taguy16

I'm at the point where I'm putting my pinion back in the housing. I'm using a crush sleeve eliminator as recommended by Sofa Kingdom. When I put it together with all the shims provided in the kit and torque it down as the instructions say to do to 125 ft lbs. I can barely turn the pinion yoke. I reinstalled my races to make sure they were in as far as they will go but I get the same result. The pinion bearing is down as far as it with go with the same shim the old pinion that I'm replacing had. I did the same trick I used for that bearing to install the smaller yoke bearing: heat up the bearing and freeze the pinion. It seems like I need more shims than came in the package for the crush sleeve eliminator, or a longer sleeve.

One issue I had was the old pinion yoke had some sort of sealer it looked like in between the splines that made it hard to push it on and off the pinion, so I spent a lot of time trying to clean all that off so the yoke would slide on easy. Unfortunately it goes on about half way and has to be driven on the rest of the way with an impact gun. It's been a while since I've replaced a pinion yoke or seal so I can't remember if they normally slide on all or most of the way by hand or whether they always have to be helped out a bit with a large hammer or impact.

sofakingdom

iTrader: (1)

If the races aren't in all the way, it will have the opposite effect: the eliminator stack-up would be too short. Think about a front wheel bearing and how you set it. The pinion system is EXACTLY the same thing, except that in a FWB, the "shaft" is the spindle and sits still, while the "bore" is the hub and it rotates. But as far as the bearings are concerned it's the same.

To set the eliminator up, you need to be able to easily remove the pinion from the "tail" bearing. I hone one out with a brake cyl hone until it slides on easily.

Yes the yoke often fits rather tight on the pinion splines. That's pretty normal.

Does the pinion have end play in the bearings when you've got it torqued down?

taguy16

No, there's no end play. I'm pretty sure the tail bearing is bottomed out. The more I tighten the pinion yoke nut up the more the pinion binds up; when I loosen the nut it spins freely and there's no end play. Part of me thinks I just need to tighten the nut as much as possible to make sure the bearing is bottomed out, then loosen it until I get the right bearing preload. The instructions that came with the Raytech crush sleeve eliminator, though, say you should adjust the bearing preload by adding or subtracting shims and the nut should be tightened down to 125 ft lbs when you check the preload.

I drove the bearing races in until they bottomed out (I couldn't drive them in any more and pounding on the driver felt solid. That made the head bearing site slightly inward of the edge of the bore I drove it into.

If the tail bearing slips on the pinion shaft too easily don't you run the risk that it's going to spin on the shaft instead of stay put like it's supposed to do when in use?

sofakingdom

iTrader: (1)

Right: that's the whole point of the CSE in the first place.

Think about a wheel bearing. I keep saying that: THIMK. It's the same thing.

With a FWB, you tighten up the nut to get the preload you want, then use a cotter pin to hold the nut in place. Rear ends USED TO do the same thing, but it's too easy to shear a cotter pin at the speeds and power level that V8 motors make. So to hold the nut still they went to the "crush sleeve" instead. With that, as you tighten the nut, LONG before all the bearing end play is taken up, it begins to compress the CS; if you were measuring the torque on the nut, you'd have very little until then, then suddenly the nut torque would go WAY up as the CS begins to crush; then as you continue to tighten, the nut torque will stay about the same, as the sleeve crushes; eventually you've taken up all the end play and begin to have preload; then you stop tightening when the preload reaches the desired value. Then you have to stop tightening. At that point, the nut has however much torque on it, AGAINST the CS, which holds it still, AS LONG AS the sleeve doesn't crush any more. Problem is, IT DOES: the act of driving the car in reverse presses on the CS EXACTLY THE SAME WAY that the nut does (gear torque in reverse tries to suck the pinion INTO the case, which presses on the crush sleeve), therefore it can crush some more; and when that happens, the nut is no longer tightened up against anything, and it can just back off whenever it feels like it. The CSE allows you to tighten the nut up against something that will NEVER crush any more than at installation and lets you torque the nut as tight as you want without having to stop when the CS is crushed to the right length.

Every time I've used a Ratech CSE, there was at least .020" or .030" too much shim in the kit. There's usually about 5 of them, in thicknesses from maybe .010" or so, up to maybe .020"; total shim stackup something like .070". I usually end up leaving out at least 2 of them to get to the right preload. I have one sitting here that fits some other rears including the 9-bolt (I don't have a 7½" 10-bolt one on hand) to look at, it's just like that. It has 5 shims. They measure: 1 @ .0105", 2 .0115", 1 .0165", & 1 .0195". The main spacer is .4055". Per Ratech's site, the shim pack is the same in the 7½" and the 9-bolt kits, so this should be the same as what you've got, except the sleeve is different somehow.

Your rear can't somehow be all that different from all the others. I'm going to go out on a limb and suspect that your races aren't driven all the way in the housing. Try going to Autozone and "renting" a bushing/race driver. I think the one they "rent" covers the right range. Verify CAREFULLY, with an inspection mirror perhaps, that both races are fully seated.

taguy16

I already have a bearing driver set and that's what I used to drive the bearing races on. If I reach in the bores and try to put something between the bottoms of the races and the ledges that they bottom out against I can't get any else in there so there can't be any gap, meaning they won't in any further.

bcutler

The spacer itself might not be seated on the pinion. I had to radius the spacer on the inside to clear the radius on the pinion to get it to seat properly. I just went through this on an 8.5. I’m pretty sure the 7.5 is similar. The directions mentioned to check that it’s seated. I usually don’t read the directions, but glad I did!

Camaro71

It's 'simple': if you've got too much pinion preload, then you don't have enough shims/distance in between.
Regarding sealant on the splines: it's a good habit. I put gasket sealant to the inside of the yoke on every build. It prevents oil from sipping through. By putting it inside the yoke and not on the pinion splines, you push the sealant outward and not into the case.

taguy16

I do that, too. I believe the stuff I use is #3 aircraft sealant because it says it's for sealing machined surfaces.

TransamGTA350

iTrader: (2)

As others have said, if the crush sleeve eliminator is set up correctly, you should be able to tighten the pinion nut to the 125ft-lb spec and the rotational drag on the pinion bearings should be within spec. If the rotational drag is too much, then there is not enough "height" in the spacer/shim stack. Either more shims are needed, or one or both bearing races are not driven in far enough. Is this a BW 9-Bolt or GM 10-Bolt rear? If its a BW 9-Bolt and you have the pinion shim behind the bearing race and is typical for those, you may need some extra shims for the crush sleeve eliminator.

Setting up the crush sleeve eliminator kit is an iterative process. Put it together, measure pinion bearing drag, take apart, add/subtract shims and repeat until the pinion drag is within spec.