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Ring gear check

tirewater

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Eh, having some trouble getting a "perfect" imprint when adjusting my gears. These are my original gears, so they're well worn. From the gear experts, what's the consensus here?

The Ford book mentions to adjust backlash to move the imprint from the toe to the heel, but even adjusting backlash to 015" (spec is .008"-.012"), doesn't seem to affect the pattern.

Adjusting pinion depth does affect the pattern. It'll push the drive side toward the heel, but then the pattern is pretty shallow and the coast side is way out to the heel.

Patience...:)

Edit: On reading some Spicer documentation, it appears that used gears tend to favor the toe side and that user should concentrate on centering the pattern between the root and top of the teeth rather then worrying too much about heel-toe.
 

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okorangebrnco

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What shim is under the pinion? What is the lash currently at? But by the looks of the picture, Id run it.
 

okie4570

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What axle and what do they suggest for pinion depth? I've got zero experience installing used gears, are those pics taken with the same pinion depth?
 
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tirewater

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Pinion depth shim is .010. Backlash measures between .009 and .012. I tried to increase backlash to .015 to get drive pattern off toe, but it didn't affect it so I put backlash back.

I am unhappy with the .003 run-out so I may tear it all a part to check ring hear seating as it was very tight going on LSD.

Bleh, given time spent setting up I should have bought new gears and had a decent pattern to work with.
 

66BlueGoose

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So this is a rebuild, just for the LSD? What all did you replace? What was the contact position before tear down? What where your shim stacks before teardown? How to they compare to what you have now?

I ask because once gears settle in, they generally like to run in that spot, I would only change that if it was a bad position and if so, would more likely consider a new gear set.
 
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tirewater

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So this is a rebuild, just for the LSD? What all did you replace? What was the contact position before tear down? What where your shim stacks before teardown? How to they compare to what you have now?

I ask because once gears settle in, they generally like to run in that spot, I would only change that if it was a bad position and if so, would more likely consider a new gear set.

Hi 66Blue, I installed a new LSD with a master install kit. This included new pinion and carrier bearings. In addition a different (used) pinion support is being used.

I did not get a reading from the old setup. There was heavy flaking on the axle side of the original pinion bearing inner race. In addition carrier bearing preload was non existent as the carrier had moved enough to ruin the bearing cage.

The pinion bearings were Tyson (likely original). The carrier bearings were Timken, so it appears someone has been in here before. Especially since an open carrier was in place of the original trakloc.

The pinion shim that came out of the unit was ~.023. The images above are with a .010 shim. I did do a pattern check with a .020 shim (as close to original as I could get). The pattern was less deep, but otherwise had the same imprint shape.

From what I can tell, I can simply center the pattern on the tooth face, set backlash and run it as I can't adjust the heel/toe very well with used gears. Or buy a new gear set.
 

66BlueGoose

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Good additional info. Sounds like things were moving around a bit due initial stages of pinion bearing failure. If you were using the existing pinion carrier, the .023 shim would be the right place to start. New pinion carrier kind of throws that out the window, good that you have checked the .020 to see what that would get you, if .010 looks better than I would run that. I think the .009 to .0012 backlash is reasonable.

I think its going to be tough getting clean reading on the existing gear set due to uneven wear. I think as long as the tooth surface's don't show any damage, you are ok to run them.

My guess is you have it as good as it might get for the exiting gear set and my guess is it will run fine. If you want a better match, probably need that new gear set.
 

pcf_mark

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I have not set up a 9" so my feedback may be less helpful but hypoid gears are hypoid gears. Not getting the backlash before taking it apart is setting you up for a noisy gear set. It will still run fine and live long if set up just noisier.

You pattern appears to be at the extreme inner edge of the gear tooth and should favor the front third to middle. This would make install a shim the sent the pinion further into the housing. I hate to say thicker or thinner because I an not sure which side you shim is on but you should know from looking at it. If you are already at the extreme inner edge when the great gets loaded the pinion will put the force on the inner edge and not use the whole tooth.


How are you getting the pattern? The sharpness to the edge of the pattern in the root of the tooth should be a smooth soft edge. You may have too much backlash. You need to drag your hand hard on the ring and turn the pinion with force to leave a neat pattern not just turn it.

Good luck. Old gears and new bearing I would set up close .008 / .010.


This guy has some awesome up close pics. http://1970boss302.blogspot.com/2012/05/
 

Rustytruck

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Looks like your not loading the ring gear enough whi l e you turn the pinion.
 
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tirewater

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Thanks guys. I'm simulating drag on the gears, mostly by pressing on the ring gear while turning the pinion. I can try to add more drag to see if that flattens out the imprint.

I agree about thicker/thinner pinion shim nomenclature not being descriptive enough as the Ford 9" with the separate pinion assembly shim size is reverse of most housing with the integrated pinions.

Thanks for the link. I've been using www.gearinstalls.com quite a bit. I had Ken (the owner of gearinstalls.com) rebuild my land cruiser 3rd about six years ago, although he didn't list the tear down on his page. I toyed with sending him my 9", but thought I could do it at home.

I decided to just buy new gears and start over. It means redoing pinion bearing preload, and removing red locktite ring gear bolts, but the pattern should look better.

Looks like your not loading the ring gear enough whi l e you turn the pinion.

My guess is you have it as good as it might get for the exiting gear set and my guess is it will run fine. If you want a better match, probably need that new gear set.

I hate to say thicker or thinner because I an not sure which side you shim is on but you should know from looking at it.

This guy has some awesome up close pics. http://1970boss302.blogspot.com/2012/05/
 

66BlueGoose

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Checked some notes of mine. I show the .020 shim as the being the Ford Factory Base shim for pinion depth. Just others reference, smaller shim increases pinion depth towards toe, larger shim decreases pinion depth (move towards heal). You said you got no change with the .010 vs .015 change. I reread and noticed you get some change moving towards the middle with the .020 shim, how much? Do you have a picture of that one?
 
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tirewater

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Checked some notes of mine. I show the .020 shim as the being the Ford Factory Base shim for pinion depth. Just others reference, smaller shim increases pinion depth towards toe, larger shim decreases pinion depth (move towards heal). You said you got no change with the .010 vs .015 change. I reread and noticed you get some change moving towards the middle with the .020 shim, how much? Do you have a picture of that one?

I didn't get a change when adjusting the backlash to .015. I thought increasing backlash would move the drive side mark more toward heel. It did not.

I attached the pattern with the pinion at .020 shim, and backlash at .010 (avg.). This was the first pattern I took before 'moving things around'

However it doesn't matter now :( , new gears will arrive this weekend and I'll start over. Along with a stand as doing this on the counter is no fun...
 

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66BlueGoose

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No real change on the drive side, but coast side is more towards middle. I can see some of the unmarked gears in these new pictures, looks like drive side has been running more towards the toe before the tear down. I use my engine stand, just enough articulation to make it work, feel for you trying to do it on the counter.
 
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tirewater

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No real change on the drive side, but coast side is more towards middle. I can see some of the unmarked gears in these new pictures, looks like drive side has been running more towards the toe before the tear down. I use my engine stand, just enough articulation to make it work, feel for you trying to do it on the counter.

The stand will be handy. I toyed with building a jig, but $40 was worth my time. I used a piece of flat stock bolted to the housing to brace it for torquing the bolts.

I'm more annoyed with the run out on the ring gear. The fit on the carrier was *very* tight and having removed the ring gear already, it left gouges into the carrier that I'll need to file down.

Thanks for the feedback. I'm sure I'll be second guessing the new gears when I get those installed. Lol...
 
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