Ring/pinion pattern off...

[john-9]

you tried 0.090 - 0.150 ,,, what was the original shim thickness when you pulled the diff apart ,, in a 742 case should have been in the 0. 86 - 0.095 range ,, depending on the case / gear ,, if say the original shim was 0.090 you should have taken out 0.003 like i stated in my previous post and tried a 0.087 shim to move the pattern up on the tooth on the drive side keep doing this until the drive pattern is at its best ,, centered heel to toe on the tooth ,, the coast pattern will follow . you have to move in increments of 0.003 to see a pattern change and on the 8-3/4 if you have too much toe (inside of the tooth ) which you have remove shim thickness ,, too much heel ( outside of the tooth ) add thickness ,, again in 0.003 increments and run a pattern check with each change. you have to work at it but if these were truly never run new gears the pattern should be close to what is in the pic i posted.

 

[dvw]

got a shim kit from dr diff and spent a couple of hours tonight trying different thicknesses from .090 to .150 and that pattern stays pretty much the same other than moving up or down from crown to root.. soo.. just crap gears i figure.. going to drive them noisy for a bit before i decide what to replace them with. My motor won't make much power so the 4.57s will be fun but i figured i would end up changing them out eventually just not sure what for yet...

I only drive 6 miles each way to work on straight 2 lane roads so just wanna have some fun there and back

Only major issue to figure out now is why the TV doesn't work... car shifts 1-2-3 at the same low rpm no matter throttle.. but thats for another day..

Thanks guys.

Exactly. centering in the crown/root is what you need to do. Toe to heal means nothing.

How To Create & Read Ring Gear Patterns

 

[icetech]

Exactly. centering in the crown/root is what you need to do. Toe to heal means nothing.

How To Create & Read Ring Gear Patterns

Ok.. i was more worrying bout how far up and down the toe/heel they are... will get it centered and run it.. i'm not out anything either way Thanks much dvw.. Itching to get some miles in.. and cold weather is fun for driving (when there isn't show...)

 

[icetech]

BTW.. i have a quick question.. just trying to learn and this is something i have searched for 2 days for but can't find anything.. Where the large bearing meets the pinion head i have a .090 washer with a bevel to clear the radius where the pinion shaft meets the head.. is it possible to go less than .090? I have been searching every term i could think of and i can't even find any washers at all with that bevel in them. And the shims alone wouldn't sit flat on the gear due to that radius in the gear.

 

[icetech]

The one here called and "Adjusting Washer"

 

[Daves69]

yeah, just ordered a shim kit... no spare bearing, when i destroy the old one getting it off i'll order 2 I'm kinda glad it's so far off honestly.. gives me hope of making it quiet.

FWIW, you might check for a hardened shim behind the pinion bearing race. Two I've taken apart have had one.

You may be able to save your old bearing for a setup bearing using a press and sharp splitter. I pull the race and use it cover the bearing then wrap my leather welding apron around it JIC.

 

[dvw]

489 case normally has the pinion shim under the race. Nominal shim is usually between .028-.040"
Doug

 

[icetech]

FWIW, you might check for a hardened shim behind the pinion bearing race. Two I've taken apart have had one.

You may be able to save your old bearing for a setup bearing using a press and sharp splitter. I pull the race and use it cover the bearing then wrap my leather welding apron around it JIC.

K.. i had no idea the race could have a shim behind it... I will double check that tonight... it's like with the .090 washer i can't move the pinion out enough, but can't remove that washer and just use shims cause of the radius on the shaft. I pretty much can't even find pics of that washer online let alone if i needed to buy one i would be screwed.

BTW, i bought a clamshell bearing puller and man that thing is worth every penny, although i'm glad i saw a video where you put a spare race over the bearing so it doesn't hurt the cage when pulling... I then honed out the bearing so i can pull it on and off by hand. Little tricks like that are worth gold

Thanks for the help btw guys.. i feel like an idiot posting this ****.. but it's how i learn..

 

[Daves69]

.....i feel like an idiot posting this ****.. but it's how i learn..

Welcome to the club!

 

[icetech]

K.. think i figured out what's causing my issue.. going to experiment when i get home.

