Phosphorous coating on differentials

[dailydriver]

Originally Posted By: JohnBrowning
This research was down in the 1960 and 1970's but other then Toyota all the Domestics are making their Ring and Pinons the same way they have for ever. They do not lap them much either.


I know for a FACT that the AAM made GM OEM ring and pinions ARE lapped (and heat treated, and cut properly).
If they did not, they would scream like banshee sirens (even with proper setup), and every one of them would be back in the dealers for warranty work!!

 

[PT1]

Originally Posted By: dailydriver
Originally Posted By: JohnBrowning
This research was down in the 1960 and 1970's but other then Toyota all the Domestics are making their Ring and Pinons the same way they have for ever. They do not lap them much either.


I know for a FACT that the AAM made GM OEM ring and pinions ARE lapped (and heat treated, and cut properly).
If they did not, they would scream like banshee sirens (even with proper setup), and every one of them would be back in the dealers for warranty work!!


AAM has had lots of warranty work in the past 5 years on their diff gear sets failing...especially the front ones. I know...I had one go bad in 40k on my Denali. The dealers said about 1 in every 3 was bad. Then refused to warranty it. That did it for me with GM. But Toyota is not much better. On many of their SUV products the rear diff ring gears are too small for the weight & power of the vehicle. Many of them are whiny as well. Toyota has so may whiny ones they have a swap out program for the complete 3rd member now versus rebuilding them at the dealer.