So I am done with my Auto Rx dose in my transmission. Vehicle is a 4x4 Yukon with the 4L-60 tranny. I am still trying to decide which AT Fluid to use. At the time I am leaning towards Redline fluids. So I asked Dave at Redline and he recommended the D4. I asked him why and he just said either would work but the viscosity of the D6 is as thin as a sheered Dino tranny fluid. He also recommends it because it is what the original spec was. However GM is now recommending D6 in this tranny. So what does everyone here think I should go with? TIA
Redline D4 or D6?
- Thread starter mcrn
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Stick with daves recommendation. I have used D4 in three 4L-60 transmissions and have never had any issues. The D6, if you read the specs, is a lower viscosity shear stable fluid meeting Toyoyas new WS spec along with Mercedes Benz NAG-2,Ford Mercon SP and requirements of Dexron VI. Both D4 and D6 are GL-4 rated fluids as well. The higher viscosity of the D4 as Dave has stated will work better in your 4L-60 trans since the original spec fluid for that unit was already a more viscous fluid to start with. You will love Red Line ATF. One of the best out there.
I have a 4L60 in my Yukon that is speced for DEXVI so I use it. It is the 4th 4L60 I have owned and shifts better with the DEXVI than the DEXIII did on the other 3. Why don't you get Castrol or Coastal DEXVI at autozone for 1/2 the price of D6? All approved DEXVI fluids that are on the GM approved list are synthetic. BTW D6 is NOT on the list as far as I know. So why would you spend twice the money on a non-approved fluid?? Supertech DEXVI is also approved and is $3qt. Just saying.
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I have seen the Castrol DEX VI, and it clearly says "Synthetic blend" on the bottle.
Anyway, Redline D6 contains PAO and Esters, basestocks that are even more durable and with a higher VI than the Group III that is in most Dexron VI oils.
Anyway, Redline D6 contains PAO and Esters, basestocks that are even more durable and with a higher VI than the Group III that is in most Dexron VI oils.
Nobody said that DEX VI couldnt be used, we mearly stated that D4 would be the best ATF for this application offered by Red Line Oil. And you have to go get into the paranoid "non-approved" fluid nonsense. He already has expressed his desire to use Red Line. Coastal or Castrol??? PLEASE.
I tried Redline D4 and Redline D6 in my wife's 2003 Honda Accord. I posted the results of the D4 in used analysis compared with a run of Amsoil ATF previously. D4 worked better in the Honda Transmission. I ended up draining the D6 and adding D4 with platinum lubeguard. Car is shifting excellent again. I think the D6 would be appropriate for your transmission, and I like the fact that the flashpoint is higher at 480 degrees F.
My 2005 Sequoia came from the factory with Toyota WS. Redline's replacement for WS is D6. However, because of the slightly higher viscosity, I originally chose D4 and it worked perfectly. I now have D6 in it and I can't tell the difference. Fuel mileage will probably be ever so slightly better with D6. However, the way I drive my Sequoia (frequent WOT), I'll never know.
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