Pinion Depth on 8.75 741 case

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StrokerScamp said:
If it's too loud to put up with, you can try giving it a touch more pinion gear depth. Maybe like .010". Noise on coast indicates too much contact on the outside of the ring gear.
Click to expand...

well i guess i'll pull it again... learned to next time just use the 742 case and buy new gears...
 
I'm lost. What's the 742 case got to do with it?
 
Sometimes used gears aren't a bargain. I have a set of 4.56s in my Chevelle that were perfectly quiet in another car and are noisey in mine. No matter where I set it. Just the way it is, Used gears set a pattern and if you dont get them exactly in that pattern (which is one in a million) they will make noise somewhere. The case makes no matter, but the gears do.
 
Well..you do know that those specs are just for a guide, right? You hardly ever end up right where they say pinion depth should be. The marking compound is where it's at. You get it close with the spec and zero in on it with the compound. I always hone out the old large pinion bearing for a slip fit so I can change pinion shims until I find the right ones. Beats having to press it on and off a lot. When you find the right shim and pattern just press the new bearing on and you're done.
 
StrokerScamp said:
Well..you do know that those specs are just for a guide, right? You hardly ever end up right where they say pinion depth should be. The marking compound is where it's at. You get it close with the spec and zero in on it with the compound. I always hone out the old large pinion bearing for a slip fit so I can change pinion shims until I find the right ones. Beats having to press it on and off a lot. When you find the right shim and pattern just press the new bearing on and you're done.
Click to expand...

ive just been putting another size shim under the bearing cup... gives you the same result with alot less work...

but i have no shims under the bearing cup so it looks like i'll be pulling the bearing off the pinion and seeing where to go from there...

and i never checked pinion depth cuz i have nothing to go off of... thats why i started this thread in the first place lol... but yea just gonna have to yank it again...
 
ok so i got it out again...

here are some good pictures of the pattern... seems like they are to far on the heel=inside?

bearing preload was good...

whatcha think? again thank you guys

also i pressed the bearing off the pinion and there is this huge spacer, you can see it in the second pictire next to the sleeve... its .093"... is that a spacer or shim (nothing else under there)?
 

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Yeah that does look like the contact is a little too far in.
 
StrokerScamp said:
Yeah that does look like the contact is a little too far in.
Click to expand...


on this diff site im on it says "Toe contact, move pinion away from the gear" then shows a pic much like mine...

so it is refering to pinion depth not backlash?
 
Yes. Backlash has nothing to do with rear gear whine. Pinion gear depth. Tatoo it on your forehead. lol Move that cantact pattern to the cenrte and your noise will be gone. you said at first your noise was on coast....then you said it was lousest with your foot just in the gas. That's noise on accel. lol The pattern you have now backs that noise up because it is too clost to the inside of the ring gear. Center it up and you'll be good.
 
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