Setting backlash, ford 9"

Hi guys! As some of you know, last week my 9" rear end grenaded on me, so im going to set up my other third member now.

The pinion i have set up already with a solid sleeve and shims.

I found a guy in town who could do the rest of the job for about 240 dollars.  :huh:

So i went and bought a dial indicator and some marking grease instead, int cant be that hard right? I also made a tool for the adjuster nuts. 

So, if someone could be nice enough to guide me through this process. 

Backlash, is that the amount of movement the ring gear has before engaging the pinion or what?

Im lost, appreciate help.

Yes, backlash is how far the ring gear moves back and forth between the pinion gear teeth, with the pinion prevented from moving. Check it in several places.

https://www.7173mustangs.com/thread-swapping-rear-gears

Above is your old thread.

1) Is your pinion preload set correctly? (numbers vary depending on what resource you look at , but with new bearings about 15 inch pounds, used about 8 inch pounds). Not sure how you are going to check this since a dial type 0-30 or 0-75 inch pound torque wrench is not on your tool list.

Once pinion preload is correct you play with pinion depth and backlash to get your pattern correct.  Once you find a shim stack for the pinion assembly that gives you a nice pattern while your backlash is within specification you are good to go.  Keep it in mind that your carrier bearings need a bit of preload too, so adjust the nuts so there is a slight amount of drag (which you would measure with a dial type torque wrench if you had one).

Backlash is the distance in thousands of an inch that you can rotate the ring gear back and fourth before it makes contact with opposite sides of the pinion gear teeth.  Measure it with a dial indicator on the outmost edge of a tooth.  You should check all four quadrants (check, then turn it 90 degrees, repeat 3 times). All 4 places you measure should be within your backlash spec.

I wish videos (and computers and internet) like that were available when I started doing this stuff, it would have been easier than reading through repair manuals, scratching my head (no wonder I'm bald) wondering just what they meant and what they were referring to in the low resolution illustrations. Plus, I wouldn't have boxes of manuals and books that just take up space, but because I'm a packrat at heart refuse to get rid of.

Apparently i had the dial type torque wrench at work, so that sorted out good.

Thanks guys, i have everything i neef!

Man this is killing me, i have fiddled around for almost two hours now and im still not there. The hard part is getting within the backlash specs in all 4 corners  :shootself:

Also the gear marking compound i got sucks...

Im here right now (attached)

What do you think? More shims to the pinion housing?

Seen worse. Are these new gears or used?

That gear marking compound does suck!

Try getting some GM 1052351 marking compound or even try yellow oil paint (for oil painting on canvas).  Paint in on 3 or 4 teeth both sides and see what it looks like.  Use a disposable "flux" brush

That pattern is so undefined because of the compound it is hard to see what is going on.

Here are some close up shots of gears I have set up.  I like to get the pattern about centered between the crown and the root of the tooth, and go more towards the toe (inside of the gear) than the heel.  The pattern will creep out more towards the center of the tooth under load.  These are all new gears, so the patches are pretty small.  I have seen much larger contact patterns on used gears.

The 14 bolt is a more centered pattern.  I was able to get my foot on the parking brake cable and apply plenty of resistance while turning the pinion with a large ratchet.  

10.5" AAM / GM Corporate 14 Bolt



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10.5" AAM / GM Corporate 14 Bolt



Dana 60 Front Axle



Closeup of the Dana 60



Not sure if this was my Dana 60 or a Dana 44 I did.



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These are new gears.

I cant seem to find any marking compound, thats the problem. This is some DIY compound that i did following a guide online, but its rubbish.

Is there anything else that would work sort of good? Better than this at least?

Is Amazon.com an option?

https://www.amazon.com/gp/aw/d/B00BK7MFC8/ref=mp_s_a_1_1?ie=UTF8&qid=1499952234&sr=8-1&pi=AC_SX236_SY340_FMwebp_QL65&keywords=1052351&dpPl=1&dpID=31x0RfZN71L&ref=plSrch

Try calling around to any auto parts stores that specialize in racing . Worst case if there is a GM dealership you should be able to give them that part number and pay some crazy amount of money for gear marking compound.

I have never tried it but worst case you could go to an art place and get some cadmium yellow dark or cadmium yellow deep colored oil paint and see how that works

An option to the yellow marking compound is Prussian Blue. It may be more available, as it is used for more than just gear marking. I've used it for many years, not quite as much contrast as the yellow stuff, but close, and certainly better that what you're using.

https://www.napaonline.com/en/p/BK_80038

Apparently, lipstick did the trick  

When you actually could see where you were at, it was soo much easier. Took about an hour to get it perfect.

So its going back in the car tonight, after cleaning out the axle of metal debris.

And tomorrow the car will probably be picked up by a buyer, money is tight right now and i need a cheaper cruiser. And also i have to replace the engine in one of my daily drivers.

I really cant thank everyone enough for all the help ive gotten on this forum, by far the friendliest, most helpful forum ive ever been too.

I will probably still hang around here though