I remember all too well that bad feeling I had w/ repeated problems w/ my gears, glad I could help push you through to getting yours nice and quiet. Seems like you got lucky w/ the tech seeing those pics and giving you some good free advice.

 

No kidding. Talk about luck. Like I said, I'm going to give it a week to see if they quiet even more. I feel like trying the 0.031" shim but the pattern is towards the heel as it is and I don't know if making it more shallow will benefit. I have the backlash set to 0.006" (more on the tight end). I did that because I saw on the ring gear, what looked like 900.0. It dawned on me that I was reading it upside down and it actually said 0.006! Thinking that is what the backlash was set at for lapping. By the way, here's a picture of the 8 year old. Just taken about 3 minutes ago.

 

Hmmm, drove it around for a couple of days and seems that when it warms up, the noise gets a little louder. I may tweak the backlash a tad and see if that helps. Specs for the Motives are 0.008 +/- 0.003 (0.005 to 0.011) and right now I have them set to 0.006 which can be a bit on the tight side, thinking when it warms up, the backlash decreases and noise increases. Thoughts?

 

Truck looks good, and your theory about the gears sounds possible. Get someone to ride along w/ you and see if they notice it getting louder after it's warmed up. It may just be in your head at this point, or you could see if you could spot that tech at the dealer again and get his input.

 

I wouldn't remember who that guy even was, but I'm supposed to head to the dealer in the next few days and that'll give me an excuse to try and see if I can find the guy. Or just ask around for a gear expert. I frequent there a bit, maybe I can squeeze out a ride along or at least a question.

It's just weird, to me anyway, that the gear noise from 45-55MPH is almost nonexistent when I first take off in the morning, then about 10 minutes later, the noise is there, but not nearly as loud as it used to be. Something is "adjusting" during warm up to cause the noise. What ever that might be. Also when it warms up, it's weird but seems like I feel every little bump in the road almost like there's something really tight in there?

I've been measuring (with my ir thermometer) after every trip and temps range (on the gear cover) from 128*F to about 134*F. Before it was above 140*F (going by holding hand trick). This time I can hold my hand on it no problem. So it's at least running cooler, I think.

I'll probably see (if I'm up to it) about dropping the cover and measuring backlash, recheck patterns and go from there. Adjust out the backlash to 0.008 - 0.009, check pattern - test drive. Still noise, then maybe shim down the pinion again but I feel fine giving it a break this weekend.

 

Managed to find the guy at the dealer yesterday, believe it or not! (his name is Ron by the way) I was there dropping off a friend to pick up his Ram and he was right there so I ran up and asked him to kind of help me out. I looked "desperate" for answers and told him that they were my only hope. I got his attention and gave him all of my symptoms. He remembered me from the gear patterns and he had a few minutes so we chatted. I didn't have my truck yesterday, otherwise I'd have him ride along - if he even could have, but anyway.

He seems to think my preload on the pinion isn't right (too low). From the symptoms I gave him, noise on accel at a certain range, then noise on decel at another. He says the depth is probably fine and to check pinion preload. This clicked. I mentioned that the other shop had set all of that so I "assumed" it was right and as long as the pinion "felt" the same when I was done, I would be fine. After I told him it turns a little free after whirling it, he said he doesn't think it's enough. 15 to 35 in/lbs. of force, if you're talking midrange, can feel tight. Although smooth, shouldn't turn free. I also fessed up and told him I took my impact gun to it when tightening it up until it wouldn't turn any more, thinking that was enough. He reminded me that 210 ft/lbs. minimum of force is a lot and to double check that as well as the pinion nut may have worked itself loose.

Backlash and blueing of the axle end. This was most likely the result of the wrong thickness shim being used before, forcing the carrier to be too far one way to achieve correct backlash. He recommended (if the markings on the Motive gear are 0.006) so set it to 0.007 to 0.008 during the trial, and when it tightens up, should get me where I need to be when I tighten everything up. Oh, and to make sure to measure backlash at four locations around the ring gear. Okay, I'll admit, I didn't do this because the shop I took it to said I was at 0.000 variance. Again, assuming that they measured it right, I took their word and just measured one spot.

So the plan for today is, get more beer, set the pinion preload correctly, tighten that pinion nut manually and set backlash between 0.007 and 0.008, measuring four locations and using the location of the least backlash to set. Snug up those adjusters to 75 ft./lbs (he also says that's critical) after seating bearings, tighten the caps and fill 'er up and have a nice day.

Oh, he asked me how long it took me to set backlash, I said probably about 30 minutes and that I tightened the adjusters as good as I could and that they didn't feel tight when I loosened them the first time. "Doesn't matter." It's in the book for a reason. And it may take a couple of hours to get it right if you're not familiar with these rears. There was a whole detailed speel about how to set it and it's all in the manual.

So bottom line, my fault for a.) taking shop's word everything was set right and b.) thinking that not measuring everything and going by "feel" would actually work. Now, not to say the shop did anything wrong, yet ... that has yet to be seen and hopefully, will be able to post some good results later on (pending weather - it's crappy drizzly today).

There's my confession. Now time to get to work. And if I can't get it right, I'll suck it up and take it there. He said just to have him check out the rear axle, don't mention the third party ring and pinion that's in there.

 

Oh and I need to get it right this weekend! I'm to tow my travel trailer down the street to friend's "farm" house for a President's Day weekend "spectacular!" There'll be like 8 RVs in his yard, Christmas tree bonfires, BBQ, BEER, ATVing, the works! It's only about 10 miles away so hoping it'll be fine. I'm already at 500 miles on the new gears (or close to it) by now.

 

And if it's not right, I'll just tow it with his Chevy :P

 

Damn, well seems like it keeps getting more complicated. Another lesson learned, sometimes the dealer is the best route for these things. Hope you can get it sorted yourself w/o spending too much more on it.

 

I think it's partially due to the fact that I'm pretty ****. Shouldn't take too long to accomplish. Just need the rain to stop.