Rich
I was also intimidated by this task and always just spit up the money to get a pro to do it. I also dealt with "Well I can have it done NEXT WEEK and then NEXT NEXT WEEK and so on and so on. Some of these guys are like body shop guys. They can do good work if they feel like it but they sure don't feel like doing it when promised and there is always the "They all howl a little! BULL S____t.
I was almost always pissed off at the result. To me if the gears are not as quiet as a tomb they are NG. I know that is a little harsh but that is what I expect when I go to someone who is supposed to have done it over and over and over...as in done it for a living.
Finally I said ENOUGH I am not chokin out any more money for labor.....No Mas. I got a dial indicator, a micrometer and a caliper and a press and a pile of GM shims and I read the Overhaul Manual till I could recite it. There really is no black magic here what there is is a job that requires patience and patience is measued at the third digit to the right of the decimal point. If you have that level of patience you can do it.
I have only done a few but I tell you what, they are quiet and they lived. I won't do the work for anyone but me cause I don't wanna hear the crying when some racer type with 13 inch slicks and 500,000 HP blows a perfect rear to Kingdom Come. I know what I am going to heae. It is always something like "You did something wrong you SOB & I want a new rear". Not going there any more than I am going back to get the so called "Pros" to set up my stuff any more.
Ya just have to be willing to take it apart again and again till the pattern is right. Close enough ain't good enough and that is that. If it says .004 to .006 that is what it has to be. Period. None of this racer lore "If it is an automatic with slicks tighten up the backlash" or "If it is a stick with slicks tighten up the backlash". Yes I made that stick and automatic example the same because likely the same advice can be heard from on or another hot shoe weekend racer. I do what the manual says I try to stick with GM gears and I don't do silly things like using a ring gear from one set and a pinion from another because the ratio is one I just gotta have. I change my rear ratio plans to accomodate as much as possible whatever gear set I can find. In the case of that .004 to .006 I would shoot for .005, never mind the extra few thou adjustment cause that is what the guys at the track say. Also if it says measure the backlash at 3 or 4 points around the ring that is what I do. I do it cause the manual says do it.
Another thing before I go. New gears are good gears and used gears are almost always junk as far as quiet running. Once the tooth face has a pattern in it there is almost no way to totally quiet them down. Remember quiet is the number one measure of success for me.
Lastly if at all possible, and I know this is getting harder and harder to do, I will not work with a housing that has been used to set up gears other than the original factory setup. If I see a desert gear ratio virgin rear for sale and the price is righ I will pick it up. That way I know that I am starting out without any number of things that can happen to these rears when the "Close enough for me" set up guys are operating on the gears.
You just cannot tell what those things have been thru what with racing stresses, misinstalled bearing caps, over heating due to incorrect gear set ups. The factory got it right every time and if the rear is unmolested you know it is at worst only carrying some worn bearings as opposed to god knows what butcher work.
