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-   -   Contact pattern (https://67-72chevytrucks.com/vboard/showthread.php?t=810905)

Dleslie212 08-22-2020 03:21 PM

Contact pattern
 
Was hoping somebody could take a look at my ring and pinion contact patter and telle what they think. First time doing this. I'm sitting about 5 thousandths backlash on the ring gear, and pinion is with 2 thousandths depth of what it calls for

https://imgur.com/gallery/PhIECi0

mongocanfly 08-22-2020 04:05 PM

Re: Contact pattern
 
Pinion to shallow..

AussieinNC 08-22-2020 04:13 PM

Re: Contact pattern
 
Yep, pinion too shallow...add a 20 thou shim and retest...you want pattern in center of ring gear tooth...

Once you get pattern correct, then set backlash...

Dleslie212 08-22-2020 04:34 PM

Re: Contact pattern
 
Quote:

Originally Posted by AussieinNC (Post 8796345)
Yep, pinion too shallow...add a 20 thou shim and retest...you want pattern in center of ring gear tooth...

Once you get pattern correct, then set backlash...

So get pinion depth done first and then backlash. Gotcha. So I'm already pretty close to the depth marked on the pinion face. I'm using a level across the face where the diff cover sits, then using depth gauge of of my caliper, zeroing it, and then checking difference down from the same level to face of where the carrier brackets bolt down

Also, when checking rotational force of the pinion after putting in the new bearings and what not, is that checked while the carrier is in place? Or only while the pinion is in?

mongocanfly 08-22-2020 05:00 PM

Re: Contact pattern
 
Dont worry to much about the pinion markings..you need to get the depth set...I set the rotation torque with the carrier out..
You've got to have it all set together ..depth, backlash, rotation...
As you move the pinion deeper, you'll have to adj carrier shims as well...no way to tell what you have till it's all assembled

Dleslie212 08-22-2020 05:08 PM

Re: Contact pattern
 
Quote:

Originally Posted by mongocanfly (Post 8796357)
Dont worry to much about the pinion markings..you need to get the depth set...I set the rotation torque with the carrier out..
You've got to have it all set together ..depth, backlash, rotation...
As you move the pinion deeper, you'll have to adj carrier shims as well...no way to tell what you have till it's all assembled

I'm going to go ahead and add 20 to the pinion tonight when it cools down a bit and then post a few more pics. Thanks for the info

kwmech 08-23-2020 06:44 PM

Re: Contact pattern
 
Looks too deep to me. Pinion has to come out to center the pattern. First pic is the coast side. I'd take out 10 then check it. May end up taking out more

Dleslie212 08-23-2020 06:53 PM

Re: Contact pattern
 
Quote:

Originally Posted by kwmech (Post 8796834)
Looks too deep to me. Pinion has to come out to center the pattern. First pic is the coast side. I'd take out 10 then check it. May end up taking out more


Early this morning I ended up adding all my shims and all it kept doing was making the pattern worse. I finally took everything out except a single 20 thou shim and it's almost perfect now.

kwmech 08-23-2020 10:57 PM

Re: Contact pattern
 
Give us a pic

Dleslie212 08-24-2020 09:21 AM

Re: Contact pattern
 
Quote:

Originally Posted by kwmech (Post 8796979)
Give us a pic

I’ll snap and post a few tonight after work. Hopefully it’s good. I tried heating up my pinion bearing in the oven and dropping it onto the pinion. I must have not had it hot enough, because it barely slid on and then instantly got stuck, so now I can’t slide the pinion back into place to get pics of the pattern. I have it sitting next to me in my work truck so I can drop it at a machine shop this morning to have it pressed the rest of the way on.

Whie I’m here - I bought a crush sleeve eliminator kit, and my install kit came with a standard crush sleeve as well. I’m leaning towards using the eliminator kit, but can’t really find any decent instructions on how to install it. Do I just torque the pinion nut to a certain setting with a certain shim, check bearing preload, and rinse and repeat till I have about 20 inch pounds? What torque should the pinion nut be set to?

Edit - after a little reading, I think I may have screwed up. I did all my shimming and checking contact patterns with my old crush sleeve in place. Is that a mistake? I’m thinking it doesn’t change the pinion depth, so it should be fine?

mongocanfly 08-24-2020 09:31 AM

Re: Contact pattern
 
I'd highly recommend the crush sleeve eliminator ...itll need shimmed to get the proper rotational torque..
Your Instructions should have your pinion nut torque...what axle do you have?

Dleslie212 08-24-2020 09:33 AM

Re: Contact pattern
 
Quote:

Originally Posted by mongocanfly (Post 8797095)
I'd highly recommend the crush sleeve eliminator ...itll need shimmed to get the proper rotational torque..
Your Instructions should have your pinion nut torque...what axle do you have?

