I am setting up axle gears for the first time...in a d60 rearend. I have the booklet from Randy's to go by as well as another repair manual.

After spending about an entire day assembling and dissasembling, I finally got to test a pattern that is maybe acceptable.

The contact patch is centered from face to flank, but not centered from heel to toe. The pattern is on 1/2 to 1/3 of the tooth, towards the inside, (toe?) Is this acceptable??

According to the book from Randy's it might not be possible to center the contact patch from heel to toe, and as long as it is centered face to flank, the pinion is the correct depth and it will work OK.

By the way the backlash is also within spec. They are the original gears that were in the housing, I am just adding a detroit and new bearings.

Dan

I'm no expert, and it's hard to say without seeing the pattern, but it sounds like you need to remove .010 from the pinion and go from there. If the pattern moves to the heel side, add some. The backlash must be within spec before reading the pattern. Take your time, you'll get there.

Also check the pattern in a few different spots on the gear

you prolly need to post a pic before anyones gonna really be able to help ya....

-yag

The backlash is within spec, .006, here are a couple of pics...hopefully they are clear enough.

Dan

http://pacific.photoisland.com/photosharing/albumindex.html (http://)


Thanks

Dan

You really need to post a picture. Get some GM marking compound if you don't have it. This Ford guy admits that it is THE BEST: much easier to read, and should also photograph well.

You might need to set the backlash toward one end or the other of the acceptable range in order to optimize the pattern. Changing the backlash will move the pattern quite a bit in the heel-toe direction, which is counter intuative. Try shimming for a little more backlash (but stay within acceptable limit) and see if that don't push the pattern toward the heel.

Remember that there is nothing "better" about setting the gears at the minimum end of the range.

One thing to take care of when reading contact pattern is to look at the shape of the pattern, not just where it is. If one edge of the patch is fairly straight or square, then the pattern is shifted in that direction. When the edge is has a definate curve, then you are seeing where it really is. As Randy says, it is most important to get a nice curve on both the face and flank edges of the pattern. You can compromise the heel-toe a little. Also, on one set I did, I found I had to compromise the coast side pattern a little in order to get a really good drive side pattern.

Edit: You put the link to the pics up while I was typing the above.Unfortunatly, the link don't work.

BTT- How do I post a pic? They are on a photo sharing site but apparently the link to it doesn't work??


Dan

You need to donate $20 to PBB and get a red star, or put them elsewhere on the net and link to them.

Since you're resetting used gears it's a good idea to set the coast side as close to perfect as possible. I'd think since it's the same gearset you'd only need to remove .003" at the very most of pinion preload shim to account for the housing settling a hair over time. The depth shouldn't need to be adjusted, only backlash and carrier preload to get the new carrier dialled in.

Here are the pictures again...hopefully the actually work this time.

Thats what I was thinking about the pinion depth too, if it is the same gears and same housing, and only the carrier changed it doesn't seem like I should even have to mess with pinion depth.

Dan

gear pattern (http://mediaservice.photoisland.com/auction/Apr/2002414052816304356842.jpg)

gear pattern 2 (http://mediaservice.photoisland.com/auction/Apr/2002414170281361566039.jpg)

That's no where close!

How are you measuring your backlash?

just to give you an idea, here's the pattern on my 44,



http://home.earthlink.net/~mattsara/bb/44drive.jpg

http://home.earthlink.net/~mattsara/bb/44coast.jpg

i would be adding about .005 to that for starters

I agree.

It looks like the pinion is nowhere near deep enough. (needs thicker shim under inner bearing)

The fairly sharp, straight edge which follows along the face is what I was on about in my previous response.

Look at the pictures Nobody posted. See how the edge near the face is softly defined, and quite curved, and note that the curve of the contact pattern does not follow the shape of the gear tooth, like it does in your current pictures.

Nobody's coast side pattern has a sharp edge near the flank that indicates the pinion may be running a little deep, but that might be a trick of the camera angle, or that may just be how those gears turned out.. The pattern is quite wide and covering a lot of the tooth, so they may be used gears that wore themselves that way. If they run quiet, and last, that is the proof of the pudding.

Ideally, for new gears, you'd want rounded edges on both the face and flank sides of the pattern. It may be that it goes flat near the center of the pattern. In that case you want about equal percentage of "flat" on face and flank sides.

I missed where you indicated these are used gears. Slagburn is correct about optomizing used gears for the coast pattern.

Edited to correct typo pointed out below.

Thanks for the replies, as you can tell I have never done gears before.

So my pattern isn't even close? I'll tell you how I got it to where it is.
-used original shim thickness on the pinion depth
-checked backlash and got it within spec, or so I thought.

I measure backlash at .006 with a dial indicator, and it is supposed to be between .006 and .010. Unless I am doing something wrong or missing a decimal place or something...it seems right. If you move the ring gear, you can feel the backlash but it is very slight.

So it sounds like I need more shim under my pinion? is this right. Man this is more difficult than I thought.

Dan

are you using a magnetic base with the dial indicator? Are you sure the bearings and races are seated completely?

Yep, it will test your patience alright. Patience is THE most important tool for setting up gears correctly. It could be worse. you could be doing it outdoors, under the truck, in the snow!

It sounds like you probaly have the backlash about right...6-10 means just enough to feel it. But DON'T go by feel.

Are you sure you didn't lose a shim from the pinion?

Also, you might tell me your trick for re-using the shims. I always mangle them with the bearing seperator, so even if nothing changes, I have to mic them and replace with new ones. If you did that, then double check your measurements and addition.

Yes I am using a magnetic base for the dial indicator. I said the comment about it "feeling" right just so you guys would know the backlash is probably right.

So what I have determined is that I need to either put more shims under the pinion, or take some out...which one?

On reusing the shims, I really didn't I just measured the old ones with a mic and set the new ones the same.

Dan

You need a thicker stack of shims under the inner pinion bearing.
GearMan's suggestion of .005 more is as good a place to start as any.

That will screw up your backlash setting, so you'll have to fuss with carrier bearing shims to get that right again. Then you can check your pattern again. Ain't this fun?

Originally posted by Kevbo
I agree.

In that case you want about equal percentage of "flat" on root and flank sides.



hey bud.. not to be nitpicky but the root and flank are the same thing.. just as face and crown.. i guess just a typo but wanted to point it out..