Low Idle In Reverse

[GCP]

Hello everyone,

I have a 68RFE and 82,000 miles on the odometer. When I put the truck into reverse the idle RPM drops from a steady 1200 RPM to about 1050 RPM. Also, this condition occurs every time with the exception of first thing in the morning if the ambient temperature is in the mid to high 30s and lower.

One other thing that may or may not be related. Lately, the transmission stays in 5th gear for an extended period on cold mornings before shifting into 6th.

Is is the low idle in reverse and the delayed shift from 5th to 6th when cold normal? If not, what might the problem be and what solutions might you suggest?

Once again, thank you all for your wisdom and assistance.

Best,

GCP

 

[transe]

Both are normal. Reduced idle speed in Reverse is done to reduce the driveline torque at idle, which in turn reduces the clunk you can get when shifting out of Reverse. Trans will not shift to 6th gear until the Torque Converter Clutch (TCC) engages, and TCC will not engage until the sump temp reaches a certain level (80°F, I think, but my memory could be wrong).

 

[GCP]

Both are normal. Reduced idle speed in Reverse is done to reduce the driveline torque at idle, which in turn reduces the clunk you can get when shifting out of Reverse. Trans will not shift to 6th gear until the Torque Converter Clutch (TCC) engages, and TCC will not engage until the sump temp reaches a certain level (80°F, I think, but my memory could be wrong).

TransEngineer,

I was was hoping to hear from you! For some reason I don't remember my '09 dropping to such a low idle while in reverse. But, now that you mention it, I do recall the delayed shift from 5th to 6th. Once again, I'm grateful for the wisdom that can be found here on TDR.

Best set wishes to all,

GCP