Gear set-up problem

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Dec 10, 2004 | 05:58 AM

wyldstallyn73

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Gear set-up problem

I am currently TRYING to set up a set of gears and a detroit locker in a dana 70 front axle. The axle was an industrial/commercial surplus unit that I widened out- it never was ran or even had gear oil in it, and I am using the 5.89 gears that came in it. I figured all I would have to do is mess with the carrier bearing shims, as the pinion setting wouldnt be an issue. Basically, I cant get the pinion to move away from the carrier far enough to get the desired pattern. I have removed all of the shims from behind the inner pinion bearing and the oil slinger to get the pinion gear to sink further into the bearing and it's still not enough!! Right now I am "surfacing" the inner pinion bearing race on the backside, which will also move the pinion away from carrier when assembled. I will hopefully get to try some more assembly time this weekend, but has anybody run into this before???? Am I overlooking something???

Dec 10, 2004 | 08:39 AM

holland501

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From: houston

This is just an idea, so don't get crazy people. When you get into the real high ratios, the gear teeth start to get smaller compaired to say 3:55, 3:73 or even 4:10. Smaller teeth means weaker teeth. Setting the pinion DEEP in the ring gear gives more contact area close to the base. This decreases the chance of breakage. Possibily the gear manufacturer took this into consideration when making the gear set. Drag racer set gears this way so the extreem shock load doesn't break teeth. It does make for a noisy rearend, but they don't care. Again, just a thought. Good luck.

Dec 11, 2004 | 05:25 AM

wyldstallyn73

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I saw that on an old set of instructions that I dug out- They called it a competition pattern. This rig will never see any pavement action unless its a parade (but not a gay pride parade) So I wont have the chance of a high speed failure to contend with. And I also have a line on some more sets of gears from the same source. Just didnt know if this happened on a "regular" basis or what!!

Dec 12, 2004 | 01:36 AM

wyldstallyn73

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Got it figured out if anybody cares- Seems that I had my brain working backwards in relation to what I was trying to do!!! While I'm not a gear setup guru (obviously!!!), I have done enough that I should know better- especially for the length of time I was fighting with it. About a week!!!!

Dec 16, 2004 | 11:15 AM

bjorn773

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I'm trying to replace a broken side gear in my 9" carrier. I can't remember what to use to check the gear contact pattern. It's been a long time since I did any gear swaps. Seems like we used some type of marker or something on the ring gears, then spun it to check the pattern. What do you recommend? Also, any good tech articles on proper contact pattern would help me immensely.

Dec 16, 2004 | 11:28 AM

bjorn773

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Sorry, I should have looked for the tech article before asking about the pattern procedure. I do still need to know where to buy the grease/paint for checking the pattern. Your recommendation will be appreciated, thanks in advance!

Dec 17, 2004 | 05:12 AM

wyldstallyn73

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I have used machinist dye (prussian blue) with good results. In a previous post I asked if anyone knew why this might be a bad idea, because I don't believe I have heard of anybody else using it- the idea just kind of came to me one day. Nobody replied with any negative responses, but someone said you can get the regular gear marking compound at any GM dealership- just don't let anybody you know see you there!!! If you havent messed with your pinion, you shouldnt need to look for a pattern when you reassemble, just your backlash.