vortec350s10

Here are a couple videos of how it currently sounds. The first one is up on jack stands and it's a lot louder than while driving.


http://s116.photobucket.com/user/ryg...c07b3.mp4.html


http://s116.photobucket.com/user/ryg...02987.mp4.html

skinny z

I've attempted to rebuild my Dana 44 a couple of times and ended up with what I thought was gear noise AND bearing noise. First time through I ate a pinion bearing. The noise became progessively worse over time until it was basically undriveable. It was easy to tell something was seriously messed up. Not sure why that happened as I followed all the guidelines for setting up pre-load and such. That was on top of what was obviously gear whine as that noise changed significanltly from drive to coast. This time around I took it to a pro (4 x 4 specialist no less). End result was another noisy set of gears and what I thought was more bearing noise. Very intense from approching 40 mph to past 55 or so. My builder was under the car listening, checked for temps, etc etc. (on stands I'll point out) While he's oblidged to rebuild it again (hence going to pro) he said it in the meantinme I can take it on the 6000 mile road trip I had planned and could beat on it at the track all I wanted. His says it's not a bearing deal but something in his setup.
With any luck you'll be able to do the same.

vortec350s10

Wow yeah that's the benefit of having someone else build it. I will probably do it again myself because that's just how I am. There's nothing more frustrating than not understanding what caused the problem. If I tear it apart and realize, oh hey look -the adjuster somehow backed off or oh jeez that carrier bearing cap somehow came loose I at least would feel better. When I tear into it, I hope it's apparent so I can learn from it and not make the same mistake again.

I decided to drive it to work today just to put some miles on it with it noisy just to see if it would worsen. It doesn't seem to be. Temps stayed normal as well. I'll be taking it to the track tomorrow and thrashing on it at 10 psi so hopefully no more surprises.

big gear head

I did a 9 inch a few weeks ago. It had just been built by someone else with new Motive 3.25 gears and new bearings. It made so much noise that you could barely talk inside the car. I took it apart and checked the pattern, backlash and bearings and I couldn't find anything wrong. The pattern looked great and if I had built it I would have been happy with the way everything looked. I was told to go ahead and build it again with new parts, so I did. When they brought me the new parts the gear was exactly the same as the one I took out of it. I didn't think it would be any better when I finished it, but when they drove the car it was completely quiet. I have no idea why it was making so much noise before.

vortec350s10

That's interesting. Well hearing that eases my concerns a little. I wonder if the noise on that rear you rebuilt was loud from day 1 or if it developed later.
That's the only thing I'm confused with on mine, going from silent to noisy as soon as I bet on it with slicks. Well for now it's hammer down, fingers crossed!

big gear head

It made noise from the beginning.

TZFBird

You bought the long pinion yoke instead of the short. There is a 1" length difference between them.

When you hammer on it, it compresses the suspension enough to wedge the driveshaft between the transmission output shaft and the differential. This throws off the backlash by a couple thousandths and causes the noise.

big gear head

Nope, I'm pretty sure that's the short yoke.

vortec350s10

I should have the short yoke, I chose that one in case I would ever want to run my old driveshaft. I read the distance would be very close to stock. Which it is.

And my driveshaft is the correct length. There is about 1" of additional compression that can occur with my suspension at ride height.

I did end up pulling the pinion out and there is wear on both gears, with some "heat marks" or something on the pinion teeth where certain parts are darker than the rest. It looked like (judging by the pinion tooth wear pattern) that the pinion needed to be deeper. I removed .003" of shim from the pinion and slapped it back together. It is significantly quieter now. Almost silent at certain speeds. There was more very fine metal particles in the oil, so I'm not convinced it's "fixed" but this is how I'm running it for now. This weekend I'll be running a road coarse and drag strip pretty hard so we'll see how she goes.

