Pattern opinion

[jeepthrills01]

So 489, new bearings, crush eliminator, auburn LS, new US Gear set, B/L is .006 to .0072 (I checked every dang tooth..FML).

Thoughts? Thanks!

 

[AR67GTX]

From my limited experience and my reference photos last year setting one up I would say your pinion depth is too great. I would try reducing your pinion shim about .006 or .008” and see what difference it makes. But I’m a novice so lets see what some of the others say.

 

[MarPar]

@Cranky

 

[Cranky]

I've never been that great reading the pattern but go by my setup tool. So far so good with that and once I get the numbers for the pinion depth, I set the backlash and go and the pattern never looks right to me....so far, nothing but quiet gears. That said, I agree with AR67 about pulling out a few.....and .005 should give a better looking one. Hope you're using a 'dummy' (trial) bearing to make things easier.

 

[jeepthrills01]

I've never been that great reading the pattern but go by my setup tool. So far so good with that and once I get the numbers for the pinion depth, I set the backlash and go and the pattern never looks right to me....so far, nothing but quiet gears. That said, I agree with AR67 about pulling out a few.....and .005 should give a better looking one. Hope you're using a 'dummy' (trial) bearing to make things easier.

If I was still in Houston I would have just come by..but Im back in AZ.
And yup...set up bearings on the pinion!

 

[dvw]

Pinion is way to deep.
Doug

 

[AR67GTX]

When I set up my 489 last Fall I made some set up bearings and ran probably 20 some trial set ups with different pinion depth and backlash and took pictures of each pattern. I don’t know if this is always true but I experienced that the drive side pattern would hold up over a wider range of pinion depth than the coast side. On the drive side it would vary up and down from the toe to the heel as I changed the pinion depth, but the imprint pattern didn’t vary a lot and it stayed out of the root and crown for a pinion depth range of around .010”. But the coast side imprint pattern would only hold up over a range of about .007” before sliding off on the crown or into the root.

And the ranges for coast and drive did not exactly coincide. The acceptable patter imprint for the coast side was over a shallower range of pinion depth than it was the drive side. So I kind of had to focus on where the acceptable tooth imprints/patterns overlapped.

I didn’t find that backlash made a huge difference as long as I stayed around the .006 to .010 range.

I don’t know if this is typical or even good guidance. The experienced guys see small details in these patterns that it takes years of experience to recognize. I had problems getting as good a quality of pattern imprint with the yellow grease as many guys were used to dealing with so a lot of the feedback was - try to get a better imprint - something I never fully succeeded at. But I had had two shops try to set up gears in my 489 earlier and both has failed. I took photos of their work before installing the center for a try. In going back over their pictures and comparing to mine, it looked like they both concentrated on the drive pattern and just blew off the coast side. But I still have some of what DVW described recently as float whine so there’s that.

Long post - kind of like a Seinfeld episode - about nothing.

 

[Cranky]

When I set up my 489 last Fall I made some set up bearings and ran probably 20 some trial set ups with different pinion depth and backlash and took pictures of each pattern. I don’t know if this is always true but I experienced that the drive side pattern would hold up over a wider range of pinion depth than the coast side. On the drive side it would vary up and down from the toe to the heel as I changed the pinion depth, but the imprint pattern didn’t vary a lot and it stayed out of the root and crown for a pinion depth range of around .010”. But the coast side imprint pattern would only hold up over a range of about .007” before sliding off on the crown or into the root.

And the ranges for coast and drive did not exactly coincide. The acceptable patter imprint for the coast side was over a shallower range of pinion depth than it was the drive side. So I kind of had to focus on where the acceptable tooth imprints/patterns overlapped.

I didn’t find that backlash made a huge difference as long as I stayed around the .006 to .010 range.

I don’t know if this is typical or even good guidance. The experienced guys see small details in these patterns that it takes years of experience to recognize. I had problems getting as good a quality of pattern imprint with the yellow grease as many guys were used to dealing with so a lot of the feedback was - try to get a better imprint - something I never fully succeeded at. But I had had two shops try to set up gears in my 489 earlier and both has failed. I took photos of their work before installing the center for a try. In going back over their pictures and comparing to mine, it looked like they both concentrated on the drive pattern and just blew off the coast side. But I still have some of what DVW described recently as float whine so there’s that.

Long post - kind of like a Seinfeld episode - about nothing.

New gears always come with a pattern sheet and there's also plenty of them on the internet to look at. What kinda surprises me is the 'acceptable' patterns looks kinda all over the place. I'm just glad I have a good set up tool. When I first got it and after setting up my first set of gears, the pattern just didn't look like what was listed on the sheet. Keep in mind that there wasn't any access to the internet for me back in the late 80's. Anyways, stuck my first setup into my 71 Cuda and went for a ride breaking them in and after several hundred miles, it was still quiet.....and did that for the next 3 setups! After that, didn't even bother looking at the pattern and just trusted the setup tool. Problem there is when ya get a set of gears where you can't read the + or - on the head of the pinion gear. When that happens or when setting up a stock set of gears (they are not marked), you go by the mounting distance which isn't so easy to measure AND check the pattern to confirm.

 

[dvw]

I don't use a pinion depth tool. I find them inaccurate. If it doesn't fall off the edge ofthe crown or root it's probably going to be good. Heel and toe really don't make much difference. The more power you make, thr looser you set the backlash. Drag stuff .010"- .p
012".
Doug

 

[jeepthrills01]

I finally had some time to screw with it...

Final result IMHO....Thoughts?
Drive side followed by coast.

 

[jeepthrills01]

No opinions?...Buller? Lol

 

[AR67GTX]

Well, I think it’s much improved but it would help if it was a little bit clearer tooth pattern. Can you put some fresh gear paste on it on and re-roll the pattern and put as much drag on the gears in both direction as possible to build some tooth contact resistance.

 

[jeepthrills01]

I'm out of yellow stuff...local stores don't carry it.. FML.. it had plenty of resistance... had to use my half inch titanium gun to spin it! Lol...

Waiting on jungle delivery for more paste

 

[AR67GTX]

I think I got some through Amazon.

 

[dvw]

The pattern being a little dry makes it a little tough to see. But it looks pretty good.
Doug