Revs between shifts. - Diesel Forum

NFA_Fun · 11-09-2006, 05:10 PM

The truck in my sig, 07 with 37" tires will sometimes rev the engine between shifts. The only mod besides the lift is a MBRP exhaust and a speedometer calibration device. No programmer or intake. It does this sporadicly and only under normal to light driving conditions. In addition, maybe once ever two weeks, I will get a very harsh down shift to first gear while coasting up to a red light. Tow / Haul is not engaged when this happens. When driving with a heavy foot or towing it shifts perfect! No warning lights and all fluids are clean and full.

Any ideas? [img]/ubbthreads/images/graemlins/shrug.gif[/img]

GrampyJim · 11-09-2006, 10:50 PM

No warning lights does not automatically guarranty no codes.... A good scan tool is most often my first weapon of choice...

Roger_007 · 11-10-2006, 01:00 PM

My 06' does the same thing by sometimes rev'ing between shifts usually around 3rd. The service dept told my it is the torque converter shifting in and the truck is searching for the best gear at that speed/load etc based upon several factors.

So it would have a lot to do with load and acceleration at a given point.

Sounds normal for the 6 speed auto.

btw: I think they discontinued the 6 speed auto, and a replacement is coming out with the new 08' 6.4L

JasonBarhorst · 11-10-2006, 04:37 PM

Same here too around 3rd gear. I am thinking about taking it back in because it is getting anoying.

KYSkipper · 11-10-2006, 07:08 PM

Just a guess, but it's probably got something to do with the computer controlling the throttle. Mine is a 6 spd manual so I'm not that familiar with the autos, but I do know that the computer somehow controls how the throttle on the engine responds to the pedal in the floor. It's aggrivating as crap on a manual tranny. On my 04 Diesel, on a start from stopped, the computer will only allow so much throttle regardless of if you mash the pedal through the floorboard. IMO, it doesn't allow enough throttle and that in part is one of the problems with this set up.

A few weeks ago when Ford was actually talking like they might buy mine back, I test drove a 5.4 gasser to see if I thought I could stand going back to gas given the myriad of problems with the 6.0 diesel. One of the 2 5.4's I drove had a 6 speed manual and when you came to a stop, mashed in the clutch and took it out of gear, the computer would hold the throttle at about 2000 rpm's for several seconds. To say the least, that was aggrivating.

Why these trucks are engineered like this, I have no idea. I'd like to control my own throttle not have some computer that can't see the road do it for me.

Back when my diesel was new and the engine running properly, you had to be real careful with it on wet mountain roads. Going into a turn you would let up on the throttle expecting the tranny to slow the truck down going into a curve and the dang throttle would stick and scare the crap out of you. I picked the diesel up at Ramey Ford in Johnson City, Tn and brought it back to my dealer in Kentucky. On the way back it was pouring the rain and the 1st time I came into a hard curve I came one ace of wrecking the truck. I let off the throttle and it backed off a little then picked up on it's own and took off. Luckily nothing else was coming as the hind end did get away from me a little. I learned to take it out of gear and/or hold the brake. Really aggrivating.

Skipper

NFA_Fun · 11-10-2006, 08:27 PM

G_J, Will be hooking that up next to take a look as to what is going on. It is amazing how every truck is so so different.

JimBeam_n_Me · 11-19-2006, 01:08 PM

NFA-

I have an 05 350 4x, and this problem has been annoying the f out of me for a year.
The wizards at the dealer have had this thing in and out of there changing solenoids, reprogramming the OB Computer, and now Replacing the entire TS Auto. Th truck has been in there 6 times. The first 3 they exclaimed, "we can't find a problem".

I picked up the truck this Sat. AM and all seemed OK on a brand new TS. Drove it about 20 miles and the problem between 3 and 4 happened again. I about put my fist through the window.

Here is how it has been described by myself and others:

When driving the truck under "no load", meaning no heavy accel or tow, the transmission "flare shifts" between gears.

It almost seems like there is an issue with the valve body not "positively shifting" between gears. But that's not it it appears in this case. As far as the computer goes, that is a possibility, but I don't have a schematic of how the computers logic controls the shift behavior of the trans.

I about an inch away from filing a claim against Ford and the Dealer for negligence, as they have had ample opportunity to repair the issue over 6 occassions, the longest being three weeks.

Maybe suggest you demand the issue repaired, or let them know you are going to pursue legal alternatives.

Best,

GrampyJim · 11-19-2006, 02:25 PM

These trucks a nearly top heavy in electronics... and it isn't going to get any "better"....

