Discoloration normal? Rear differential pinion gear

[AZRedneck]

Not sure if this discoloration is normal between the teeth on pinion gear? Truck didn't seem to be shifting properly pulling 28ft toy hauler on big hills. Trans temp always seemed normal. Just changed the rear differential oil at 17000 miles with AMS Severe Gear 75-90 and seems to be shifting smooth again. Auto with 68RFE 3. 73

 

[HBarlow]

Discoloration looks like previous water intrusion caused rust.

There is no possible connection between automatic transmission shift patterns and differential ring and pinion issues.

 

[NIsaacs]

It might just be the stain from "persian blue" or whatever they use for pattern check. I used "white Lead" back in the day before it was outlawed.



Nick

 

[Hoefler]

It might just be the stain from "persian blue" or whatever they use for pattern check. I used "white Lead" back in the day before it was outlawed.



Nick

Looks good to me. I have used the Persian blue to set many a gear set myself.

 

[MChrist]

I took a pic of mine 2 weeks ago, and it looks EXACTLY like yours!! Either no problems, or we both have bad gears. .

And the only way the ring gear would have any impact on shifting, would be if there was so much friction, it would keep the truck in gear longer to overcome that friction. If there was THAT much friction, it would be like driving with the parking brake on!! And your gears would look like melted blobs of welding slag!!