changing to synthetic

[jmac5058]

Is the reason for changing to TD for longivity or better milage or both and would it go into transfercase also.

[bigdaddydiesel]

Yes to all of the above. You can get longer intervals from TD, as well as better mileage, although the Low Viscosity ATF we now offer does as good if not better with mileage in testing, and it CAN go into the Transfer Case. there are those that have turned away from tranny fluid of any kind in the transfer case and started using 5w-30 synthetic motor oil with good results as well though. But Torque Drive will be just fine in your transfer case, it is in mine now and has been for a year without issue.

[jmac5058]

Just how do you thank someonein a thread.

[bigdaddydiesel]

Simply thank them, most will see it. But also, you can go to their section of the forum and start a new thread to thank them...

[45Colt45]

"The Myth" that you guys speak of is not a myth, but it is not really applicable to a transmission. The myth is mainly used for engines, or traditional automatic transmissions where if you pull out the tail shaft the fluid pours out. The thougth process is simple, the synthetic fluid has smaller and more evenly sized particles/molecules, not to mention that it generally contains detergents or cleaners that are designed to keep the engine/tranny cleaner, cooler, etc... So if you have parts expanding and contracting around gaskets for 100K miles there is a pretty good chance that the tolerances will not be as they were from the factory. Generally standard fluid and oil will plug these gaps (that's why, generally, when you look at some older engines you will see around the oil pan or valve covers where there is a little leak but it is covered in dirt/dust and it usually never physically leaks out on the garage floor). In steps synthetic, with all its smaller molecules and cleaning detergents; while doing its job, it will usually frees up these deposits that are pluging these gaps and leaks will start.

CASE IN POINT:
This has just happened to me, bought my first duramax in July with 96K on it, "with no oil leaks", came with all service records and oil was changed every 3000 miles with standard oil. I switched over to Schaeffers synthetic and went to 4000 mile oil change cycle, yesterday I had the oil changed for the second time since I have owned it. Today I was checking the trans ID tag, and low and behold I now have a leak from the rear portion of my oil pan, and I can see where it is starting to leak at many points around the pan. At the same time I switched over to dextron VI and have had zero issues with the trans.

Just and FYI

[sibittwi]

No, you're supposed to reuse it. Anyway, the Allison dealer can get you a new one, or the dealer. Be sure not to forget to reuse it when you service the filter on your trans!