tranny fluid???

[ff_jeff]

Ok I have heard that synthetic is bad for the 4l60. if this is true redline makes atf fluid and som is synthetic, others are high heat and such, is there any benifit from getting expensive fluid? has any body tried it? google redline oil and look in 247parts not redlines site.

[Slimsilverado]

I have run Mobile 1 synthetic for the last 57k miles in my trans with no real major problem, but now that my truck has 107k on it i do get some slip from time to time. So im going to change it here in a few weeks to some Valvoline high mileage formula along with some Lucas transmission fix until i can rebuild this trans or get one from FLT

[foggy]

FLT recommends standard fluid in their units.

[DamnYankee]

What I've been told is you want to use standard fluid. Synthetics often act too well as a lubricant in a transmission, whereas standard fluids will help the "grip" in clutch packs etc.

[COWL327]

+1