TZFBird

Well better to suggest it and be wrong than not and never know. I'm out of ideas then. Good luck and set it up right this time.

vortec350s10

Thanks, I appreciate the ideas. No doubt we are all in here to help each other.

vortec350s10

Well back to the drawing board again. Last weekend I ran the car hard on the road course along with driving it 2hrs to the track and back. The second day it started getting much louder and the way home was so bad there were people walking down the sidewalk looking at me funny as I drove by. Drained the oil tonight and it looked like charcoal metallic paint mixed with the yellow colored oil. I'll be ordering all new bearings and a gear set again. I'm hoping my tapered roller axle bearings are ok as they are a bitch to press on and off. I still have to figure out why this is happening. I'm gonna try a different oil and avoid back to back launches with the slicks.

DIGGLER

iTrader: (1)

it sounds like something is moving around....
who made the aluminum pinion support?
when you pressed the pinion bearing races into the support did you heat it first?
did the pinion still have some bearing preload on it when you had it out?

i dont think the launches you are doing would make this rearend break a sweat. its something more internal going on.

big gear head

Yea, this has me confused too. The pattern on both gears looked very good and as long as the bearing preload was correct it should have been fine for many years.

vortec350s10

When I removed the pinion assembly before the road course weekend I was hoping to find that the pinion bearings had lost their preload but they still had preload and it spun smoothly just as when I first set it up.

The bearing support is an aluminum one off eBay, it seems well made and has the oil ports machined into it so both bearings should be lubed well.
Here's the support.
http://www.ebay.com/itm/371101133965

The first time I installed the races I heated it up with a heat gun and chilled the races in the freezer. I used an arbor press and they fit pretty tightly. The second set of bearings I did at home and I was able to work them out and install the new ones with no heat and just a punch and hammer working around them little by little.
I hope to have the third member out today and I'll take some more photos of the gears. Just by spinning the yoke it feels like the backlash has increased significantly from how it's suppose to be.
But yeah this has me confused still as to what is happening. To me it just seems like the gears themselves are overheating and just grinding themselves up as they mesh.
R
Thanks for sticking with me guys, I'll let you know when it's out and if I find anything odd.

big gear head

Can you take the gears to a machine shop and have the hardness checked? They should be somewhere around 58 to 60 Rockwell C. If they are soft then that is where the problem is. I ran into that once with a Richmond gear. The heat treat process didn't go right and the gears were about 42 Rockwell C.

vortec350s10

Yeah I do have a friend that works at a pretty badass machine shop. I'll ask him if they have that capability.

vortec350s10

Well I've got it torn out of the housing, I hope my axle bearings are ok since there is a decent amount of metallic in the oil sitting in the bottom of the axle tubes.



Here's how the teeth look. There are burrs on both ends of the teeth, and the drive side of the teeth looks like it's been wearing away just like the last time with my used Ford gears.










If I run the tip of a screwdriver across the surface, it's definitely rough. The coast side is much smoother. I'm going to measure the backlash before I pull the pinion, it feels like a lot.

TTOP350

iTrader: (8)

Its almost like the case or pinion support aren't machined properly???

The way the pinion is digging into base of the rings drive side and chewing off the top of the coast side, something is out of wack.
Like the front of the pinion is pointed to the driver side or the carrier is cocked to the passside.

I've never seen anything like that.

big gear head

You got me stumped. They should have been great with the pattern that you had when you set them up. This should have lasted for many years with no problems. Did you use the same oil both times? Did you put anything in the oil? Grease?

TTOP350

iTrader: (8)

Looked great to me also!!!

skinny z

How do you break in your new gear sets? Do you follow the heat/cool procedures? It looks to me that things are just getting too hot for too long . Say goodbye to whatever hardness there is.
You may have covered that already but I had to ask.

vortec350s10

I tore most of it apart today. Checked backlash and it was a whopping .045". Ha, so yeah there is a lot of metal missing. The teeth on the pinion have a big ledge worn in where the edge of the mesh is. Same on the ring gear drive side.

There is some bearing preload left on the pinion, but it's pretty loose, like maybe 5 in lb, can't read low enough on my click style torque wrench. But definitely not fully loose.
How much clearance should there be between the nose of the pinion and the pilot bearing? It fits very loosely and spinning the pinion by hand the pilot bearing doesn't always turn the roller bearings. I'm assuming the pilot bearing is just there for support under heavier load?

