Gear tooth pattern question

[Isualumnus]

I installed new ring and pinion gears. My backlash is within spec. This is the pattern I am getting. The ford instruction sheet shows ovals but it appears I have contact across the whole tooth. Here are some pictures of drive and coast side. Are they good or do I need to adjust pinion depth? If so thinner or thicker pinion shim?


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[Midlife Crises]

Optical illusion is messing with my eyes big time but I think you need to add more pinion shims. I see a damaged tooth. Have these gears been run before?

 

[TerryZak]

My son and I rebuilt his 2010, 7.5" back in November. Agreed that looking at the pictures tends to make one go cross-eyed after a while, but it appears to me that the patterns you're showing are the "coast" side. From the angle, I can't get a look at the drive side, but the pattern does appear to be too "deep", as there the indication runs right down to the base of the tooth profile.

Based on the PDF I'm going to try and attach, it appears that your pinion is too deep, and that you need some additional shim to adjust.

Here is a picture of the "as-found" pattern from this rear; prior to disassembly. I'll note that there was no preload on the pinion, as the bearings were quite worn out.

 

[TerryZak]

Here is a picture of the as-assembled patterns with specified backlash and preload.

 

[TerryZak]

Correction!! From the picture that you posted, the first few teeth on the left side are all I can go by, and they look like the pattern is TOO HIGH on the teeth, meaning TOO much shim. Try to show pictures a little better if possible.

 

[Rick Simons]

My patterns looked almost exactly like TerryZak's, if that helps. I installed FRPP 3:73's, and used the original rear pinion shim.

 

[Mustang Terlingua]

Do Y'all have access to the factory or aftermarket pinion depth gauge in the shop manual. If not it is trial & error thill Y'all hit it. Then Y'all take into account Backlash change & have carrier shims & remember case spread or bearing preload. Tools & Experience are expensive in the beginning but pays off in the long run. Yes I are old & did it caveman style & bought the Ford OEM depth gauge used & have used it for 30 yrs.

 

[TerryZak]

I agree that the factory tools would be helpful. However, I purchased the "GXL Carrier & Pinion Bearing Puller Dana 30, 40, 60, 70, 80, Ford 10.25 Clamshell Design" on Amazon when it was $220; it's now down to $129 which is a steal. Makes pulling the pinion and carrier bearings a breeze, and since it's so easy to remove the inner pinion bearing, then a trial-and-error approach is not too bad.

For me, since I kept the same gearing I didn't need to change the pinion shim, but double checked everything just to be sure.

 

[Midlife Crises]

Removed Ford 373s and installed Yukon 430s with original pinion shim.

 

[GlassTop09]

I agree that the factory tools would be helpful. However, I purchased the "GXL Carrier & Pinion Bearing Puller Dana 30, 40, 60, 70, 80, Ford 10.25 Clamshell Design" on Amazon when it was $220; it's now down to $129 which is a steal. Makes pulling the pinion and carrier bearings a breeze, and since it's so easy to remove the inner pinion bearing, then a trial-and-error approach is not too bad.

For me, since I kept the same gearing I didn't need to change the pinion shim, but double checked everything just to be sure.
View attachment 82318

I got the exact same setup myself to use when I swap out my gears soon. Was the same $220.00 when I bought as well.