Anyone using synthetic trans fluid? Thinking of changing over to Mobil 1. Comments/experiences welcomed!
The tranny people that I have talked to say to go with DexIII on sale and change often. According to them fresh fluid is better than fancy fluid.
I've quizzed performance trans rebuilders on this subject in the past and 3out of 3 of them said don't use it. Unfortunattely I don't remember the reason. A bad reaction to something inside there. Clutch paks or something. I just know I took their word for it and don't use it.
I've been using Red Line D4 full synthetic for years with no problem whatsoever. I know TCI recommends synthetic in their Hi-Po transmissions. Synthetic oil will stand up to heat better, which is the downfall of any automatic.
I switched over to MOBIL 1 synthetic in the turbo this summer before Nationals..............shaved off 2 tenths. I've heard don't use synthetic before, but none of those guys could site any specifics..........sounds like a bunch of b.s. NO PROBLEMS with synthetic to speak of.
I had slippage problems with Amsoil synthetic (too slippery?) but now run a mix of type F and RedLine RACING synthetic (50/50). Seems to get most of the synthetinc benefit w/o the high cost.
When I changed my switch pitch converter, I drained the pan also. I figure I had to get at least 95% of the oil out. Refilled it with 10 + quarts of the Red Line Fluid. Doesn't matter anyway, by law, all oils must be compatible. I don't believe any of those tales about synthetic ruining transmissions.
I just dropped the pan, my tranny had 138K miles on it. It started shifting soft 2 weeks prior to nats. It appeared previous owners never changed fluids or filters!! Previous fluid looked like motor oil. I switched to synthetic and changed the filter. Shifts tightened up and gained 2 tenths. 2K miles later no problems. I'm going to put the car away for winter in the next 2 weeks and start on another project. I'm going to have all the fluid sucked out in the spring and go 100% synthetic. I am pleased with the performance and I know Don Eggers who encouraged me to switch hasn't had any problems. DK
We run synthetic fluids everywhere in our race car, tow vehicles, street cars, lawn mowers and pencil sharpeners. We use it and we LIKE IT!!
