need4fun2469

I have a set of Yukon 3:89's in my 9" and they are really quite. I did the 500 mile break in and didn't run over 70 mph as directed.

The guy who set them up had them dialed in also. This is one of the most important things for quite gears.

Heyfred

iTrader: (10)

Had a bad noise, vibration starting at 60mph after installing new set of 3.70 Yukon gears up. Everything new in the rear except for the case. (Ford N case) After removing, made the decision to change the new pinion support bearing with another new one, noticed a hairline crack in the support boss. Replaced the case.

Finished the set up on the 9" new center case. Pattern looks like the above. Slight noise starts at 60, I think it may be caused by the rod ends on the suspension components.

You can still hold a conversation without raising your voice and when you turn the radio on you don't notice the noise.

1ta2nv2000

iTrader: (5)

Yukon 3.89 gears in my MWC. Im at 150 miles on break in and they sound like my stock rear. Except when I let off they are very loud. They are getting better during break though.

redtail2426

iTrader: (10)

good to hear,yeah my richmonds i have now are so loud that when my brother was driving next to me on the expressway he said it was sounding like a frieght train was coming.Mine are so loud anything is an improvement.Mine start howling at 10,and start screaming by 40 ,at 60 the radio cant be heard

96lt4c4

iTrader: (5)

I was told the off or odd ratios make noise. 3.75, 3.89.

redtail2426

iTrader: (10)

i ordered the yukons,but was called the next day from randys ring and pinion,they told me they just ran out of sets.So i just brought the center section to a local fab shop,and they ordered a set of motives to put in.And i also found out my midwest gears were not setup correctly,and thats why they screamed.The pattern was to close to the face on the drive side,and you could see it was taking the edge off the face,but was perfect on the coast side,which explained why it was dead quite when i let off the gas.Now what i dont understand,is when midwest sent me the rear,they left marking compound on the teeth,and it looked great.I think if they had it set just a hair closer to the flank,then it would have been okay.Owell im not gonna bitch about it,the guys at midwest did all they could to help me with it,but i didnt want to mess with making the adjustments,so i just took it to the local fab shop and let them change the gears right out for new ones.The last thing i wanted was to keep pulling it apart and trying to get them quite

96lt4c4

iTrader: (5)

So was the pattern running off the face of the tooth? Or was there some clearance or paint over the pattern? How did it compare to this picture? These are my Motives right ow as they sit on my bench. I havent had a chance to put the center section back in the car.

redtail2426

iTrader: (10)

here are a couple pics of the drive side pattern.You can see where the teeth were making the main contact,but you can also see they were still in contact off the face and heel of the tooth.With marking compound it would just show contact in the middle of the tooth,but under any load its touching a much bigger area.I dont know thats just my guess

redtail2426

iTrader: (10)

here is the coast side,which shows it was not running off the edge of the tooth,which was also dead silent on the coast side,and sounded like a tornado siren on the drive side

CamaroZ28_LS1

iTrader: (5)

my 3.75's are a bit noisy but only at low speeds and corners

96lt4c4

iTrader: (5)

Its hard to tell by your pictures but it almost looks to me like the pinion is too close. The patern is to far down in the tooth. If you look at my coast pattern there is no straight line at the bottom. Yours has a straight line and a domed look to it. That gear is not even close to being right.

96lt4c4

iTrader: (5)

I have finally found the source of my noise and it was caused by my pinion support moving. So, I should not have bashed the Yukon gear. I am sure the Yukon would be quiet.

https://ls1tech.com/forums/gears-axl...bolt-case.html