 

[icetech]

k.. so i have never done bearings/shims on a pinion before and my pinion has a radius at the bottom of the stem/shaft(pic below) i thought they all had that.. and it has a .090 shim with a bevel in it to clear that radius.. so i figured that was normal and couldn't find anything like that to go thinner.. then watched some videos today and looked at pics of pinons and none have that radius and shims go right down to the gear.. so i had a .065 shim in my kit, i opened it up enough to fit over that radius and now i can go with less shim.
I tried .065 and .077. The pics below are .077.. i'm off the root a bit now maybe too much on the crown. Go to .080-.085? still a weird pattern though, coast side especially. This is with .010 backlash.
Pic of the radius i was talking bout..

 

[AR67GTX]

From the pattern I think the pinion may still be too deep but apparently the .065 shim looked worse so, so much for that. You’re right it is a wierd pattern. I think your thought of trying an .082 to .085 would be a good idea at this point. And instead of .10 backlash I would shoot for a little tighter (.08) but the backlash is probably not going to change the pattern. It will tend to open up after you run it awhile so best to start out on the side of less.

Good luck.

 

[dvw]

k.. so i have never done bearings/shims on a pinion before and my pinion has a radius at the bottom of the stem/shaft(pic below) i thought they all had that.. and it has a .090 shim with a bevel in it to clear that radius.. so i figured that was normal and couldn't find anything like that to go thinner.. then watched some videos today and looked at pics of pinons and none have that radius and shims go right down to the gear.. so i had a .065 shim in my kit, i opened it up enough to fit over that radius and now i can go with less shim.
I tried .065 and .077. The pics below are .077.. i'm off the root a bit now maybe too much on the crown. Go to .080-.085? still a weird pattern though, coast side especially. This is with .010 backlash.
Pic of the radius i was talking bout..
View attachment 1752998


View attachment 1753000

View attachment 1753001

What does the pattern look like on the pinion?
Doug

 

[icetech]

What does the pattern look like on the pinion?
Doug

I'll take a pic tonight when i get home.. didn't think bout it last night.. thanks

 

[icetech]

K.. so this is .080 with .008 backlash.. I think this is bout as good as it's gonna get.. just crap gears, not gonna complain, will run em til i figure what i want to do in the future i think.. At least i have a bunch of practice taking it apart and putting it together always good to learn things..

 

[AR67GTX]

Are you sure that’s a matched set of gears? Do you know the source? Your coast side looks like mine did when I got it back from the shop and it howled/whined on coast and light cruise. After running a whole bunch of patterns I took .003 off the shim and ended up with this on the coast side and .06 BL.

I’m not sure it’s a great pattern but it’s a lot better than what the shop gave me below.

But this is a 489 set up and maybe that makes some difference with pinion set up. At least what I thought would make a difference isn’t working out for you. Are you putting as much drag as you can on the ring gear while turning the pinion for a pattern impression?

 

[khryslerkid]

Drive side still needs to come up. Get the drive side right and let the coast side fall where it does.

Last set I did I couldn't get both sides even. Went with a good drive pattern and didn't worry about the coast. They don't match/lap gear sets anymore. They just apply the break in sulfur coating. The last set whines around 50 mph and quite below and above.

 

[icetech]

Drive side still needs to come up. Get the drive side right and let the coast side fall where it does.

Last set I did I couldn't get both sides even. Went with a good drive pattern and didn't worry about the coast. They don't match/lap gear sets anymore. They just apply the break in sulfur coating. The last set whines around 50 mph and quite below and above.

by up you mean towards the crown? There is maybe 1/16th of a inch or less left there.. with the .072 it was almost nothing..

 

[icetech]

Are you sure that’s a matched set of gears? Do you know the source? Your coast side looks like mine did when I got it back from the shop and it howled/whined on coast and light cruise. After running a whole bunch of patterns I took .003 off the shim and ended up with this on the coast side and .06 BL.

View attachment 1753564

I’m not sure it’s a great pattern but it’s a lot better than what the shop gave me below.

View attachment 1753566

But this is a 489 set up and maybe that makes some difference with pinion set up. At least what I thought would make a difference isn’t working out for you. Are you putting as much drag as you can on the ring gear while turning the pinion for a pattern impression?

No idea on matched set.. i assume it would be but no telling.. i'm gonna get it good enough to run. the noise wasn't so bad that i can't live with it, just figured i would double check it and try to get it better if i could. Now i know what to do when i change down to a more boring gear though.

 

[Daves69]

Maybe something as simple as this can help in the future..............

Click here forPinion Setting Tool Diagram

I scored this installation kit some time ago cheap. Occasionally they show up on Ebay.....