Need help interpreting gear pattern

mikalcarbine

mikalcarbine

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I'm setting up new 4.88 gears in my Dana 44 with my ARB. I could use some input on interpreting these patterns

This was the first pattern I pulled and didn't write down the specs, it was at 42 thou pinion depth and maybe 7-8 backlash
42-8.jpg


The numbers below indicate inner pinion shim/outer shim/RGS shim/NRGS shim and B/L that I've been using for reference

49-65-18-15-7.jpg


50-65-13-20-7.jpg


53-70-18-15-6.jpg


53 seems too deep but I'm struggling to interpret what 49 and 50 show. I'm trying my best to get the carrier loaded when checking the pattern. The axle is on my bench so it's been tough. I've been using a small piece of wood between the carrier and a pry bar. Any tips would be appreciated!
 
I’m going through a regear now as well and hosejockey61 suggested using a cordless drill on low speed to turn the pinion while using a heavy leather glove to apply pressure on the ring gear to get a decent pattern read. I tried it and it worked great. My axle was also on the bench.
 
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X2, definitely put more pressure on the ring gear. Even wedging a piece of scrap wood would help
 
i'm an amateur at this as well, only done 1.
but 53 looks deep. 49-50 don't look to deep but don't look quite right.
42 looks good placement, but a hair shallow...........i'd try a 44-45 and good tension on the gear to get a good swipe.

and it may not matter sure i'll get corrected but i don't run back n forth across the grease. run the gear 4x all the way around 1 way then 4x around the other way, not back n forth.
 
Thank guys, I set the pinon to 44 and tried running a pattern by rotating the carrier and holding the pinion under pressure with a towel. I might need to clean the gears before trying another pattern. Thoughts on this?

44-60-20-13-7-2.jpg


My novice eye thinks this looks much better than 49. My backlash was 6-8 thou when checked in 4 different spots on the ring gear.

When looking for depth are you looking to see what this spot looks like/ends up between the root and crown?

depth.jpg


From searching on google some people have a very small contact pattern or have something long similar to mine
 
@Rob5589 would know. He’s gracious enough to keep coming back and helping people with these patterns.
 
lookin at the 44 vs 49, think 46-47 your there...............but wait for Rob.

i follow these threads to learn, so i am interested to hear his interpretation.
 
Your backlash looks incorrect. I'd put another shim on the ring gear side and decrease the the otherside.

When applying pressure, keep it on the ring gear, not the pinion (unless you misspoke)
 
All good advice here. To answer your question about cleaning the marking compound before running a new pattern, YES. It definitely helps to remove as much compound as possible. I found that brake clean and a soft bristled brush worked well to kinda loosen things up. Then wipe it down with a towel. You won't able to clean much off the pinion but the majority will be on the ring gear anyways. Keep working at it, you'll be glad you took your time to get it right.
 
tworley said:
Your backlash looks incorrect. I'd put another shim on the ring gear side and decrease the the otherside.

When applying pressure, keep it on the ring gear, not the pinion (unless you misspoke)
Click to expand...

Are you saying that because the pattern has too much toe?

SvtLdr said:
All good advice here. To answer your question about cleaning the marking compound before running a new pattern, YES. It definitely helps to remove as much compound as possible. I found that brake clean and a soft bristled brush worked well to kinda loosen things up. Then wipe it down with a towel. You won't able to clean much off the pinion but the majority will be on the ring gear anyways. Keep working at it, you'll be glad you took your time to get it right.
Click to expand...

To get those most recent patterns I spun the carrier per some advice on another forum, the Yukon manual that came with my gears indicates that's the way to do it as well. I keep seeing mixed on this but I was spinning the pinion with my original patterns just because it was easier.

I'm going to try 46 for the hell of it and I'll post it up shortly. I clean up the gears before running this pattern
 
I just turn the pinion with a drill adapted to 1 1/8" socket and create as much drag as I can with a glove on the ring gear OD, try to keep the marking compound thin but well coated (too thick can make sharp lines in your pattern that aren't really representative)
 
If you haven't, mix in a couple dollops of gear oil into marking compound, it helps the pattern come out clearer. That way it doesnt dry and you don't have to clean, I just repaint over.
 
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I tried a pinion depth of 45,46 and 47 but my main concern right now is trying to get the pattern centered between the heel and toe. With my pinion at 46 moving the backlash from 0.006 to 0.010 had no impact on the toe/heel contact. I even moved the pinion a few thousandths while maintaining backlash shimming with little change. Any thoughts?

44-60-20-13-7-2.jpg


45-60-20-13-7-2.jpg


46-60-18-15-6.jpg


47-60-20-13-7-2.jpg



The drill idea was great. I wasn't sure if I was loading the carrier enough so I put in both axle shafts and my girlfriend helped me hold one while I loaded the carrier by resisting the other shaft while turning the pinion. The pattern didn't change so I know I'm loading everything good

I have plenty of other photos but didn't think posting was helpful. I can post a set of 6 vs 10 backlash if anyone is curious
 
You're too shallow. Make a BIG change (10 thou) and try to find your "goal posts". If you keep making minute adjustments you'll never know if you are where you need to be. I think the pics you have posted are one goal post. Now find the deep side one and then work within those parameters.

I know it may seem like a lot of work but you will gain a ton of understanding and feel for how the relationship works. By the way, your marking compound looks more like chalk than paint...thin it with some gear oil.
 
hosejockey61 said:
You're too shallow. Make a BIG change (10 thou) and try to find your "goal posts". If you keep making minute adjustments you'll never know if you are where you need to be. I think the pics you have posted are one goal post. Now find the deep side one and then work within those parameters.

I know it may seem like a lot of work but you will gain a ton of understanding and feel for how the relationship works. By the way, your marking compound looks more like chalk than paint...thin it with some gear oil.
Click to expand...

Here's 54 from earlier when I first started. I started at 42 and went directly to 57 but it looked too deep to my untrained eye so I backed off to 54. Unfortunately no photos of 57 but it looked deep towards the root

54-13-20-8.jpg


I am thinning out my marking compound with gear oil but I'll keep using more. I went a little thick on some photos to test how the pattern prints vs much thinner. Didn't seem to make a huge difference
 
Your patterns are inconsistent and have inconsistent tooth markings (at least to me). Do you have enough carrier bearing preload? If not, that might be the problem. If you aren't using a case spreader, then it should require several (at least) strong blows with a dead blow hammer to get the carrier/locker to seat all the way. Are you installing the bearing caps each time as well?
 
hosejockey61 said:
Your patterns are inconsistent and have inconsistent tooth markings (at least to me). Do you have enough carrier bearing preload? If not, that might be the problem. If you aren't using a case spreader, then it should require several (at least) strong blows with a dead blow hammer to get the carrier/locker to seat all the way. Are you installing the bearing caps each time as well?
Click to expand...

To be honest from the guides I've read I've been tightening my pinion only enough to set the bearings. I've been using 100ft lbs and 20-40in lbs of pinion preload. As for the carrier I have the shims set to take up the "empty space" and a maybe a few thou more. I've been using this guide which states that the carrier preload shims can be put in after testing patterns: https://www.pirate4x4.com/articles/tech/billavista/Gear_Setup

Either way, it does take a few whacks of a deadblow to seat it all in. I built a case spreader but have not been using it yet. I can try adding a few more thou of shims and pulling out the case spreader if necessary. What do you think?

Edit: I can double check 57 again tomorrow, I know a lot more now than when I first started and that was literally the second pattern I ran
 
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