You are a lot closer than you think. Don't change anything yet. I cant see the pattern on the drive side very well, you don't have enough load on the ring gear. The shadow I do see looks like it is wide in all directions and positioned to the toe. If that is it you are there. I cant see it however so it is very possible "wishful thinking"! The coast side is too deep. That will howl when you back off the gas. Get the drive side first. Make sure the backlash is correct. On a used gear set use the larger specification for backlash (.010"). We might tweak the coast side with the backlash. More on that later if needed.
You are on track. The number was twenty thousands on the shim. Lets see what a good clear mark looks like. More drag on the ring gear. You should not be able to turn the pinion easily by hand. If you are pushing something against the ring gear, be careful you don't want to crack the axle housing. Use a wedge block of wood (like a doorstop) or nylon against the ring gear and the case. I did see a guy break the case using a crowbar against the ring gear. Roll the ring and pinion several revolutions with load. Look for the marks on the opposite side of the paint spot. See what the marks look like out of the paint. Your getting close. Shoot pics of the painted spot and the unpainted spots where the gear transfers the paint.
If you have the preload set on the carrier bearings (you should have .015" of preload), just move shims from one side to the other to change backlash. Keep the total shim pack the same. So take from one side and add them to the other.
Will get a better pic with load but my preload on carrier bearings is not right yet. How do you know when u get the proper pre load on carrier bearings ? Im gonna get a new set of carrier bearings and make some set up bearings . This reminds me of the movies when they played serials when I was a kid ," Commando Cody " comes to mind had to wait a week for the next serial ha.
You need to set the carrier preload without the pinion in. With no pinion it should take a firm steady pull to rotate the ring gear. It is hard to measure but if you put a torque wrench on a ring gear bolt, at least 50 or so inch pounds to rotate it. To set it by the book, you find the right amount of shims to obtain a "slip fit" of the carrier in the axle's housing. Then .015" is added to the bearings to obtain the proper preload. Once you "feel" one assembled this way, you will always know what the proper preload feels like when you pull on the ring gear with no pinion in the housing. The second link below address the set up of the carrier preload pretty well.
I have seen guys make their own axle dummy bearings for setting up axles. It works quite well. Take a used set of bearings and hone with a "brake cylinder hone", the I.D. of the races until they will slip on the carrier and the pinion respectively. You can also epoxy the bearings together to make the "tool" into a solid dummy bearing. This makes it much easier. Use the slip fit bearings to quickly swap the shims in and out until you get it set.
Got some clearer pics bmorgil . First one drive side and other coast . Still looks like I need to move pinion out some . But my ring bearings not set right yet , the preload . Looks like drive side hitting on more of the toes and to deep. If not still to clear ill try again .
You are good at this Wulfie. I am in agreement with you. There are some clues. Look at the "ghost" marks where there wasn't paint. The marks left by the teeth almost match the original wear pattern. You are very close. I agree it is to deep. I am concerned about your carrier bearings not being set. You need to have them set before the final pattern. That said, I have to think bring it back out about .010" and tighten up the carrier bearing preload (first) before the pattern check. Notice how now, the drive and coast side are closer to the same deep contact pattern and moving to the toe on the drive and the middle on the coast side. That pattern is almost there, a little too deep. Your .020" adjustment successfully moved it right through the sweet spot. That tells us you were within .020". Since it moved it from too shallow to too deep, you know you were within .010" of hitting it.
I misinterpreted your question about the preload shim change. I was talking about the carrier shim pack. You are correct the preload will change on the pinion as you move it. Hold off on the pinion preload adjustment until you are done with pinion depth. Remove most of the shims from the preload and tighten the pinion nut gently until you achieve some preload (not too tight you will ruin the bearing). Set the pinion depth and then go back and set the preload.
Addition: Shoot pics of the pinion if you can get the camera in there. The long teeth also give some good indications where the paint transfers from the ring gear. I have always found it to be faster to make large changes in the shims until you can successfully go past optimum and then bring it back. I find this method much quicker than "sneaking up" on the pattern.
Tnx bmorgil , after lasft pattern i took out .007 but havent tried it until i get carrier pre load set up . I assume the .015 is divided between the 2 sides ?
The .015 is added to the pinion gear side, once the total amount of shims required to move the ring gear to Zero lash is obtained. The procedure to get it correct is to find the amount of shims required to slip the carrier into the axle housing to a slip (Line to Line) fit. Then you remove the shims and install the ring gear and the pinion. You then force the pinion into the ring gear while indicating the amount of travel. Then you place that amount of shims from the total amount you measured for a slip fit, on the ring gear side. Now you place the remainder of the shims on the pinion gear side PLUS the .015" required for preload. The .015" pushes the ring gear away from the pinion for backlash and provides the preload. The carrier is now a .015" press in fit into the housing. This should put the backlash within spec. From now on as you adjust backlash you remove shims from one side and move them to the other side. On a used ring and pinion shoot for .010" of backlash. If it needs to be less it will show up in the pattern.
After another look, I was also thinking .007" on the pinion. It looks close.
Got another addition to pic of gears , first drive side second coast side . Also some shoes for "RIPPER" , and another bunch of goodies from Walcks , they sure pack em good . Got the .01 backlash right now if nothing changes lol. Suspect maby one more move out on the pinion , a lil more . Wish I had done the .01 .
Man that's close. Classic used gear set, wont leave a good mark unless its in the exact spot as before. I am in agreement again, damn I though .007" also. Looks like the .010" would have done it, .002" or .003" more might show a better pattern. Because the gears have run together for so long, it will be difficult to get a good print on the pattern unless you hit it exactly in the position it was in when it came apart. We are looking for a clean spot near the center of the tooth. If you look hard you can see you almost have a nice contact. It is not a picture perfect clean spot like a new gear set but, it is there just not real clear. Make sure to hold the .010" backlash.
Thinking .003 . And the carrier pre load seems correct now , added .014 to teeth side . Tight fit now around 40 inch pounds . If I move pinion out will it change backlash , which I think it will.