I have a concern about a slight over-fill of the trans. I just changed the spin-on filter. I filled the new filter with fresh M-1 synthetic fluid and re-installed it. I had a drain pan under the spin-on location to catch the fluid that drained out after the filter was removed.


There was a half quart in the drain pan, so I added a half quart to the trans to make up for the fluid lost. I drove the truck until the trans temp was about 170*, then I checked the fluid level. It was almost a quarter inch above the highest mark on the "hot" portion of the dipstick. Prior to changing the filter, I checked the fluid level and it was just below the highest mark on the hot portion of the dipstick.


Should I be concerned that the trans is slightly over filled?

Yes you should be concerned aout being over filled, if it gets high enough it will cause havoc and probably nuke your trans in short order. Now how high is too high? Well your probably not there yet but with it so easy to drain why chance it? JMO

I agree with ratlover. Sometimes that quarter inch is 2 qts. I keep mine ( and my customers) just below the top mark at operating temps. The main reason not to overfill is if the fluid level reaches the planetary gears, the gears begin to churn the fluid ( planet gears are lubricated by spray or drip) and that causes air bubbles in the fluid. That means you have half air and half fluid circulating through and that does not lubricate well,


mike

Dura-Mike, The first time you do a hard pull in hot weather it will puke fluid all over the bottom of your truck, BTDT. It needs to be about 1/2 qt below full at normal operating temp.http://www.dieselplace.com/forum/smileys/Cry.gif