Bengtson95

I'm rebuilding the 10 bolt and I'm getting runout but I'm talking runout on the diameter of the gear...the back face is within spec but when I rotate I get tight spots. 001 backlash, up to .014 at 180 degrees. I measured the runout along the diameter and am getting .014 runout. So say at 3 oclock the ring gear is tight, 9 o'clock is loose, but 6 and 12 are both perfect at .0075 backlash, I let QP know and they called me back and recommended I deburr the ring gear and mount it 90 degrees from where it's at now. What do you guys think is the problem? Also I was able to correct the runout within .002 with the ring gear bolts snugged then when I torque it down the runout comes back. My theory is the bolt pattern is slightly off or maybe one hole is not straight?

FirstYrLS1Z

iTrader: (4)

Ring gear is a slip fit/slightly snug slip fit onto the carrier, was it ?
I've had your problem a couple times.
One time is was cured be taking a flat stone(the type used for knife sharpening) and cleaning any burrs/high spots on the carrier flange surface that the ring gear mates to and 'stoning' the ring gear surface that mounts to that flange.
Another time I measured the run-out of the carrier (without the ring gear) (with the carrier bearing shims and caps torqued) , carrier wasn't running true and had to be scrapped. If the carrier won't run true, ring gear on it won't run true. The carriers' ends that the bearings are pressed onto (I'll call them tube ends) can become stressed beyond useable and create a 'wobble'.
Why was it necessary to rebuild,what happened to it ?

Bengtson95

the carrier does run true. And I did stone the mating surfaces. I will do it again and clock the gear to verify again today. And I'm rebuilding because about 2k miles after I put 4.10s in the ring gear bolts backed out and one broke off and went through the diff cover. I checked for damage and I couldn't find anything but a few dings.. I am using a spacer (series 2 carrier series 3 gears) but if anything it's a loose fit not a slip fit in that locating diameter on the carrier.. I just find it odd the runout happens when I torque it down and not when its snugged up

FirstYrLS1Z

iTrader: (4)

You provided more info as far as what you're using.
A spacer, did you stone the spacer ? And then 'mic' it in many places ? I find many spacers are not flat and parallel. There are quite a few threads advising against using a spacer.
2 series carrier with 4.10s'. Is the car an automatic,because of the 2 series carrier ? Or was it a 3 series carrier car that the original was replaced with a 2 series ?

Bengtson95

Drive side

Drive side

Coast, couldnt get much better pic, the marking is swiped pretty much in the center of the tooth
Update* I took the carrier apart and re stoned all surfaces. Including the spacer. Then reassembled and its within .001 runout! Now I have it together and I have a variance between .0045-.010 backlash. It's weird, I am checking at 3, 6, 9, and 12 o clock and every revolution my values change. I assume because the ring gear is mating with different teeth on each revolution. But I looked up specs and the tightest tolerance I found was .004 and the loosest was .012...so I am assuming it will have to do, considering if I make it looser it'll b too loose on one side and vise versa. I ran a pattern and I think it's good. I will attach some a plus photos for you guys to look at as I'm not 100% sure it's good.

Bengtson95

yeah I didnt want to use a spacer but i was dead set on 3.90s and couldnt find series 2. Car was originally an auto with 2.73s. Has 70k miles and the posi is still strong.

Bengtson95

Also here's the housing. Powder coat adds horsepower I heard

01ssreda4

iTrader: (96)

The worst variance i have ever seen in backlash was like .006-.010-.006 in a circle. It was a 12 bolt and i let it go out the door like that. It never came back (was a buddys car). Most vary about .001.

Bengtson95

Well I'm not sure why mine varies so much, I must have pinion runout? Ring gear axial runout and radial runout are good. Unless my Richmond excel gear set sucks...it was cheaper than most

cam

iTrader: (9)

Something is not right there bud. Thats WAYYYY too much runout imo. I like to see 0.0002 or less. Even 0.0004" will usually make an oscillating noise at cruise speed which can be super annoying. You sure theres no hard loktite gooped up in the holes on the ring gear? No burrs anywhere? I dont use a stone for facing I have a HUGE 2.5" w x 14" long single cut file that I use for facing. Easy to find the high spots with such a file and in your case probably well worth it. Black Diamond, file btw, dont be cheap with files buy a good one, take care of it, lasts a loooooooong time.

Bengtson95

well I dont have any runout anymore. Maybe u misread my backlash readings. I have .0005 runout in the ring gear, which is definitely good, and thats after thoroughly stoning all mating surfaces. A file makes quick work but a gentle long stoning is better

cam

iTrader: (9)

Musta misread. File is risky due to operator error, but much flatter and trues surfaces perfectly if your careful. Glad you got it sorted you are correct I did not see your updated numbers under the pics

Bengtson95

Do you think that pattern is good? Also should I be concerned with the backlash varience?

cam

iTrader: (9)

I'd work the pinion depth on that and see if it fares better. Am I reading correctly that your backlash is varied from 0.0045 - 0.0010?? Thats not right, somethings up. Patterns can be witchy processes to play with so I typically start with the stock shim, add 5 thou and test, subtract 5 from stock and test and compare patterns and work from there. This vid might prove helpful for you

Bengtson95

informative video, thanks. And yeah I'm getting .0055 variation in backlash. Between .0045 to .010. Going by that video it looks like my drive is good but my coast is slightly far out. So the pinion needs to come towards the gear?

cam

iTrader: (9)

You want the contact as centered on the tooth as possible. Not rolling off the top or buried into the root. Looks like your into deep captain, take 5 or ten thou off the pinion shim and see how it goes. If you dont have a set up bearing I highly recommend one. Easy to make with a flap abrasive wheel 60 grit or so run through a new bearing until it JUST slides over the pinion, dont take off too much it must stay concentric

Bengtson95

I did make a setup bearing and took several pinion depth readings, got it right in the money with what was scribed on the pinion and then when I pressed the new one on it sat about .005 lower.

cam

iTrader: (9)

As I said, witchy. These things can be a bear to dial in especially the torque arm diffs because the pumpkin is getting torqued all over the place, age, bumps hits all play a part. Best is to be sure the contact is nicely centered on the tooth which yours is not yet there. i'd start by adjusting pinion shim, set backlash the same as now, compare patterns. This way you can see where your winning and losing and add/subtract accordingly.

Bengtson95

Yeah these are pretty annoying. Although in that video u posted the guy said u want the pattern to sit in towards to root so as torque is applied it spreads along the tooth

cam

iTrader: (9)

Get the pattern centered on the tooth is the most critical to strength, if you can get it perfectly centered you could try and aim for a competition pattern which is basically what hes talking about