Occasional Harsh 5-4 and 4-3 downshift on 2011 Eco
07-03-2011, 07:01 AM
#21
I just test drove one and noticed the same thing. Made me think twice about buying it.
07-04-2011, 05:15 PM
#22
Senior Member
Thread Starter
Seems many Eco's are doing this. I had a friend get in (foot on brake) and shift the transmission select from reverse to drive (back and forth) while I looked at the drive line. One thing I noticed is a poping/clicking from the rear end and seems as though it has play back there. I think this might be what is manifesting itself as the harsh downshift. Mine seems to do this when there is no load on the drive line and then when the downshift happens, the load shift (combined with the aforementioned play) is what causes the bump/thump in the shift......My theory. Anyone else notice the same?
Last edited by HogFan; 07-04-2011 at 08:23 PM.
07-04-2011, 09:53 PM
#23
Yup. I am starting to think that this is the way the 6r80's are going to be. I know Ive been through a few T3650's and they were loud and clunky. I'm sure they are going to have to come up with a update flash for these tranys for smother shifts. We can only hope.
07-04-2011, 10:37 PM
#24
Senior Member
looks like i'll have to take mine in to the dealer for a reflash. Hopefully that will solve the problem, if not, then Id hate to leave it there for a longer period of time.
Mine only has 1800 miles right now. but noticed the problems since it was at like 200-300
Mine only has 1800 miles right now. but noticed the problems since it was at like 200-300
07-10-2011, 10:13 PM
#25
Seems many Eco's are doing this. I had a friend get in (foot on brake) and shift the transmission select from reverse to drive (back and forth) while I looked at the drive line. One thing I noticed is a poping/clicking from the rear end and seems as though it has play back there. I think this might be what is manifesting itself as the harsh downshift. Mine seems to do this when there is no load on the drive line and then when the downshift happens, the load shift (combined with the aforementioned play) is what causes the bump/thump in the shift......My theory. Anyone else notice the same?
Last edited by Skandocious; 07-12-2011 at 01:00 AM.
07-11-2011, 10:44 PM
#26
Senior Member
Thread Starter
Just created a new account so I could bring more attention to this post. I did the exact same test earlier today and was very concerned about the amount of play I was seeing at the rear axle pinion. I know it's normal (and expected) to have some play, otherwise the gears would hum, but it seems excessive to me. I sometimes very a very harsh slam when shifting from D->R or R->D and now I have figure out why.
I looked at this again this evening and I honestly cannot tell if the play is in the rear end or the transfer case. I locked mine in 4X4 and shifted the transmission from Reverse to Drive (back and forth a bit) and then exercised the 4X4 and it seems to have helped - didn't fix, just seemed to help. No doubt, there sure seems to be way more play that should be expected and with as much torque as this engine produces, one would sure notice any play. Would sure like to know if even more folks are seeing the same thing
07-11-2011, 11:52 PM
#27
I looked at this again this evening and I honestly cannot tell if the play is in the rear end or the transfer case. I locked mine in 4X4 and shifted the transmission from Reverse to Drive (back and forth a bit) and then exercised the 4X4 and it seems to have helped - didn't fix, just seemed to help. No doubt, there sure seems to be way more play that should be expected and with as much torque as this engine produces, one would sure notice any play. Would sure like to know if even more folks are seeing the same thing
07-12-2011, 11:17 AM
#28
Senior Member
Thread Starter
07-18-2011, 07:28 AM
#29
Senior Member
Thread Starter
Doesn't seem to be a lot of traction with others around this; however, I believe we are onto something if only for our own needs. If you get yours into a dealer or figure something out, would appreciate you letting me know. I will do the same, as I hope to have time to get mine to the dealer in the next 2-3 weeks.
08-30-2011, 01:07 PM
#30
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hope this give some insight or helps
Harsh shifts can be considered characteristic in some of our newer vehicles when the right conditions are present. Transmissions like the 6R80 used in this truck have a very high level of adaptability, shift timing and intensity can be adjusted quickly in response to driver inputs but it can also be learned based on repeat driver inputs. There is a reference in the Vehicle Owner Guide, under Driving and Automatic Transmission. The learned behavior is typically what leads to unwanted harsh shifts. Certain types of driving can teach the transmission to command higher pressure in anticipation of a high load or sudden load change, some of the most common driving inputs to cause this are stop and go driving, pulling a trailer, quick stops followed by heavy acceleration and rolling stops. These scenarios create a complete lack of load on coast down or braking followed by a sudden high load downshift as the vehicle accelerates, once the TCM learns this behavior it can shift hard even on a gentle accel or low load accel from a stop. This is not an indication of failure; the firm shifts are actually a self preservation measure to prevent slippage and premature wear. If you clear the vehicle KAM and adaptive shift strategies and the concern is gone for a few hundred miles, the shifts are learned and no repair is available. posted from ford tech hotline