re: Brought my truck in today for oil/tire rotation & dealership called suggesting

quote:

---

transmission service: $211

---

Depending on what this entails, there's a chance this could actually damage your transmission. This is especially true if they're going to do a transmission "flush & fill". Here's as good of an explanation as I've found on why you don't want to do this....

quote:

---

The only ones who do recommend flushing as a maintenance procedure are the companies that sell the flush machines and the shops that buy them. The flush machine manufacturers state quite clearly in their operating manuals not to use their machines on "high-mileage vehicles". That simple statement proves that flushing is not a safe procedure. It also absolves them of any responsibility of any damage that may occur due to the use of their equipment. This leaves the shop wholly responsible for anything that happens and the cost of correcting the damage that occurs.

The Dangers Of Flushing...

Flush machines do what they say; they force high pressure cleaning solvents back through the engine and transmission and clean out some of the accumulated junk that has formed. Now engines have small passages and galleries through which oil or automatic transmission fluid flow and there are one-way valves that keep the fluids from backtracking for whatever reason. By using an aggressive cleaning procedure like flushing, large chunks of accumulated sludge are broken off and forced backwards through these galleries and valves and, more often than not, lodge tightly and block them. This cuts off the normal flow of the fluid and causes lack of lubrication in an engine and abnormal or no shifting in a transmission. The results are expensive repairs, or more often, engine or transmission replacement.

---