Quote:
Originally Posted by FSETH
I found this post from JCL in one of the numerous trans fluid threads...
On higher mileage transmissions it isn't the metal shavings you have to worry about, although there could be some. If you have metal shavings, it doesn't really matter if you change the fluid or not as the transmission is likely on its way out. What wears inside a transmission are the clutch packs (multi-disk wet clutches) and the bands; both are surfaced with a non-metallic friction material that wears over time. That material is what can clog a valve body. It sits there undisturbed but can be moved by a fluid change. Clean fluid doesn't dissolve it, but draining the fluid and then starting it up and repressurizing the clutch packs can move it around. It may not happen, but in any case that is the theory behind the risks of changing fluid on high mileage transmissions.
I am going to jump off the JCL train now.  I am not saying this is going to happen, but I guess I wouldn't call it a non-issue either. |
I previously acknowledged the possibility of disloding sediment. However my personal opinion, and it appears it is shared by JCL, is the possibility of it happening is very low. Furthermore should sediment be dislodged I have seen no evidence it will result in a transmission failure. So the chances of dislodging sediment are very low and the chances of dislodged sediment resulting in a transmission failure are very low.