Tranny/shifting issue

[Jackpine]

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

[stryker6040]

Originally Posted by JackandJanet

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

[stryker6040]

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

[88Racing]

Originally Posted by stryker6040

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

[Jackpine]

Originally Posted by stryker6040

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

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

[stryker6040]

Originally Posted by JackandJanet

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

[Jackpine]

Originally Posted by stryker6040

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

[stryker6040]

Originally Posted by JackandJanet

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

[Jackpine]

Originally Posted by stryker6040

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