Checked the runout on the back of the ring gear before removing the carrier - it had .0015" max. Carrier bearings still had preload. They are kinda rough now, if you spin the carrier fast with preload backed off it makes a hissing sound. Definitely doing all new bearings this time.
I keep going back to thinking about the cheap Orielly Master Pro brand 80-90 non synthetic oil I've always been using. I have it in my truck with no issues but of course it's been fully broken in 200k ago.

vortec350s10

No grease in the oil, same oil as always. I made sure I tightened up the left adjuster last so it cant have any slop to allow the carrier to shift. Everything torqued to spec, and it was all tight and secure when I busted all the bolts loose to disassemble.

vortec350s10

Up around post #45 I described most of it. Am I doing something wrong? This gear set was good and quiet until my 8th 0-60 boost launch of the day. Probably 500 miles with progressively getting harder on it until the day I put the drag radials on and she went from silent to howling pretty quickly.

skinny z

Can't say for certain but my rebuilder, Yukon Gear and Randy's Ring and Pinion (which is were I lifted this from) all say the same thing.

After driving the first 15 to 20 miles, stop and let the differential cool before proceeding. Keep the vehicle at speeds below 60 mph for the first 100 miles. I also recommend putting at least 500 miles on the new gear set before heavy use or towing. During the first 45 miles of towing, it helps to go about 15 miles at a time before stopping to let the differential cool for 15 minutes before continuing. This is necessary because not all of the gear tooth is making contact until it is heavily loaded. When towing, the teeth flex to contact completely, and cause the previously unloaded portion of the teeth to touch and work harden. It is very easy to damage the ring & pinion by overloading before the teeth are broken-in. If you take it easy on a new ring & pinion and keep it full of high quality oil, it will last a lot longer.

Makes perfect sense to me too. Especially if you compare the towing to racing.
Further to that, my rebuilder suggested several cycles of heat/cool. Each progessively longer than the last with sufficient time to drop the temps before proceeding. All in all I did 3 or 4 decent cycles and then changed the oil within the first 400-500 miles.
THEN I stood on it.

vortec350s10

Yep I read this very same thing. I basically did all of that, changed the oil around 300-400 miles, and kept my trips short and drove easy. All was fine until I went to the next level and swapped to my stickier tires. I would imagine all it would take is one time getting the teeth too hot and then there is no going back. I'm still leaning towards that scenario, since I can't really find fault anywhere else.
It's funny there are a few car guys I work with who threw in pre-assembled 9" rears in their old muscle cars and claim they never worried or thought about break-in and theirs are all fine. They think I'm crazy for being so **** about breaking in gears even though perhaps I jumped the gun and got a little over excited when I finally put the slicks back on. Well I'll find out soon how round 3 holds up.
Now I just need to figure out what I can make with all these gears I'm accumulating!

splitty

Man you have way more patience than I do sir. I am buying mine pre assembled after reading this. My buddy builds them and told me I could handle it, I don't need to pay him to do it.. I'm here to tell you I would not be handling this as well as you are. Good luck with round three. I am hoping it works out for you.

vortec350s10

Hey thanks. Yeah luckily it hasn't caused me to miss out on any big car events this year or I'd be taking it much worse. Even though I am not certain it's the break-in or lack of that is causing me these issues, I hope whoever reads my story at least takes it into heavy consideration.

Round 3 parts just arrived. This time I'm running a Yukon gear set, and all new bearings. I'm going to try a different brand non-synthetic oil for break-in this time and I'm not putting the slicks on until next season where hopefully I'll have more milage on it. And when I do put the slicks on, I will avoid back to back pulls to not let the teeth reach any critical temps. Fingers crossed. Ugh, now the chore of cleaning out the housing again and cutting bearings off the Tru Trac. Yay.

