HELP advice on gear pattern

uncleg
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HELP advice on gear pattern

Postby uncleg » Thu Dec 29, 2011 8:43 am

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I need some advice. I've been playing with this for a while now, different sites seem to give conflicting ideas about what the gear pattern should look like.
I have a 8.5 GM with a new set of richmond gears 373.
I used the ratech pinion depth checker and set the depth how they recommend. I'm within .001 of the stamp on the pinion. The ring gear is stamped .010 backlash but it looks better at .013 (see pics).
I have looked at this thing for so long I need an objective opinion before I do something drastic any help would be greatly appreciated.

Thanks
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101_9504.jpg

67drake
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Re: HELP advice on gear pattern

Postby 67drake » Thu Dec 29, 2011 9:21 pm

I'll throw my opinion in. To me it looks like the pinion is a hair too close to the ring gear. I'd say pull another .001-.002" out from under the pinion.
I'm still a rookie though,I would of coarse wait for Jim's blessing! It just helps me learn to look at patterns too. 8)
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67drake
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Re: HELP advice on gear pattern

Postby 67drake » Thu Dec 29, 2011 9:23 pm

I'll throw my opinion in. To me it looks like the pinion is a hair too close to the ring gear. I'd say pull another .001-.002" out from under the pinion.
I'm still a rookie though,I would of coarse wait for Jim's blessing! It just helps me learn to look at patterns too. 8)
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monzaz
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Re: HELP advice on gear pattern

Postby monzaz » Fri Dec 30, 2011 12:09 am

Ok well you are definetely TOO...DEEP. The pattern is too deep on the coast and the driveside telling us that you need to remove pinion shim from the pack. What shim thickness are you using?

Usually around .038 for stock GM gears. Richmond and most aftermarkets will be kind of all over .

Pinion depth tools are great for getting you in the ball park WHICH the pattern is... But this WILL MAKE NOISE if you leave it alone.

I would say take at least .004 to .004 out.

IE - if your shim is .040 go to .036 area. DO check the backlash at .010 that is a good swipe so what ever you are doing to get the pattern as visible as you do KEEP ONE DOING THAT. :)

So keep at it your close but we need to fine tune this set yet.

Send more pictures and please give the pinion shim thickness for the set-ups you send along with the backlash. MAKE sure the carrier shim pack is good and snug also you have to tap them in and the posi carrier set-up should NEVER be as easy to remove by hand it should always need to be pried out of the case with a j bar . IF you can pull the carrier in and out by hand it is NOT ENOUGH carrier bearing pre-load. add a few thousands to each side or the side that needs more or less backlash.

Jim
J D Race

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monzaz
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Re: HELP advice on gear pattern

Postby monzaz » Fri Dec 30, 2011 12:18 am

Here is where the problem is-
The red arrow - shows too much in the root / valley it is too sharp of a line compared to the peak of the gear which is at a ark showing not enough contact in the mid to upper part of the gear.

Same goes for the coast side which is even worse.

now when you move the pinion out away from the ring it will contact in the middle of the gear.

So take out about .003-.004 and see where it goes. :)
Attachments
DRIVE SIDE problem with this setup 2.jpg
DRIVE SIDE problem with this setup 2.jpg (22 KiB) Viewed 7482 times
COAST SIDE problem with this setup 1.jpg
COAST SIDE problem with this setup 1.jpg (23.19 KiB) Viewed 7482 times
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uncleg
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Re: HELP advice on gear pattern

Postby uncleg » Fri Dec 30, 2011 10:27 am

Thanks for the help.
I think I have 40 under the pinion, I'll check and remove .004.
The carrier is tight getting in and out, I use a pry bar and turn the pinion to get it to pop out.
As far as the pattern, I put 1 axle in put the drum on and adjust the brakes shoes out until I get alot of drag, it takes a few minutes but it definitely gives me a good pattern.
I'll do it this weekend and send more pics.
Thanks again everybody.

uncleG

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monzaz
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Re: HELP advice on gear pattern

Postby monzaz » Sun Jan 01, 2012 6:49 pm

Yes good work with the drag. We just usually jam a rag in between the housing and the run in the direction we are turn and it produces nice drag too. Try it and see if you like.

Yes .040 is much. please list the backlash your using too. keep it at .008-.010 do not go over that wider. .036 sounds like it might work good. Watch out for the shims they sometimes have flashing from being stamped which will give you a false measurement.

Jim
J D Race

uncleg
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Re: HELP advice on gear pattern

Postby uncleg » Mon Jan 02, 2012 12:45 pm

101_9507.jpg
Ok.
Here are some new pics with .036 under the pinion and .011 on the back lash.

Let me know what you think.
uncleG
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101_9510.jpg
101_9509.jpg

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monzaz
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Re: HELP advice on gear pattern

Postby monzaz » Mon Jan 02, 2012 3:21 pm

Better- try free spinning it with out any drag and more oil and shoot a couple more shots. Also go all the way around and look at all the teeth. this way you know there is no issue with the run out on the gear...the paint is come off the painted teeth and onto the none painted teeth leaving a photo negative affect. :) Jim

Are you using a NEW bearing or a honed out used bearing?

put the back lash at .009 or .008 if you can

Also how does it feel when free spinning the ring around pulling and pushing forward and reverse? Does it feel about the same forward and it does in reverse? IF so then That is a GOOD thing. Is it noce and smooth both ways?
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uncleg
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Re: HELP advice on gear pattern

Postby uncleg » Tue Jan 03, 2012 11:41 am

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new pics using honed out bearing, first pics pressed bearing.
When spinning pinion feels the same both directions.
I got the backlash down to .009 all the way around, with about a 1/2 thousandths variation.

3 pics no load

next post loaded carrier

uncleg
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Re: HELP advice on gear pattern

Postby uncleg » Tue Jan 03, 2012 11:44 am

101_9526.jpg
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loaded carrier

Thanks uncleG

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monzaz
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Re: HELP advice on gear pattern

Postby monzaz » Tue Jan 03, 2012 8:18 pm

Humm- Still looking for a better pattern...??? Just seems to be some inconsistency It should not have changed so much now there is LESS swipe. Sure you have the pinion shim measured correct and have the same pre load on the pinion bearings. MAybe try to spit the difference at .038 where I would have started to begin with. Make certain your carrier is seated in the saddles and the caps on good too. NO dirt in the saddles etc. ??? Just a bit thrown as to why your pattern got so changed so much...???

SOME times this does happen but usually because of the reasons I stated - Make certain you have it all double checked and move the pinion to .038 since you have to pull it all to clean and check anyway. I am sorry I just do not want you to set-up the rear unless we agree it is correct.

Also do not be afraid to spin that ring gear around many many times 5-6-7 if it takes to get a real good idea where this thing is running. Jim
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uncleg
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Re: HELP advice on gear pattern

Postby uncleg » Wed Jan 04, 2012 7:13 am

Thanks Jim
I'll pull it all apart clean it again put in .038 under the pinion, and see what I get.

Where can I purchase just pinion shims assorted sizes without buying a whole kit.

uncleG

uncleg
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Re: HELP advice on gear pattern

Postby uncleg » Wed Jan 04, 2012 10:46 am

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Jim

Cleaned everything backlash at .010 in 3 spots around gear.
I left .036 under pinion.
looks better, more consistent.
no load.

uncleg
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Re: HELP advice on gear pattern

Postby uncleg » Wed Jan 04, 2012 10:50 am

101_9544.jpg
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loaded pics same setup.


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