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!