8.8 Gear Contact Pattern

[bamfslap]

I am putting an Explorer 8.8 into my Ranger with 4.56s. I am having trouble reading these patterns. The backlash was set within spec with a dial indicator. I used a pry bar to "load" it while testing.

What is weird to me is that the mark ends suddenly midway in a perfect line. Any ideas?

EDIT: Better pics.

 

[BLOODBANE]

Back up and take a little better pic. Kinda hard to register all thats going on in those pics. (you dont need to be right on the contact pattern)...

 

[bamfslap]

Will do, it was at night so the light would cast a shadow.
EDIT: Uploaded some better pictures to the original post. My phone's camera really sucks. Apologies. I resized them.

 

[Captain Ledd]

Those are a lot better. I too had some trouble orientating myself looking at the original pics.

I'd say your pinion is a little on the deep side, might want to back that off a bit but not much. Otherwise it looks fairly centered. you're definitely on the right track.

 

[bamfslap]

Awesome, thank you. So I should add a shim. edit, actually too deep would mean take one out.
.
This is my first time re-gearing. Sounds weird, but it's actually pretty fun!

 

[bamfslap]

Removed .01 shim
Backlash is at .008
Better camera.

 

[bamfslap]

Messed with the pinion depth a little more. I feel like I am really close now.
Backlash at .010.

 

[4x4junkie]

I think that looks pretty darn close... though the pattern still doesn't seem as clear as I think it could be.

Try loading the pinion, and then rotate the ring gear to get your pattern (use a wrench on a ring gear bolt to turn it). For me this invariably made a much higher-contrast pattern on the gear teeth.

 

[bamfslap]

How do you recommend loading the pinion? (The axle is out of the truck)

 

[Captain Ledd]

Two hands, one with a wrench on the pinion nut, the other turning the carrier by a ring gear bolt.

 

[bamfslap]

Oh, that should be easy. Before I was using rags + pry bar. lol

 

[4x4junkie]

Or just stick a deep socket in the pinion yoke, and grip it while turning the ring gear.

 

[bamfslap]

Been a busy week but I got some more done. Same shims, pinion depth backlash (.010), etc. I set the preload to 23 in. lbs and tested it with the socket method.

With new bearings, races and preloads set it's pretty tight to turn the ring gear by hand heh.

 

[4x4junkie]

Yeah if all the bearings are brand new, it should be fairly stiff to turn.

I'd say that pattern looks good, go ahead and button 'er up.

 

[bamfslap]

These gears are ****ing amazing! Even with the 3.slow it feels peppy again. No noise either. Just smooth torquey goodness. With the aftermarket diff cover (more capacity and higher fill plug) it took over 1.5 gallons of oil to get to the plug! The breather hose puked up a little, but not much. The Explorer's softline T is on the drivers side while the Ranger's is on the dif. Is it too short to flex with a 6" lift?

Now I've got to do the front dif asap!