearings with the necessary couple of hundred pounds.
One way or another you have to make the shims too close together for the carrier to just drop in, or for a foil-thickness shim to be able to slip in. Either you need to spread the housing, or you have to apply preload to the bearings before you put them in. One or the other. Without it you'll have a sloppy loose mess that won't last, will make noise, and otherwise be a disappointment.
