You should try posting pictures of the teeth contact pattern if you can. Are you doing your own labor?

 

Unfortantly don't have pics of the contact pattern, even though I asked for some pictures to be taken this time round. I'm probably a decimal point out on my backlash, it's 0.07 I imagine, but I'll be emailing the garage on monday about the current noise and to confirm settings.

Since the latest time it's been back to the garage, I've noticed a new noise at very low speed (and noticed this noise kind of pulse if I pull up gently in neutral):
[media]http://www.youtube.com/watch?v=tp70t1N7Vdw [/media]


Here's a vid of normal driving (I keep pulsing on/off very gentle light throttle, so you can hear how it triggers the sound, no sound on coasting):
[media]http://www.youtube.com/watch?v=zaVmOAzKINA [/media]


Even if this diff kit does make some noise, this seems out of the ordinary I think? Oppinions on the cause of the noise welcome!

On Monday, I'm gonna speak to the garage about the noise now, try and get a better understanding from here as to what might be the cause. I don't have access to tools for measuring backlash and seperating bearings, otherwise I'd love to have a crack at it myself now. I think what I might do is source another diff from a breakers, so I've got somthing to swap on whilst I'm trying to get this one as quiet as possible.

 

My 4.44 whined before my diff blew up.

 

It's hard to tell,from the Video,but some whining is normal,with aftermarket gears.

I have 4.57 gears from Richmond gears,bought from "Rick's",and installed properly,and they whine a little,around 90 kms, (55 mph.)in 6th gear.
Those gears were supposed to be more quiet than the 4.56,

At the Lake George meet,two years ago,I had "XViper"take a ride in my car,and he confirmed,that the noise was normal.

In order to reduce the noise,he advised me to use,Amsoil 75W140 gear oil,and it helped a little.
Had the gears installed for 4-5 years,and other than the noise,never had a problem,running strong...

 

Well, I have the exact same 4.44 from Motorklasse and it's absolutely quiet. I put it together myself and been beating the piss out of it for 4000 miles trouble free.

My backlash is set to 0.0035 inches (0.0889 mm).

You might want to check the backlash on every tooth, as some of their gears are known to be defective. For example, the backlash may be correct on one side of the gear, and 180 degrees apart, it falls below 0.002.

 

I know this is a super old thread but i'm wondering if you were able to resolve the problem and how?

Cheers

 

I have that same motorklase kit. So far 20 k and some miles and still intact. This is what I did....

- i did what billman suggested and had the old bearings ground open from the inside.
- my stock shim ( pinion shim on my stock pinion gear) seemed to be the best fitting shim.
- i used the j's solid collar sleeve and custom made the shim for that kit instead of buying the j's shim kit.
- i set my back lash to .002 to .004. Inches. (.05 to .08 mm) .These gears are not the best quality. They are kinda oval but still will be in spec. Youll notice it when you are setting the backlash.
- pinion load i set to 12 in lbs .
- i torqued the pinion nut to 125 ft lbs. this can be done only with a solid collar sleeve.
- setting the backlash is tricky. The manual shows a way of using a pull gage for setting the preload on the carrier bearings. i used my readings from the pinion nut and calculated.
- since i knew i had 12 inch pounds. With the backlash set , i got a reading with the ring gear assembled and
got about another inch pound or less, hardly noticable.
- my goal was to set the carrier bearings preload to 20 in pounds. This number was recommended to me by another differential builder.
- so that would be 20/ 4.44= 4.5 in lbs. i was looking for a total of 17 inch pounds at the pinion nut. I realy got 18 in pounds. That was close enough for me.
I did the break in s2kpupdaddy recommends.
As far as whine, barely noticable. Sounds almost as loud as my stock one. I think my tranny is much louder.
Hope this helps.

I skipped over most details on assembly, im just letting you know the specs i used to assemble mine.

 

Didn't notice at first, but dam this is an old thread.Nevermind then!

 

nah mate, your post has helped me significantly. Would you say buying a solid collar is much better than the oem one?

 

I am trying to minimize the chance of my differential failing by using a solid sleeve. I have heard of the pinion nut having the possibility of backing out on a standard crush sleeve.