Hey, just swapped out 2.73 for 3.55 in my 12 bolt. These are new summit racing gears. This is the patern on the drive side, the partern on the otherside of the gear is closer to the inside diameter of the gear but i ran out of space to host another picture. The pattern looks pretty centered, but is alittle towards the top of the tooth. Does it look good enough. Also this is with .024 behind the pinion

http://www.chevelles.com/showroom/data/500/medium/IMG_1502.JPG

Whats your backlash like? It looks pretty close to me.

Dave

What's Your backlash?

Are You turning axle or pinion. Need to turn it by the axle.

Not the best pic, but I think You're too shallow. Need to add .004-.005.

Here's a link too a great website. http://www.ringpinion.com/HowTo.aspx

i agree with dave, the pattern is not good yet.
turn the assy by the posi unit, NOT THE PINION.
i would also tell you to add .005 pinion shim.
but 1st, what is the backlash?
tom

backlash is .007, and i was turning it by the carrier, not the pinion. also, i scuffed up the inside of the pinion bearing so that it can slide on snug but doesnt need to be pressed on, is it ok to leave like that.

chris,
ok , knowing the BL. i would add the .005 shim to the pinion. i hope the bearing you scuffed is not the one you want to run. some guys will do that to make it easier to setup and then switch to the new bearing for final setup.
i never do that. the old and new bearing will undoubtably be different thicknesses. therefore setup is different. if you are planning on running that bearing, don't. under load the race will try and slip on the pinion and ruin everything. take your time and use a press. even if you do not own one. find one and use it. tom

I added .004 like suggested, this is at .028 behind the pinion with .007 backlash, looks alittle better to me. One other question, im using a honed out bearing for setting up the patern easily, when i press on a new bearing will it significantly change the patern, ofcourse ill check the patern after i install the new bearnig but am i wasting my time seting it up with the old bearing? anyways let me know how this patern looks to you, thanks

http://www.chevelles.com/showroom/data/500/IMG_1517.JPG

It will be good but check for good measures.

Dave

that pattern is better. can you also post the coast side? can you also put the camera in macro mode or flower for better closeups?
i would suggest using the new unhoned bearing. it will be a different pattern. tom

here is the coast side

http://www.chevelles.com/showroom/data/500/IMG_1519.JPG

i would add another .003 to the pinion and try again. the pattern is too much on the tip of the tooth. tom

Just saw Your PM.

I'll be curious to see what Tom say's, but I start looking for a pattern with .030 under the pinion.

here is the pattern with .030 under the pinion and about .008-.009 backlash, This is now with a new bearing pressed on instead of the old one, along with a new race. It is alittle to the inside of the ring, but at this point it will be very difficult for me to adjust, as i dont have access to a press, to get the new bearing off. Im kinda hoping this is good enough for a street car, and i also assume the new bearing will wear alittle causing the actual pattern to be alittle more shallow.

http://www.chevelles.com/showroom/data/500/IMG_1522.JPG

Can You post a pic of the coast?

It look's much better, just need to see the other side.

i forgot to take a pic of the coast, and have it apart now, im pretty set on using this pattern, and am goin to finish it up tommarow. the coast pattern covered almost all of the gear, top to bottom, side to side with alittle untouched area near the outside of the teeth. looked decent to me though.

that is not a bad looking pattern. to bad you could no post the coast side. you are asking for help and provide only 1/2 of the info needed.
be carefull when torqing the pinion, it takes alot of power to get it done. don't knock the car off the stands. tom