wingit

Hi Guys
I had a small rear noise, not a howl for 2k miles. diesel gen3 2500.
Mechanic did 2 carrier brgs and cleaned inspected the rest and whl brgs.
New carrier brgs=B-lash was .0075 dry, then reset to .005 dry
for more ideal gear pattern but noise is the same on decel from 45 to 25 mph.
The noise was different when we heard bad carrier bearing non pres side but not this whine.
This shop uses only mineral 80/90, never synthetic.
Its very quiet on jack stands up to 60+ mph. for and reverse if it matters.
Now What should we do ? look at the Pinion brg again ?
I'm questioning the guy who said that looked OK. I will indicate that shaft.
Frustrated in Mn. we'd like to see friends in Utah.
thanks, lew

C Schomer

I'm not the greatest on rear ends but I've done OK. Did he check the pinion preload/rolling tq when he had the carrier out? IMO, he should have replaced those brgs too or at least replaced the rear pinion brg but that gets into depth setup and maybe he was afraid to get into that. That b-lash is fine but the pinion depth is probably off cuz of the old brgs. FWIW, I bought my 03 when it had 25k miles and I'm so fussy, I checked the total rolling tq when I got it home and it was down to 10 in/lbs and I was quite disturbed. RP 85w140 did a great job when I had a problem D80 so I've run the same in my 03 and it's doing just as well as far as minimizing wear particles on the magnet and I haven't had to touch any brgs yet. I ran 85/140 in Co and there was NO downside. For Mn, I'd run 75w140 syn. Craig

BigIron70

You need to use synthetic in these diffs, they do run very hot and synthetic will not break down like 80/90 will at high temps. Replace the pinion bearings and use new crush sleeve and nut. Set pinion turning torque to 25 inch lbs. and then set total turning torque once carrier is in and backlash is set to 50 in lbs. turning each adjuster equal until total turning torque is reached.

wingit

Thank you, this is what a guy needs.
I went 25 mi. to work, got an indicator clamped to the housing and at the pinion shaft
I can easily move it up/down .001..I guess any move means no pre load.
Maybe its the yoke plate moving on the spline shaft .001, but it whines.
My 3rd time back Mon. and i'm not happy. It happens to us all,
Stress when Its not a good week for this.
They are friends and the only shop around doing all this.
Happy Mothers Day to your Mom, for having Son's that help others.
and thanks again, lew

He died laughing or crying, can't tell

wingit

Took it apart today
It looks like there was no pre load on the pinion brgs.
Both carrier brgs show one sided 60% contact shading
with 300 miles since the new carrier brgs. That concerns me.
I'm curious what it sounds like tomorrow.
We'll do new pinion bgrs and try for no noise again.
happy day

C Schomer

Even tho brgs are made to very close tolerances, it still took me 3 tries with the shims to get the preload right on my D80. Putting all the oem shims back in on the first try didn't even come out close. And yes, if you had .001 on the dial, there was no preload left. You also have to get the tooth contact pattern right. Craig

wingit

Very scary, I worked on ring/pinion problems in boat stearn drives to trucks before, and they are trouble. I made racing props for boats and molds to make Alum impellers with airfoil shapes to improve flow paterns like wind tunnel proof of theory problems. My head still hurts dealing with some people when they say "I did hundreds of rears", and there is nothing else I can do. The shaft moved up & down.001 easily, =No pre load.
I need free universal OBO ins for my truck to take all the worries away.
Your link to specs help back me. Thanks guys.

wingit

3rd time's a charm..now I have all new brgs. First time He said pinion's were OK.
I feel better with 4 new . The Pinion brgs pre-load is now set at 20/25 in lbs.
Would 15 be more ideal for a part time tower ? I run 80 mph empty to Fla.
Does this loosen up temporary with heat and some miles ?
I imagine the whole rear and shafts heat and expand so the pre load can vary.
I guess the Pinion shaft is hotter than the housing=less pre load ?
And even more towing in mountains. A curious mind never rests.
The whine is almost gone. Now I'm using 75/140 Valvo synthetic.
thanks again, Happy day

