Ring and Pinion pattern (round two)

On my 8.25 pinion I went from a .031 shim pack to .028, both with .008 backlash. Am I going in the wrong direction?

Trying to get this buttoned up this weekend.

Thanks!

Had an hour to kill before heading to the post office this morning, tried a big move to a .020 shim to see what the pattern does.

Watching the pattern moving about and I wrong thinking around a .024 would be spot on?

Looking at the movement on both patterns between the 31-28 and then 20 I think I would try the 24...

Ended up with .026 tonight, had a hard time getting a good picture.

Looks good to me right in the sweet spot.

It's amazing how much more tooth contact you can get with a small move. Even though it is slightly deeper in the root I like it better.
Doug

Maybe just a little more backlash???

Already on the loose side at .008

Cleaned everything well and assembled with crush sleeve, again backlash at .008

Ran car on the lift for several minutes, no noise noted.

Went out on a road test, gear whine at very light throttle 50-65 mph and then seems to go away at that point. Silent below, silent above. Very slight whine on decel from highway speeds.

Youtube video of noise, had a camera on the back seat. Ignore the electric fuel pump buzz.

https://youtu.be/mvQuNokQ6L4

Anything I can adjust or am I screwed? Diff was a little warm after 15 minute road test, about 230-250F I'm guessing by feel. Pattern was approved by vendor. I'm ready to set car on fire.

Some gears do whine a little.

Can not tell much from your audio

I'll try and do a better one tonight, its loud though when its in "the zone" louder than it should be.

Vendor told me to drive it 500 miles and then change the break in oil.

Never heard of a gearset getting quite over time.

https://youtu.be/0SZzoAEZSb4

Camera in trunk, short clip

Put about 30 miles on car tonight, no notable change.

Pattern looked pretty good. With this gear set my bet is this is as good as it gets.
Doug

What brand gears? I installed blue box Motive, load as all get out, am going to get a set of OEM Spicer gears to hopefully make it better

I'd still try opening back lash a little

Motive Gear C8.25-373

Not acceptable.

I'll try moving the backlash out a touch and see if there is any improvement but if this is "as good as it gets" with this brand... I'll have future plans to replace them with a different brand and take the loss.

So what are my options?

I went with Motive Gears (even though a friend of mine advised against it, he just had a set go bad in 2000 miles in his big block Duster which had been setup by Strange Engineering as a complete assembly) but I wrote it off as a one off incident. Motive had them on the shelf and I was trying to make the Mopar event at the Valley October 8th.

There isn't a great selection of 3.73 for the 8.25" rear. I wanted just enough extra umph out of the hole to hit 12's but not impact the highway rpm's. That is why I stayed away from 3.90/4.10's. Might bump up to 3.90 just to get better selection.


US STANDARD GEAR has 3.90's, never heard of them.

https://www.summitracing.com/int/parts/spz-36010/overview/


Richmond has 3.90's, but not till November.

https://www.summitracing.com/int/parts/rmg-scr82503/overview/


G2 has 3.90's, don't know much about them either.

https://www.summitracing.com/int/parts/gta-2-2029-390/overview/


Yukon Gear 3.90's

https://www.summitracing.com/int/parts/yga-24002/overview/


Gary

If your pattern is spot on and the backlash is right in the middle of specs then sum it up to gearset quality.
I worked for DCA as technical training instructor and worked on enough DANA's and corporate axles to make me sick. That being said, there are a lot of factors, but at the end of the day if it's setup within specs and still noisy it'll be a gearset issue... Very hard to find stellar gearsets, we even used what they call matched gearsets when we had extreme situations.

I've been told, true or not flip or flop don't care, that ratio's above 3.55 can be on the noisy side as they are more a truck ratio, either way it's piss poor with today's manufacturing machinery that we are buying hit and miss sets, it's an install and prey situation today.
That blue box motive is exactly what I have only for a D60 in 3.73. I looked at your first few pictures you posted and straight away though, they will be noisy. The face of the tooth on drive and coast is not smooth they have marks across them from the machining. Mine are the same and I've gone out to 0.011" backlash which helped a little. I will be changing these out as they are loud and horrible, my pattern is spot on in the centre of the tooth.

A mate of mine has a set of red box motive 3.54 and they have been lapped btw, too the face is nice and smooth

I have run 4.11, 4.56, 4.88 on the street and all are silent compared to this hunk of junk living in my 8.25 rear. My GTX just ran 11.0 at 121 with a silent 4.11 gear set 3 weeks ago.