There were no instructions at all with the eliminator kit.
Rear end is a 12 bolt Chevy truck rear end

mongocanfly 08-24-2020 09:51 AM

Re: Contact pattern
 
https://m.youtube.com/watch?v=iZInF95qHX8

I think this explains it..having internet issues today..
Measure your old crush sleeve and start there with the eliminator and shims
With the eliminator I think about 125ftlbs on the pinion nut

Dleslie212 08-24-2020 09:57 AM

Re: Contact pattern
 
Quote:

Originally Posted by mongocanfly (Post 8797105)
https://m.youtube.com/watch?v=iZInF95qHX8

I think this explains it..having internet issues today..
Measure your old crush sleeve and start there with the eliminator and shims
With the eliminator I think about 125ftlbs on the pinion nut

That video mostly just talks about the differences between the crush sleeve and eliminator, not really installation. Thanks though

mongocanfly 08-24-2020 09:59 AM

Re: Contact pattern
 
Ok ..I couldnt get it to play past the 1st 20 secs..

mongocanfly 08-24-2020 10:06 AM

Re: Contact pattern
 
I know there's some YouTube on it...but I cant get em to play..

kwmech 08-24-2020 01:46 PM

Re: Contact pattern
 
Quote:

Originally Posted by Dleslie212 (Post 8797092)

Edit - after a little reading, I think I may have screwed up. I did all my shimming and checking contact patterns with my old crush sleeve in place. Is that a mistake? I’m thinking it doesn’t change the pinion depth, so it should be fine?

Crush sleeve not needed at all to check set-up. Bearings need to be seated and a light drag on the pre-load to get gear contact pattern. That's all.

Dleslie212 08-24-2020 01:47 PM

Re: Contact pattern
 
Quote:

Originally Posted by kwmech (Post 8797202)
Crush sleeve not needed at all to check set-up. Bearings need to be seated and a light drag on the pre-load to get gear contact pattern. That's all.

Not needed, it will it mess up my pattern and backlash if I happen to have put the old one back in during mock-up? I’m assuming no

mongocanfly 08-24-2020 02:54 PM

Re: Contact pattern
 
I missed the edit...but like kw said...leave the crush sleeve out during setup..

Dleslie212 08-24-2020 09:20 PM

Re: Contact pattern
 
Here is the latest pattern. Hoping it's good as I had the bearing pressed on this morning. Thoughts?

https://imgur.com/gallery/PGOsvjm

kwmech 08-25-2020 11:13 AM

Re: Contact pattern
 
I would have tried to go just a tad deeper-- maybe .003. Centered contact seems to be a bit off center to the outside. But that is way better than the previous pic. Coast looks good. Where did the backlash come out?

Dleslie212 08-25-2020 11:42 AM

Re: Contact pattern
 
Quote:

Originally Posted by kwmech (Post 8797718)
I would have tried to go just a tad deeper-- maybe .003. Centered contact seems to be a bit off center to the outside. But that is way better than the previous pic. Coast looks good. Where did the backlash come out?

Backlash is pretty tight around 005. The manufacturer recommends 7-9. I didn't bother messing with that last night because I really really expected to hear that the pinion depth was wrong, but I can mess with that tonight and post more pics.

It's just weird that the pinion depth would be so far off what spec says. Spec calls for 2.751 and I currently have it sitting around 2.880 I think

kwmech 08-25-2020 09:00 PM

Re: Contact pattern
 
Quote:

Originally Posted by Dleslie212 (Post 8797740)
Backlash is pretty tight around 005. The manufacturer recommends 7-9. I didn't bother messing with that last night because I really really expected to hear that the pinion depth was wrong, but I can mess with that tonight and post more pics.

It's just weird that the pinion depth would be so far off what spec says. Spec calls for 2.751 and I currently have it sitting around 2.880 I think

Cannot really go for what is "ideal'' or what factory settings are. Too many manufacturers in the world with different machines grinding these things out. If you open the backlash a few thou it may fall into place

Dleslie212 08-25-2020 09:26 PM

Re: Contact pattern
 
Quote:

Originally Posted by kwmech (Post 8798052)
Cannot really go for what is "ideal'' or what factory settings are. Too many manufacturers in the world with different machines grinding these things out. If you open the backlash a few thou it may fall into place


Here is the latest pattern as of five minutes ago. Depth is the same as before. Backlash is now at 006, that's closest I can get it to the 7-9 with the shims I have. My previous backlash was at 011, not the 004 I had told you before. So I tightened from 011 to 006 since the last link

Edit - I can do either 011 or 006 on the backlash. I figured tighter would be better. The previous pic link was at 011, the link below is 006

https://imgur.com/gallery/ynk6abR

kwmech 08-26-2020 01:38 AM

Re: Contact pattern
 
I'd say that's a keeper. Little tight on the back lash, but it will loosen up a little after everything breaks in. Do you have decent bearing preload on the carrier?


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