wingit

One thing I didnt check before writing this is the temp.
Now it runs 160degrees at 55 on flat road empty.
Ohoh brgs are too tight, and they wont work on it anymore.
they said they have bent over backwords,
but there was a reason every time I went back,
from no pinion pre load and whining to this.
Now short of taking it apart, I am trying to determin threads per inch
to see what 1/16 to 1/8 turn back will take off the pinion pre load.
1/16 the first time to check temp at 55 again. Why should I have to be the test pilot ?
TTR=pinion and ring gear=new brg=30/50 inch lbs
TTR=pinion only new brg=15/25 inch lbs
Mine set at 25 in lbs, I question the old torq wrench. Now running too hot empty
based on my truck history and posts hauling 8k trailer at same 160 degrees.
I think the spacer can spring back some. That material shouldn't take a set
and it has a bow in the center designed for spring loading for wear.
Started this 5/2/15, and I won't run my truck untill its something better.
Now it might never be varified in the range it should be.
I hated annual inspections on my plane, as it wears things out taking it apart so much.
Both planes needed work. sold with digital system monitors and my custom paint.
Some of us just like things to run right, Planes Boats Beemer bikes Trucks and Tractors.
I operate a Tool & Die shop for 36 years with my son doing the work ourselves

patdaly

I wouldn't screw with it, from BI70's file it says 30-50 Lb/In with new brgs, and you say it was set to 20-25.

Couple that with the AAM having a crush sleeve, if you back the nut off, the crush sleeve won't expand, so you will lose your pre-load right away.

I know they run hot from the factory, perhaps someone can chime in if 160 is excessive, to me it doe not seem so.

wingit

Hi Guys
Update, I found the rear was filled 1.3 quarts low.
Adding that amount lowered the rear temp 15 degrees.
It runs 100 degrees over outside temp pulling a trailer about 3k lbs. @60mph. flat road for 15 miles. same temp as empty before adding 1.3 qts.
Other posts pulling 7k to14k trailers are claiming 100 deg over OAT in 90 deg temps and or hills. Mine still seems too hot compared to the posts.
They are back pedalling and saying I was too fussy. I think the pre-load is near the high limit, so I'll leave it.
Thanks allot for the help, Have a nice memorial weekend. lew

wingit

What would a vote be.
Now it's persoanl, I'm being attacked claiming I'm too picky.
I had to be there for hours each time. They sent me out low on oil each time.
400+ miles later there was metal on the magnet adding 1.3 quarts of oil to the right level.
I have less confidence in the rear. I'm sure there is no warranty plus the stress for 4 weeks.
Paying once is one thing,buttttt I had to work and fight to save the rear from ruin.

wingit

6-15-15
Now about 600 miles later I'm wondering what to do next.
about 200 miles 3 times since the 3rd service, Brg metal on magnet.
Maybe check combined TTR without talking it apart ?
I should have watched both Pinion alone and Carrier combined TTR and writen down the numbers.
I didn't see the combined checked.
Flat road 70 OAT
65MPH 3k trailer 182 degree rear.
70 MPH 3k trailer 195 degree rear.

wingit

4th Time
Checked TTR Pinion and carrier, now its 17. full of syn oil.
I saw the Pinion at 25" lbs the last service.
What is correct total TTR guess full of oil ?
I didn't see the Carrier pre load set. It looks like there is none.
We hear a rear howl when temps get high= 195 degrees.
Then it goes away the next day , cooler and driving 55
I'll run it and watch the magnet maybe. We all need clarification
and closure from this unfortunate hardship.
I'm waiting for AAM response.
loosing sleep in paradise

wingit

5th service.. Since they are buzy and short handed,
I suggested this easy change. Seeing 17" lbs TTR total on visit 4
I assume carrier is low TTR, So we checked backlash = .005
and moved adjust ring over one hole to get some carrier pre load
and b- lash to .007..2 birds with one stone. left D-shaft and axles on.
I know they have time and money in this too and they said I can walk
or re do it with new brgs, That's big of the owner.
My guess B-lash is too close with low carrier preload makes a vibe howl.
It took only an hour and it might be OK except AAM said watch
the magnet for brg metal + wheel brgs and seals as it was run low on oil.
Some shops run in changes, so I did Jack stand run 20 MPH for 1 hour.
Also I don't drive enough in 2 years to show a shorter rear life.
Thats life, they aren't trying to cheat me.
happy day