Transmission Adaptive Learning
 

2008 F350 4x4 Super Cab Long Bed 6.4 Stock


A couple of times in the last few months I have experienced a really hard shift into 2nd when accelerating in slow-stop-go traffic. The truck shudders similar to losing traction on ice and then regaining traction on tarmac.


I normally tow 8,000 lbs most of the time but recently have not had the trailer hooked up.


Is the transmission relearning or are these hard shifts something that should be looked at.


I have owned the truck from new and am very light footed.


Thanks for any help, John in the UK

The transmission has nothing to relearn nor any capability to relearn and remember. It's the PCM that performs that function.

You should get it looked at by a specialist.

The term relearning is a misnomer. The PCM is learning the transmission on every shift for the life of the vehicle.

It's possible that it learned something wrong and that caused the harsh shift, but I have never seen that happen on a 1-2 shift. It can happen on a 2-3 or 3-5, but the 1-2 and 5-6 are too simple of a shift for that to happen.

Thank you both for your replies.


I assumed the very harsh shift was 1-2 because I was moving very slow but it could have been 2-3. I don't know.


However, recently I have been using tow haul around town & hilly/winding roads, overdrive on highways and it has been shifting just fine. Incidentally I have 3.73 axles and 35" tires.


Not sure what to do now - do I take it to a transmission shop or do I wait and see if the harsh shifting returns?


John in the UK

I'd wait to see if it returns.

Shop, like your physician, will always find something. I would wait.

Subscribed... I've noticed a few times lately that mine gives a harsh 2-3 shift. Not always, but sometimes...

Due to the nature of how the 2-3 shift is performed, once in a while you will get a harsh shift. It's releasing a clutch and applying another clutch to make that shift. If one finishes what it's doing more than 0.030 seconds faster than the other one it is going to be a bad shift. It proved to be impossible to make that shift perfect 100% of the time.

Mark, my understanding is that the 5R110 is a six speed dual stage transmission, basically a two speed automatic and a three speed automatic. Do you mind elaborating on this? I'd appreciate knowing how it shifts through the gears, which shifts change just one of the two stages and which shifts change both.

Brian

mark..i have a 2010 king ranch 5.4 and you seem to be the guy to answer my question...my truck feels like its getting stuck between gears while driving at any speed and then it will shift and do the same thing over again,almost like ridind over a very low rumble strip its not the suspension ive ruled everything out with the exception of the tranny..i also have the driveshaft clunk isssue...is this related to the shimmy i feel not letting the driveshaft go where it needs?..ive also been told to get the tranny reflashed is there a cost involved with the reflash out of warranty?
thanks ahead of time for any and all answers...im kinda at a loss.

You are correct. The five speed TorqShift (2003-2010) has six ratios, created by a two speed gearset in front of a three speed gearset.

The two speed ratios are 1:1 and 0.71:1
The three speed ratios are 3.09:1, 1.54:1, and 1:1. The first gear ratios changed a bit over the years, but only about 1%.

First gear is both gearsets in low gear. That is 1:1 times 3.09:1 = 3.09:1
Second gear upshifts the two speed, so it is 0.71:1 times 3.09:1 = 2.2:1
Third gear downshifts the two speed AND upshifts the three speed, 1:1 times 1.54:1 = 1.54:1
Fourth gear is usually not used, it is 0.71:1 times 1.54:1 = 1.09:1*
Fifth gear upshifts the three speed (the two speed is already in 1:1 from third gear), so it is 1:1 times 1:1, which is 1:1
Sixth gear upshifts the two speed to 0.71:1, so it is 0.71:1 times 1:1, which is the overdrive ratio of 0.71:1.

* Fourth gear is used in place of fifth gear when the trans is colder than 0F. We could not make the 3-5 shift work at cold temps, but the 3-4 worked fine. So that's what you get. There is no 1:1 ratio available when the transmission temp is colder than 0F. Fourth can also be reached on a full throttle kickdown from sixth gear at a speed just higher than the maximum speed to go to third gear from sixth.

The driveshaft clunk could very well be related. The driveshaft needs to come out and the slip spline needs to be greased. Ford sells a special grease for this that will last MUCH longer than most other greases. I'd do that first and see if both issues go away.

thank you sir..you are a gentleman and a scholar..

My 2011 F350 6.2l will do a hard shift from 2 to 3 every once and awhile. I will be accelerating normally from a dead stop and the engine will start to race because it's not shifting. I let up on the accelerator and the engine will slowly wind down and then slam into third.

If you need assistance with the proper way to grease the slip splines follow this link. I get into it about 1/2 way through the thread. I've preformed this on my 08 and now my 11.

https://www.ford-trucks.com/forums/1...=droldsmorland

Off subject a little as were discussing the 5R110W trans. 6.2 uses the 6R140. How many miles on the fluid and filter and the transmission?