Increased driveline noise with Red Line MT-LV Oil in Transfer Case

[rsachek]

I recently changed the transfer case fluid in my 2020 5th Gen Ram 1500 with the BW 48-11 "4-Auto" transfer case. Based on comments in forums like this, I decided to go with Red Line's MT-LV gear oil which is more readily available than the OEM Mopar fluid (reportedly repackaged MobilFluid LT) and less than half the price of the Mopar stuff. Red Line says that MT-LV is a suitable substitute for Mobilfluid LT, but right away, I noticed a subtle moaning/creaking sound when driving in reverse. Then, driving in deep snow, I heard similar creaking and chattering in 4wd high. I have owned this truck for almost 4 years and 50k miles and never heard noises like this from the t-case before using the Red Line fluid. Long story short... I switched back to the Mopar fluid yesterday and all of the mystery noises are gone. I know that some folks had good results with the Red Line MT-LV but personally, it scared the crap out of me.

 

[392DCGC]

I'm sure you filled it to the proper level, but interesting this gave you an issue. I was planning to change mine in the spring time when I'll be around 60K miles and was going to use Amsoil SS ATF, but now I may reconsider that.

How did the factory fluid look when you drained it?

 

[rsachek]

The old factory fluid looked like new. I did the front diff, rear diff, and transfer case all within a short period of time and visually, only the rear diff fluid really looked like it needed changing. Believe me, I wanted the Red Line fluid to work out. I like saving money and supporting American businesses, but instead wound up dumping ~$50 worth of one week-old oil into my recycling pan. The factory fluid is stupidly expensive (two quarts from Mopar costs the same as a 5 gallon bucket from Mobil) but like they say, "buy once, cry once."