Tremec Hi Performance Transfluid in T56

[RetroJonez]

Hey All,

So finally have the car running great (1998 GTS) had a bunch of problems if anyone remembers. Last summer I replace the transmission fluid with Tremex HP MTF. Looked good for the T56. https://www.tremec-store.com/collect...smission-fluid

Then last weekend I started noticing some rattling marble sounds at idle, barely touch the gas, goes away. Goes away slightly with clutch depressed. I am assuming this is the common neutral gear rattle.

That said, I never had it prior, and I came across this press release from tremec. https://www.tremec.com/not_am_detall...mission-fluid/

"1-quart bottles of HP-MTF indicate that the product is recommend for assemblies manufactured from 2008-to-present. This is due to crossover considerations related to various OEM programs for which we cannot guarantee compatibility—namely the “carbon paper” friction rings commonly found in early T-56 transmissions. TREMEC has NOT validated the compatibility of HP-MTF with this material."

Im not sure why it says carbon paper rings. I thought it was either carbon or paper, should I drain it and replace it? Dodge dealership said their fill is now Mopar ATF+4. I don't want to start the heated transmission fluid debate, but assuming I should get this fluid out of there? Then ATF+4 sound good? or is something else now the go to?