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Opinions on this gear contact pattern

Posted By: RV2

Opinions on this gear contact pattern - 02/13/18 01:04 AM

This is a Dana 60 with new 4:10 gears and all new bearings

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Posted By: RV2

Re: Opinions on this gear contact pattern - 02/13/18 01:06 AM

2

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Posted By: CMcAllister

Re: Opinions on this gear contact pattern - 02/13/18 01:32 AM

It's unusual to see the entire face of the tooth wiped clean like that. I'd want to see one of the other teeth where the marking compound on the pinion was transferred to the ring gear.
Posted By: fourgearsavoy

Re: Opinions on this gear contact pattern - 02/13/18 04:17 AM

Yeah you usually see that type of pattern with used gears shruggy
Maybe the Doctor will chime in for an opinion bow

Gus beer
Posted By: J_BODY

Re: Opinions on this gear contact pattern - 02/13/18 05:59 AM

Like others, I haven't encountered a pattern like this. In searching images they show a "full length pattern" as being acceptable. The 4.30s in my present S60 were used and it did take me many times of trial and error to get a drive pattern that I was "ok" with.
Posted By: 4406bbl

Re: Opinions on this gear contact pattern - 02/13/18 06:47 AM

Last set of motive brand gears I had looked kinda like that, put more shim in and it helped, ultimately I bought spicer gears and they patterned perfect.
Posted By: jwb123

Re: Opinions on this gear contact pattern - 02/13/18 04:01 PM

At first look I would say its a used set of gears, but since they are new, that is not an option. I have been setting up gear sets for 40 years and the last ten with Chinese sets flooding in, the patterns just don't look like they used too. I would as mentioned look at the marking on the pinion to see if contact is in middle of the teeth. The backlash looks good on your pictures, but since it covers the whole tooth you can not tell pinion depth. I purchased a pinon depth tool and if it measures right and the backlash is right with a dial indicator, I don't worry as much any more about the contact pattern. It also matters if the gear set is a hunting or non hunting type, as well as if the gears were hobbed or face milled when manufactured.
http://www.shoptalkforums.com/viewtopic.php?t=145363
thread about the differences.
Posted By: CMcAllister

Re: Opinions on this gear contact pattern - 02/13/18 08:07 PM

You can look at them and tell they aren't used by the finish. They also have very little helix so I assume they are a performance gear and I would expect a little bit of noise. When I mentioned looking at the other teeth, I was talking about the other teeth on the ring gear. As you rotate the gear set, it transfers marking compound to the pinion which, in turn, transfers it bock onto clean teeth on the ring gear. Look at that and see if it indicates what the contact area looks like.

You could also run the pinion in and/or out .006 or so and see if it runs the pattern up or down. You may have hit the depth right where it wants to be.

Used gears are a pain, especially if they aren't going back into the same unit they came out of. Once the backlash opens up, they're junk and not worth fooling with. I will on occasion use an economy gear on a mild application, but I will not use a Chinese gear.
Posted By: dthemi

Re: Opinions on this gear contact pattern - 02/14/18 01:15 AM

Well, I'll chime in too lol.

Personally if it's a pro gear, run it. It'll take a set after a few hits anyway. The pro gear material bends without breaking, and stays there usually.

Trying for perfection, I'd shallow up the pinion (pull out) a few thou, get lash back to .007 and see.

I don't think it's wiping totally across, it looks like the marking compound is too thin in consistency, and lifting it off where the gears are really close but not touching. a grease pencil works better for me than the oily stuff.

Do you have a good load/drag on it when you're checking it?
Posted By: CMcAllister

Re: Opinions on this gear contact pattern - 02/14/18 01:26 AM

Looks like he had the stuff glopped on there pretty thick to me. I like to just use a thin schmear. I'd also like to know the brand on that gear set. Where did he get off to?
Posted By: RV2

Re: Opinions on this gear contact pattern - 02/14/18 03:01 AM

Sorry guys, I haven't had a chance to reply but I also haven't touched it since.
It's a Dana brand gear set.
The paste was thick and oily, I'll wipe it down and try something else.

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