SD60 Gear Pattern Check

[MtnYota]

What would the new forum be without a gear pattern check thread!

Specs
2006 F250 D60 Spicer 5.38 10" gears installed on a yukon grizzly locker

Pinion set with 0.034 shim under the inner pinion bearing race backlash is at 0.007 and the case preload just so that takes a wack or two to get the case in. Pinion preload not set and this is using setup bearings.

Let me know what you guys think.

 

[MtnYota]

So I found out that the Spicer gears are face hobbed or "2 cut" gears and that they end up with a different pattern. That is why the drive size pattern appears angled. But I can't seem to find any 2 cut backlash specs for the D60.

I found this page that talks about how the pinion depth and backlash move the pattern around on the 2cut 8.8 gears.:
https://www.diyford.com/ford-axle-ri...ssembly-guide/

 

[EndlessMtnFab]

Hard to say. The top tooth of the first pic (coast side) seems to be heavily slanted towards a triangle, rather than typical parallelogram that the 2 cut favors.

Drive side seems to straddle between triangle/parallelogram to my eye. What happens if you over-under size the shim (shape wise) ?

 

[MtnYota]

These are @ 0.044 pinion shim and 0.006 backlash. This attempt was before I realised they were 2 cut gears. Apparently they like more backlash, but I can't find any specs still.


I kept going shallower with the pinion thinking the hard line on the coast side meant I was too deep like with 5 cut gears, but now I am wondering if the 2cut's show a more defined line and that is a shallow pattern on the coast side. I'll make a couple more attempts tomorrow.

 

[EndlessMtnFab]

I recall the 2 cut preferring LESS, not more.

But I've been wrong from time-to-time.

 

[EndlessMtnFab]

https://www.differentials.com/two-cut-vs-five-cut-gears/

 

[MtnYota]

Here is 0.042 and 0.012" BL

Here is 0.050 and 0.008BL

​

I think I need to pull the pinion back out a little and tighten the BL a little. Below is what I am basing the corrections on. It seems a little different the adjusting the 5cut gears.

 

[MtnYota]

Here is 0.046 pinion shim and 0.006BL

​

Here is 0.044 at 0.008BL

​

I'm thinking about running with this last one and trying to tighten the BL up to 0.006 what says the great PBB... or IBB?

 

[KarlVP]

I like the last one the best. .046 at .006 bl. You are much more down at the root of the gear where the strentgh is.

 

[Action Fab]

It's good. Run it.

 

[EndlessMtnFab]

I'm in agreement. Last pattern looks the best (esp coast side)

 

[MtnYota]

Thank you guys! Time to button it up.

 

[dentedsub]

Instead of starting a new one, I'll add to this. Its a 44 not a 60 but I figure close enough.
How's this look? They are cheap richmond 5.13s.
What causes the line that I circled. I didn't see that in the first couple patterns I pulled.