For your concern (or any other concern for that matter) we need to ensure that our "easy" basics are covered before we do anything else...

Here is how it would go in our shop.... no exceptions... for your particular concern....

A quick visual... fluid level/condition/odour... a good look at the lift kit (I've seen too many shoddy "professional" installations) to be sure my techs are in a truck I think is safe to drive and a road test to verify the concern (if I can't make it happen, what can I fix?).

If I couldn't get it to happen for me, I will still scan for codes just to be sure I'm not missing something. If I discover your speedometer device, I will probably chastise you for not unhooking it and re-evaluating the concern first.... I am not familiar with many aftermarket devices.... my plate is full with those things I NEED to know to do MY job well. If any of these aftermarket suppliers are willing to fund my training on their devices, I would be more than happy to accept.

Once we are positive that the aftermarket device doesn't play a role in the concern and if we do have (at the very least) memory codes to work with, we can decide on a diagnsotic process.... The 5R110 is a very robust and dependable unit (aside from the "built in" concerns in the early days)... Of course, no decisions are complete without a visit to OASIS... something that too many techs don't use enough....

Since this trans doesn't have a "valve body" in the traditional sense, we might suspect a concern with the EPC (Electronic Pressure Control) solenoid (if all else looks good)... but one would expect some sort of transmission code to be set.

As you might have noticed, a good portion of what I am going to be looking at involves the use of a very capable scan tool. At some point, I may need to spend some time reviewing a "snapshot" of a particular event.... Scan tool diagnostics play a large part in my day to day routine. Ford wont pay for "shot gun" repairs and my boss wont keep me around if I become the king of the chargeback.

Your truck should still be under warranty... if something should "happen" during the course of your diagnostic or repair attempts, there remains the possibility that your warranty may be revoked.

I don't often come across units where an owner has attempted backyard fixes, but when I do, it rarely makes my job easier and, too often, the root concern gets hidden...

JimBeam_n_Me · 11-19-2006, 02:41 PM

Grampy- My truck is bone stock. This flare shifting in between gears still exists, even after a complete TorqShift replacement.
What do you think IYO is any other possibility?
-JimBeam_n_Me.

bigwhite1 · 11-19-2006, 05:36 PM

i just got an 06 and it does it between 2nd and 3rd and that's it and only when i accelerate very slow. in tow /haul mode it doesn't happen at all. in other vehicles i've had, this used to be called slipping and i think that's what's happenning now. my 04 didn't do this. i'm sure it means somethings wrong with the transmission and i'll wait to see if it goes away after a few miles, but my experience says it won't.

snoeproe · 11-19-2006, 08:45 PM

i have noticed the motor rev up while shifting between 2nd and 3rd on my 05 as well. it doesn't do it often, maybe once or twice a week, but it does do it.

GrampyJim · 11-19-2006, 09:22 PM

The 5R110 is totally electronic controlled... without a proper diagnostic work up, anything is going to be a time wasting SWAG. The TCM has an adaptive memory.... if we drive in one manner for an extended period (or if someone else drives the truck for any length of time), the TCM can learn a "new" strategy. If something in the driving "environment" suddenly changes, we might view some of the process as a concern....

Consider.... if we drive agressively as a rule and suddenly adjust our pattern to something more conservative, the TCM/PCM will defuel (detorque) the powertrain in it's accustomed manner until it learns "different". This aggressive defuelling *may* be mistaken for a concern.....

But the only way to be sure is to perform some diagnostics with the scan tool.. codes first. There are three speed sensors on this transmission.... If the trans is "slipping" the TCM will log a DTC to the effect that it didn't see an expected rpm change.

There is no "backyard" stuff I can recommend for your concern... It'd be about the same as having your doctor describe an appendectomy over the phone

luke0204 · 11-20-2006, 12:24 PM

My 2005 has done it pretty much from day 1. Most of the time it does it when I'm in city type traffic, during normal driving it hardly ever does it. In my experience it comes from a driving style change. It annoys me but I've come to the realization I'll have to live with it. I have an extended warranty so if it wants to blow it can go right ahead. I've got 46K on the ticker and it still works fine.

Nothing in this world is perfect so if that is the worst thing your truck is doing I wouldn't worry about it. You could have one of those "bad" 6.0L's that leaves you sitting.

ZBODaytona · 11-20-2006, 02:54 PM

My 05 did it sometimes as well. It only did it when during a slow excel going from 2-3 too. Though in the last 15,000 it hasn't done it anymore. I figured since it happened infrequent it was from a change in driving habit (maybe goosed it more just before or not enough) and the tranny trying to figure out what i was doing....