EatonTransmission

[RichM]

Just wondering if anyone has ever experienced this problem with a Eaton/Fuller 6 speed.
When the outside temperature is over 90 degrees and the truck has been running on the road for some time ,the transmission is real difficult to drop down out of 6th gear.It goes up all the way and down from 5th to 1st with no problems,but is very hard to get out of 6th. When the temperature cools down at night or if a rainstorm comes along it works normally,seems like something must be expanding in the heat but I don!t know what. I was in upsate NY last week in Lake Placid (try delivering there sometime in the daytime) and the transmission shifted like new,but it was 60 degrees,home here in the south it binds real bad.Hope Weave sees this post before the Freightliner dealer gets me into involuntary servitude.

 

[Weave]

It does sound like an internal problem with something expanding too much like you said. But, try these two things before getting it rebuilt. First, replace the shift pin on the end of the shift lever ,the thing that looks like a little boat oar. It might be badly worn in the position it's at when you downshift out of 6, especially because it moves around there a lot while driving. You can probably tackle that job yourself if a dealer has the part in stock. Just put 'er in a gear and undo the 4 9/16 bolts that hold the lever on. Watch the gasket. I think the pin itself is held in with allen screws.
Next, replace the fluid with synthetic. Eaton and the others are using it in all their new trannies as it is less sensitive to temperature changes esp. hot.
See if these things help it.
-Weave-