skinny z

I don't it's so much the gears getting too hot as it is the oil. Once it reaches a certain temperature it's breaks down and is no longer able to do it's job. At least that's my understanding. I'm not too sure if it actually recovers once it's been "boiled". That may explain a lot if it doesn't.
As for the slicks, I think it can be said that even with a properly broken in gear set, once you start putting the additional stresses of a hard launch to them , you'll be getting deeper into the contact patch. Fresh areas of tooth material will have to go through the work hardening process much like towing as was discussed earlier.
What brand of gear set did you say you ran in the first two iterations?
Good luck with number three.

vortec350s10

Well I'm setting up the Yukon gears now. I'm sort of confused on the pattern though this time. I started with .022 shim for pinion depth, and have been working my way down to .015". It seems like the coast side looks best around .018-.020" but the drive side wants less shim. Which side should I focus the most on? I'm thinking drive side would be more important but I want some expert opinions.

My other setups worked out to have around .020 and .018 I believe. Is it common for gears to require less than .015" shims to compensate for machining tolerances? Below are some pics of the patterns in order from .022 to .015". Backlash on all is between .006 and .009". Thanks guys for input.

.022"





.020"




.018"




.017"





.015"

big gear head

Put the .018 in it and open up the backlash to about .010 to .012 and see how it looks. Yukon gears sometimes like more backlash. I think they usually call for .010 to .014.

vortec350s10

Ok thanks, I'll give that a try.

vortec350s10

Well I opened up the backlash to .012 and put the .018 shim back in. Here's how it looked.





Just for kicks I tried the .010 shim to bring it in way deep just to see how it looked. It didn't seem to affect the drive side much but the coast side shows it's too deep.





I put the .019 (actually not .018 like I first measured) back in and brought the backlash back to .007 and I think this looks like the best combination. What do you think? I can't seem to get as good a pattern as with the Motives no matter what I try.
Here's the .019 with .007 back lash. It seems the tighter backlash moves it closer to the toe end which helps center it.

big gear head

Yea, that last one looks better.

vortec350s10

I think I'm going to try moving the pinion in .002 deeper and maybe that'll be the final setup. Right now it looks like it's touching right to the top of the teeth on the drive side. Ideally there would be a little margin on top that's not touched, right?

big gear head

It does look like it's hitting a little hard at the edge. I think you know what you are doing at this point. It's easier for you to read the gear with it in front of you. Sometimes pictures don't show everything. This gear isn't giving the clear pattern that the other one did.

skinny z

I'm no expert but it does unreasonably high on the tooth. I like the looks of the distinct margin in this pic.

vortec350s10

Well I played around with it for another couple hours last night and it seems no matter how deep I bring the pinion in, the contact never goes that low on the ring gear. I found out it definitely looks the best with the backlash set on the tighter side around .006 -.007" and I think I am going to settle on a .019" shim. Here's the pattern I'm going to run. Fingers crossed it's quiet like my other two setups. Wish me luck guys!

vortec350s10

I noticed my tapered roller bearings when I took them out had some slop - meaning my axle shafts had end play. I know when I installed them the backing plates pinched the bearings and held everything tight. They have like a lower race that is not attached to the inner race like most roller bearings. See the picture, does this seem normal?The loose race I'm pointing to with the punch. Both sides are the same way so I'm guessing it's normal.

vortec350s10

Well I've got it back together and drove it a little tonight. I haven't been over 55 but it's silent. I bought Valvoline 80-90 oil this time and it is way different smelling and it even feels different that the Master Pro cheap stuff. The Valvoline smells like gear oil normally does and is greasier feeling between your fingers. The Master Pro smells more like **** and is more yellow and not as slimy. We'll see it works out this time. I'm going to do the same break-in as last time but wait longer before I launch with slicks and when I do I'll give it more cool down time. I hope I won't have any more problems. Knock on wood!

skinny z

Keep it cool for the first little while. Don't let the lube get too hot.
Good luck.

vortec350s10

Update - I've slowly got about 250 miles on it and it's not perfectly quiet like the Motives were. So far I've been easy on it, and avoiding freeways and long trips. It is barely audible at 40-55 and then quiet and loudest right at 65mph. 5mph over or under 65 and its quiet. I might change the pinion depth a thousandth or two when I change the oil and see if I can quiet it down some. It's not bad but it's annoying enough to me where I would rather not have it howl for the next 10 years. We'll see.

