: Transmission fluid

09-09-11, 05:46 PM
Well I hit the century mark on my STS & I have heard a lot of conflicting views on what to do with the transmission fluid. I have seen some people say to drain, flush & refill, just drain & no flush, & to not do anything if you are not having problems. What do you guys think the best thing to do is? I changed the coolant a few months back when I hit 5 years (I also changed the belts) & I know I will also have to change the plugs. Any other preventive maintenance I should do?



09-10-11, 09:38 AM
Personally, I would change it out. I had a Benz a few years ago ('98 E320) that shifted sluggishly around 115K miles. A fluid and filter change (required dropping the pan) made a night and day difference in the responsiveness of shifts, etc.

No fluid or filter lasts forever. At least on my '05 STS, the transmission is exceptionally liberal with gear changes. It's a hunter and I imagine that doesn't help fluid life.

I'd change it.

09-10-11, 12:13 PM
Good logic, Maximln!

Every shift introduces particulate matter from the clutches. Sure, not much, but some.

The PO of mine said he had it changed @ 50K, so I'm going to change it at 100K, with a filter, and the most complete change I can perform.

Might be earlier, as I just realized 13K additional miles puts me at July-August 2012. Erk.


09-10-11, 02:05 PM
I recommend taking it to the Cadillac dealer, they have special machines for the radiator, AND the transmission
to drain, flush, and refill. yes it costs a little more, but it gets done right.
Have Fun, Good Luck !