Need advice on gear patterns

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n.y.340 dart

n.y.340 dart

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Looking for advice on my gear pattern. This is my first time setting up gears. 83/4 742 case. New Richmond 4.10 gear. This is my first pattern. 008 backlash. 2.717 pinion distance as on the flat of the pinion. I appreciate feedback, thanks!

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I agree with roy. I think it's just a tic deep, but if I was settin one up and got that pattern, that *****'d be ridin.
 
I appreciate the input. I will play around with it tomorrow. Thank you! It’s so easy to start second guessing with these things!
 
Try thinning your pattern compound. Try just a drop or two of oil mixed with the paint will thin it out and give a better reading. Also, are you prying the ring gear/spool away from the pinion while checking the pattern? Those things may help your readings. I always tried to avoid sharp lines on the witness marks. I haven't done a set in a couple decades, so my memory is a little faint.
 
n.y.340 dart said:
I appreciate the input. I will play around with it tomorrow. Thank you! It’s so easy to start second guessing with these things!
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rustycowll69 said:
Try thinning your pattern compound. Try just a drop or two of oil mixed with the paint will thin it out and give a better reading. Also, are you prying the ring gear/spool away from the pinion while checking the pattern? Those things may help your readings. I always tried to avoid sharp lines on the witness marks. I haven't done a set in a couple decades, so my memory is a little faint.
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This above, was something I failed to mention in my response. When you pry on it (I pry on the differential itself in a manner to increase friction while turning the gears, but you have a spool, it looks like, so you can only pry so much - if at all, because of the depth), you simulate a "load" on the unit, much like (but not exactly) the gears will face when turning your axles / wheels. Often, the gear pattern will change slightly. In your case, though it is slightly deep, I wouldn't change it. As Rusty says, run it.
 
New gears I like .04 back lash but I like your pattern a little deeper won’t hurt .
 
As post 8 is saying ! I’ve never say pry on anything when setting up my gears ! I think though they are saying the same thing I’m fixing to say ! Hey I’ve always loaded the ring and pinion while I was turning it just by putting pressure on the ring gear as best I could with my hands and rag ! As post 8 says you want to load it as the axle is turning it ! Actually I’ve never thought about prying on it ! I guess as long as your prying in away that the axle is turning the ring gear should work though ! Not sure , just never did that ! Pattern looks good IMO ! In most cases the pinion depth shim that comes off the old pinion is a great one to start with, in most cases that I’ve done that was shim I ended up using anyway ! Not ever time , but most . I don’t remember if the 742 case has a crush sleeve or shims for your pinion bearing pre-load, if it has the shim or shims I would also try what you take out and see what you have … Good job
 
rustycowll69 said:
Try thinning your pattern compound. Try just a drop or two of oil mixed with the paint will thin it out and give a better reading. Also, are you prying the ring gear/spool away from the pinion while checking the pattern? Those things may help your readings. I always tried to avoid sharp lines on the witness marks. I haven't done a set in a couple decades, so my memory is a little faint.
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Thanks for the tip. Yes was prying on ring gear
 
Is it set to the actual depth number on the pinion ? Same with the backlash ? If it is, I think the pattern looks very good and I would run it. I have got into a process that I double check the backlash after the gears are broken in, for my piece of mind. I just checked one that I did years ago, with alot of races and street miles. Had over. 022 backlash, and the end of the ring gear was cracked.
 
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Pattern Looks good to me.... Back lash could be a little tighter 0.04 or 0.06. then just let it loosen up to it's happy spot.
I say send it !!!!
 
oldkimmer said:
U can disagree all u want, but your still wrong. Kim
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I don't know which of YALL is right, but I CAN tell yall this.........

The pinion gear tries to climb the ring gear. This is what causes the axle housing to rotate the opposite direction of the axles. That's the force that's taken advantage of when using SS leaf springs, Cal Tracs, or traction bars. That's the force that makes traction bars slap the leaf spring eye on acceleration. It all comes from the pinion trying to climb the ring gear. Since of course it cannot, since it's housed in the case, it does the next best thing and makes the housing rotate the "other way".
 
rustycowll69 said:
I disagree. The gears try to repel each other. That's why you have all those structures to hold them in mesh. Kinda like a Phillips screwdriver in a Phillips head screw head.
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This is what happens. The pinion is trying to climb the ring gear and shove the carrier right out the back of the housing. That’s one reason why they break caps the way they do.
 
Update dropped the pinion depth a little. 007 backlash, really tried to put a load on gears when rotating gears for pattern check. This is what I got. Might just go with it. It has a spool. What do you guys or gals think? Thanks.

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