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Discussion Starter · #1 ·
I have printed and read most of the web pages regarding installation of Pinion and 3rd member. But I still am having trouble figuring out how to make the measurements. Where do you measure the pinion? From where to where, and them setting the backlash, what do you measure? Is a Dial Indicator neccessary, or can you use the Puersian Blue indicator to get a pretty good measurment? I have been talking with various people and the stories are never the same. Two of the people say I don't need a dial indicator, just the Puersian blue to get a good matching of the teeth.

Thanks

J just
E mpty
E very
P ocket!!
 

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i work with a guy thats been setting up ring and pinions for over 20 years and he uses a dial indicator everytime (he can guess pretty close but pretty close is not good enough if you want your gears to last)
the pinion depth is measures from the center line of the the diff. housing, then depending on how your set of gears are machined is if you will need to set the depth in/out acouple thousands, (Dana gears alway have this etched on the pinion itself)

checking backlash: the amout of slop (freeplay) between the teeth on the pinion and the ring gear, it checked with the pinion properly set and held still (not rotating) then you turn the ring gear back and forth measure the rotation on the tip of the teeth at a 90 degree angle, different axles have a different limits usually something like .010 to .016 thousands.

of course this just get you close, then you need some gear marking compound to see how the pattern on both sides of the gear are.
good luck

3/4tonYJ
My Jeep Page
 
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Discussion Starter · #3 ·
Typical backlash is .004-009. Make sure you check it at several places on the ring gear due to runout, then get a good average.
Too large a backlash will result in broken teeth. Get a GOOD dial indicator with a magnetic stand. If you are not going to be
doing this again and again I suggest you pay to have it done. My dial indicator cost a couple hundred bucks may years ago and
my magnetic stand was about 75 bucks, a big investment. You will also need a micrometer to measure carrier bearing spacers,
a decent one of those will run you about another 75 bucks.

Brad
ORC Land Use Section Editor
http://www.off-road.com/land
 
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Discussion Starter · #4 ·
You, obviously, can get about as many different answers as you want. I have been using a pinion depth-setting gauge, and a dial indicator. But, I have listened to, and watched, one of the set-up guys at Tri-County Gear (Pomona, ca), and this person used nothing but his 'pattern-compound'. His feeling is, that using the gauges, only get you 'close'. He never uses the gauges for the final pattern. On-the-other-hand, I've had pretty good luck, using the gauges. I often get a good pattern on the first try.
No matter what you do, my advise is to not try this without 'set-up' bearings. Tri-County uses them, Hick's uses them (and, me-too). In my view, you will just frustrate yourself, if you try to do the job without them. (Some of the gear parts sources even loan these bearings. But, no problem to make your own.)
To address your question about setting pinion depth, using common machinists tools... I have done this, and it works fine. The point is, the pinion depth is from the center-line of the ring gear/ carrier, to the machined-face of the pinion. Use some ingenuity to figure this out. You need any machinists depth measuring devise. The cover surface is machined, and you need to assume it is 'square' with the pinion. Put the carrier caps on, no bearings, and measure to the nearest bearing surface, farthest bearing surface, and the pinion surface. Do the math, and you will have the pinion depth. Target depth numbers come with the gears, and the variance is etched on the pinion (like, .001, .002, etc.) So, for a 30, the pinion depth target could be 2.252 (2.250 nominal, .002 etched on pinion). Or, for a 44, the nominal is 2.625, add the variance, and you could have a target of 2.627, or whatever.
A picture of this, and instructions, comes with new, major-brand, gears.
Bottom line... This is in the instructions, too..... The final pattern is what counts. And, all the measuring can either help you, or not help you.
An experienced person, with set-up bearings and compound, can do this in about a half-hour-to-45 minutes. Most 'newbies', would spend a whole day, and still not have any confidence that it is 'right'.
Good luck.

bobH
 
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Discussion Starter · #5 ·
if your on here asking how and what,take it in to someone,my father is an instrument maker and machinist,he
passed down alot over the years,learning how to set up gears wasn't something you get told how and gung ho
in a day.good luck

 
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Discussion Starter · #6 ·
Decided that after I couldn't get the Axle out of the housing, that I am going to take it to someone to set-up. I don't have a press and it soulds like you really need one to bress bearings on and off. I took it to a guy that only wanted $150 to take the axle apart, press on the pinion bearings and the carrier berings, and finally set up the gears. I suppose since it was the rear, that you use all the time it would be better to have him do it.

J just
E mpty
E very
P ocket!!
 
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