Tranny/shifting issue
 

Using my 87 custom performance tune it seems my truck too has the gear lock up problem. it cant seem to make up its mind between 3rd and 4th between 50mph and 60mph on flat road with no load. it will go to 4th but wont lock then all of a sudden it will back down to 3rd and lock for a second before it think it should be back in 4th but doesnt lock there either.

Also having an rpm issue while driving on highway with CC and AC on which wasnt there before on the canned gryphon. RPMs seem to surge for about 1-3 seconds every mile or so. It feels really weird cause out of no where the truck will just start to pull for no reason and the exhuast will get louder, and then goes away. With the AC off there doesnt seem to be an issue.

First of all are you still running a tb spacer?
If you are take it out and use it as a paper weight.
If you have removed it from your truck also remove it from the user cp.
Second of all these conditions are not present when at stock? Right?
Try cleaning the maf sensor with maf sensor cleaner. Also check your tb and make sure its clean.
As far as the shifting and non lock conditions I will post a link of this thread in the moderator's help section. Also what year is you truck?


Lars

The spacer has been in the truck since a few weeks after i bought it. at that time i had the spacer and an airaid jr kit with the intake tube and replacment filter
Correct the conditions were not present at stock or using the canned tunes only after receiving the custom tunes. the maf sensor is clean and so is the tb and it moves freely just like the stock one. i had my custom tunes wrote around the mods in my profile

my truck is a 2008 F150screw 5.4

What I was trying to say about the tb spacer is it doesn't do a thing for the truck. Just read this link: http://www.f150online.com/forums/oth...ml#post3688662

Or do a search on here.

I too had this installed. Now its on my garage wall of shame.

Hopefully Bill or Corey get some input in here. About what's going on.

Lars

Stryker, if you didn't notice the one reference to this in the link that Lars posted, the throttle body spacer seemed to give modest gains back when engines had carburetors. They seem to do nothing either pro or con for a fuel injected vehicle except, in some cases, cause noise.

I see them as an unnecessary complication that should not be used under the K.I.S.S. principle. My advice would also be to take it off.

It really sounds to me like the TC on your truck is sensing load and is unlocking, then locking back up again. You could check for this of course if you monitored "Comm Gear" as one of your PIDs. I might help Bill fix the issue if you were able to either confirm or reject this hypothesis.

- Jack

thats what i had on my PID when it started doing it. i was on a flat road going 55 when it first happened then all of a sudden it when down to 3rd and locked for a second then back up into 4th with no lock and then it kicked back down to 3rd with no lock again so then i went to 60mph and it did the same thing

I am going to remove the TB spacer this weekend on everyones recommendation. didnt know they were so "hated" in a sense lol

I don't "hate" tb spacers. They just open the door for another place for vacuum leak to happen. I don't know what yours sounds like but mine whistled a lot.

Lars

Good post! I think this can help Bill pinpoint the cause, when he has time to get to it, which hopefully, will happen soon. It's really difficult for us "laypersons" to suggest any cures, when we've never had anything like this occur to us.

The ONLY thing I ever noticed, as I've posted too many times, was a tendency for the transmission and TC to downshift/unlock too quickly under fairly minor load. This has been tamed by my adjusting the part throttle shiftpoints and TC lock/unlock points downwards.

- Jack

what are your settings so i can try them out and see if it helps. im rather dumbs when it comes to this kinda stuff so please be detailed. thanks

Sure, it's not hard. For any power tune (you can "re-do" the one you're using), once you select the tune level, select "Custom Options". If you've done this before, make sure you "Reload Previous Settings", as the first step once you're in the Custom Options menu. If you've never used Custom Options, please read through my Q & A on this confusing menu here: http://dygytalworld.ehost-services13...ead.php?t=1101 (in fact, it would be a good idea to do it regardless).

Once you insure that your tire size and gear ratio are still correct and have all the other settings to your liking, Go to the "Part Throttle Upshift/Downshift" and "Torque Converter Lock/Unlock" choices. These change the speed at which these events happen by a small amount. As I recall, the Up/Downshift points can be adjusted +/-2, +/-3, and +/-5 mph for each gear change. I wanted mine to change at a lower speed, so I adjusted all of them to the negative maximum. Supposedly, this can improve your fuel economy a bit by getting you into higher gears sooner and keeping you there longer. I just wanted to reduce the tendency of the transmission to downshift when I thought there was still a power reserve.

I did the same thing with the Torque Converter Lock/Unlock points. These are a bit more aggressive and there are four of them (one for each gear). They can be adjusted +/-2, +/-3, +/-5 and +/-10. Again, I reset all of them to the negative maximum, hoping to keep the TC locked up longer.

It seems to have helped. I don't get the overeager unlocking on the slightest incline that I used to have.

Note these "Part Throttle" adjustments have no effect whatsoever on WOT shifts. And, since part throttle shift and TC change patterns depend on both speed and throttle position, just a little more throttle at a given speed is all it takes to cause a downshift or TC unlock if that is wanted.

Hope this makes sense.

- Jack

did you adjust the downshifts to the negitive max along with the upshifts same thing for the tc? negitive on up side and down side

Yes, I did. As I just posted in another thread. Both part throttle shift and TC behavior are dependent on both speed and throttle position. At very low throttle input, the changes occur at lower speeds than they do if you are feeding the engine gas, perhaps to accelerate quicker but not at WOT. On deceleration (coasting), the shift down should happen at lower speeds too.

The intent is to keep the engine RPM as low as possible, while not sacrificing driveability. The power is still there, if I demand it with a heavier foot.

- Jack

one other thing i notcied from going to the canned tune to the custom tune is the shifts seems less harsh. with the canned tune when it shifted you could really feel it almost like there was a shift kit on the truck. now with the custom tunes its a lot smoother. is this normal for the custom tune. off subject my exhuast seems not as loud

Bill adjusts at least three things when he sets up your shifts in a custom tune. I doubt they would match what he's set up in the canned tunes, so it doesn't surprise me it would feel different. I don't know if it's normal for it to feel "smoother"; mine simply feels "right" (and, of course, I'm used to it now).

The change in exhaust sound is probably the result of the way Bill has mapped the fueling and timing.

- Jack