New gears and alot of noise

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mean318

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I have just recently put together a 742 case with strange 4.11's and sure grip and it says the gears have to broken in, first with the rear in the air and then drive for 10 miles but as I had the rear in the air there seems to be alot of noise. Could it be that the diff was dry for so long? I put royal purple 75W 140 gear oil in it. could that be my problem? I know the backlash and pinion depth are right. The instructions from strange say there is some noise to be expected, but I am wondering how much is acceptable?
 
mean318 said:
I have just recently put together a 742 case with strange 4.11's and sure grip and it says the gears have to broken in, first with the rear in the air and then drive for 10 miles but as I had the rear in the air there seems to be alot of noise. Could it be that the diff was dry for so long? I put royal purple 75W 140 gear oil in it. could that be my problem? I know the backlash and pinion depth are right. The instructions from strange say there is some noise to be expected, but I am wondering how much is acceptable?
Click to expand...


Yep how much is too much hard to say? Is the noise worse on acceleration or coast? Gear pattern may be to high or low? But I have a lot of experiance over the years and some gear sets are just noisy. That being said the higher ratios like 4.10, 4.56 etc are a little more noisy because the pinion has less teeth, spins faster etc, but can still be setup pretty quite. I kinda do not but the break theory. If it is noisy I dought it will get much better.

And what do you mean by the diff was dry so long? Do you mean while the gears were out? This would not matter, it only matters that it is full after the gears are back in..

good luck maybe someone else has more input, but need to know when the noise happens worse, accel or coast?
 
WOW that was quick! Well it is noisier during accel and and higher speed such as 3rd gear is louder than 1st. Almost no noise during decel, reverse about the same noise as first naturally.
 
Sounds like it is a little to tight pinion depth is too deep. Trick is to have the depth and a decent pattern. Sometimes you shim the pinion to get less depth then you need to shim the carrier to get the ring back into the pinion to get a good pattern back
 
What kind of noise are we talking about? I have Richmond 4.10s in my 8 3/4, and they whine a little, especially on deceleration.
 
how do you know the pinion depth is correct?
just wondering how you detrmined this?
if you used a measuring tool, or equivalent that is only a place to start from...you need to take a pattern and adjust from there sometimes
 
Sanguine said:
how do you know the pinion depth is correct?
just wondering how you detrmined this?
if you used a measuring tool, or equivalent that is only a place to start from...you need to take a pattern and adjust from there sometimes
Click to expand...

The pinion gear will be engraved with a number. This is the depth of the pinion gear from the centerline of the carrier. This measurement must be right. Pinion depth is not to be changed to change the pattern on the gear. When the gears were made this was the depth of the pinion to match the ring to have the gears mesh correctly. If a gear set whines and the depth is right it is pretty much the way it is going to be (as long as it is not bearing whine). I have had some gear sets very quiet and some whine. It is just how the gears were ground. Like mentioned the lower gear sets do/can make more noise than higher gear sets.


Chuck
 
I got to disagree with that to a point...
in a perfect world, yes, you use your tool, +/- whats marked on the pinion and theoretically it where is supposed to be...
suppose the pattern doesnt come right and is noisy..it does happen..ive seen it...and corrected it by +/- shims on the pinion
different ways to get things done i guess
 
If the pinion depth is correct as stated on the pinion then the pattern will be correct. The manufacturer of the gears has set the gears to run at that pinion depth, period. If the pattern is wrong then the pinion depth is wrong and not what is specified on the pinion.

If the pinion depth is correct and the backlash is correct and the gear set makes noise it will have to be or purchase another set which could be quieter than the original set.

Chuck
 
all im saying is if everything is correct and it still makes noise,like you said, sometimes you can deviate from what the manufacture had intended to correct it rather than buying another gear set or living with it
If you want to live with a whiny gear set or change em until you find one that you're happy with, be my guest...

id change a shim and correct it myself if possible...
 
Well I guess I misled you all a little, at time of first post I had only had it in the air and it made noise. After I took it out for a drive I had realized it was making too much noise especially on decel around 2300-2800 it was really loud and on accel it was still makin too much noise. I guess I didn't get the depth right (it looked good when I set it up!). I was also told I should check the backlash in more than one place. I will be taking it out again sometime in the next week. I would like to thank you all for your input it was very helpfull!! On another note though my baby sure gets up and goes with those gears!!!
 
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