As a dealer tech I have driven many vehicles with ratios over 3.55 and they make no noise.

This gear set sounds like a dentist drill in the trunk and will be the last Motive set I ever purchase.

I actually liked the look of the .020 the most. I probably would have tried .022.
.026 or more loks like you're on the edge of the pinion's teeth. The less shim seems to have more the look of "flat on flat", if that makes sense.

I will only ad that I have run all of those ratios as well as a 5:13 and they were all quiet. The gears were made MANY YEARS ago but were quiet when set up properly. They were not "RACE ONLY" gears that can sometimes be known for making noise. bad gear set?? bad setup ?? don't know as I have never been trained in reading the patterns. I understand the basic principle but the pattern reading seems almost like black magic

Which is why I had the vendor who supplied the gear set approve the pattern before running the car.

"You didn't have it setup correct" excuse has just been eliminated.

Edit: I am considering dropping the shim from where it is currently at to .022-.024. Whats the worst that will happen?

Already junk as far as I'm concerned.

maybe your "trunk monkey" has a second job setup in there used for extra cash 'cause you don't pay him enough ? [i couldn't help myself. just funnin' ya !]

And to the OP, you could try it but I'm thinking it'll still be noisy,

Try a different dif oil? Synthetic?

Send the gears out to get REM finished. They will be smooth after that. Might work.

http://www.taylor-race.com/isotropic.cfm

Gears need to be set up before REM process and save all shims. You will not get a gear contact pattern afterwards.

They will go in the trash before I put any more money into them, thanks for the suggestion though.

Just having a run of bad luck this month.

Anyone have any feedback on these four companies? Yukon and Richmond I'm familiar with, the other two not so much.

back in 2003, i sent for info on o.d. systems like the gear vendor unit. one of those was a unit from U.S. Gear corp. at that time, that was who made strange parts. i don't know if U.S. Standard Gear is the same outfit or not. maybe a name change ? an economy version of the strange gear set ? i don't know, but that is the only thing that comes remotely close that i have dealt with. by the way, their o.d. unit looked like a quality part and was several hundred dollars cheaper, a couple inches shorter than the gear vendors unit, and the info came with an additional $200.00 off coupon to boot. i never acted on any o.d. unit at that time. for reference, the U.S. Gear Corp. had a chicago address.

Richmond I'm inclined to go with since they have been around forever but that doesn't seem to mean much these days.

US STANDARD GEAR - from what I have heard are over stock or non spec. Yukon GEAR

We have installed several Richmond sets and had pretty good experiences with them. Some have made a small amount of noise but very minimal and the customers have found it to be acceptable.

I installed a set of the G2 gears (3.54:1) in the Dana 60, and they are quiet. I never heard of G2 before, but the seem fine so far. Only have about 1500 miles on them.

Interesting.

Pulled everything apart again this morning after an hours run time and dropped the shim from .026 to .023 and set the backlash at .009

The noise moved up about 10 mph from where it was and seems to be in a more narrow window, it also sounds a touch more quiet.

Dare I move another .003 or just leave it the hell alone? I am getting tired of disassembling my 8.25" over and over. Good practice. I'll post the new pattern in a few hours.

The marks on the teeth look very, very coarse. I have my doubts about how well they were "lapped in" from the factory.

Gary

Without compound... .026 shim pack

.023 shim pack

thanks for the clarification.

.23 shim pack looks right on the money. What if you take out some of the .008-.009?

Might try this stuff too: Red Line 58204 Heavy ShockProof Gear Oil

You mean reduce the backlash from .009?

Thinking of taking the car to The Valley this weekend to see if it breaks into the 12's. Sunday is looking to be 53F and its one of the last days the track is open. Not the best conditions but running out of options this late in the year.

Put some miles on it this weekend, noise no better, no worse. Fixed an oil and power steering leak. Have some AFB tuning to do, slight off idle stumble when light on the pedal. Emulsion tube needs to be drilled out a touch more. Cruise is perfect, WOT needs a little taken out of it. Nice driving around with the wide-band.

At the moment I'm considering Richmond 3.90's but that will have to wait till sometime this winter.

Gary

I installed a motive set in my brothers 9" ford a while back. I remember the sheet of paper that came with them called for more backlash than the original factory service manual did. I was sort of reluctant to do that , but did. So far so good with it. Might be worth looking into, wish you the best. Every set up I have ever done I have only take apart 20-30 times to try to get it the best I can. Way to much OCD for me to do that for a living! LOL
Matt

Backlash set to loose side of Motive sheet. Factory is 005-008