vortec350s10

Well I changed the oil today for the first time on rebuild number 3. I've got about 700 miles in it, with the first couple hundred being limited to shorter trips and avoiding the freeways. It has been consistent so far in the noise department, just barely audible at certain speeds that I already mentioned above. I've started getting harder on it doing a few 2 or 3rd gear pulls here and there. I backed my boost down all the way on the MBC but it's still making about 8psi on the wastegate now that I switched back to my shorty exhaust. I added a magnet to my drain plug which is dead center on the bottom if the housing. There was a little bit of metal on it, the normal gray paste-like stuff you typically see in an automatic transmission pan. I would consider it a normal amount for 700 miles with all new bearings. I set the carrier bearing preload a little looser than before and it seems to run slightly cooler than build number 2. So far so good though.

lyrikz74

I have to hear how this ends. Goodluck. Subscribing

vortec350s10

I'm at about a thousand miles and have stopped holding back in the throttle department. I have noticed during several longer drives that the overall rear end temp is cooler than build 2, at least after it started to eat away the gears. Whether it's because of the different oil, the slightly looser carrier bearing preload, the cooler fall temps, or a combination, it can't be a bad thing. The highest I've seen is 150 on my gauge with build 3. The noise is still the same, it's tolerable. I decided not to mess with the pinion depth when I changed the oil, partially because I figured I would end up having to change it again since I probably wouldn't get lucky on my first try and who knows if it would even get any quieter. It could be worse and then I'd have to go the other direction and still may have settled back to where I started. I've accepted the fact that a little noise is the trade off for a bulletproof rear end. Which we have yet to see if it's true! Next season will be the real test. It'll be only my almost bald street tires for the rest of the fall to make sure she's as broken in as possible at least up to the street tires torque load.

If I could go back, I would have bought Motives again for build 3 but I wanted to change more than one variable. My advice at this point - run Motives, don't run cheapo oil especially for break in, and break it in slowly with street tires.

vortec350s10

Just a final update on the rear end. I've been thrashing on it as much as I can and it's holding up just fine. Plenty of times down the track with the drag radials and no ill effects have come from it. There's gotta be a couple thousand miles on it now so I think it's safe to say it should be good from now on, at least with my current setup.

skinny z

Happy to hear it all worked out.
It took four tries with my Dana to get it right. Two gear sets (went from a Richmond Sportman to a Yukon Gear) and two sets of carrier and pinion bearings (as the first set got eaten up). The first build lasted about 500 miles before a bearing went away completely. The second build was too loud and was getting worse. Those were by me. The third build went to a pro shop (that'swere the Yukon gear set went in) and it was loud too. I had it done a fourth time by the same shop (under warranty) and so far, after tens of thousands of miles and dozens of passes with slicks, it's holding up ok.
Good luck with yours.

badgta

iTrader: (4)

I would have went with a cast iron or steel pinion support instead of aluminum for rigidity and strength. Especially for a street oriented car that might see an occasional drag weekend.

antman89iroc

Vortec350, how's it holding up now? I am in the process of doing basically the same upgrade so I've been reading up on your thread.
Here's an interesting thought and something I have been considering. What do you think about the 3.50 ratio being possibly louder simply due to the tooth count? Since it is a semi-hunting ratio, that is it contacts the same teeth every two revolutions, it may be more prone to howling than a full hunting ratio would. I have been considering a 3.55 ratio for this reason. An old timer once told me that odd tooth number pinions are quieter than even numbered pinions. I wonder if this is due to odd tooth gears having a higher probability of being hunting ratios. One of the biggest desires I have is a noise free setup. I also notice that some 3.50 gears have 10 pinion teeth and some of the "higher performance" 3.50 sets have 8 tooth pinions. Fewer teeth mean larger teeth and presumably stronger. Do hunting ratios and higher tooth counts mean quieter running gears?